CA2329392A1 - Tapping tee - Google Patents
Tapping tee Download PDFInfo
- Publication number
- CA2329392A1 CA2329392A1 CA 2329392 CA2329392A CA2329392A1 CA 2329392 A1 CA2329392 A1 CA 2329392A1 CA 2329392 CA2329392 CA 2329392 CA 2329392 A CA2329392 A CA 2329392A CA 2329392 A1 CA2329392 A1 CA 2329392A1
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- Prior art keywords
- tapping
- tee
- cutter
- tool
- section
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
Abstract
The present invention provides an improved tapping tee for tapping into main pipelines under pressure, for example, for tapping into natural gas lines carrying gas under pressure. The new tapping tee has a smooth bore in the tower/cutter mechanism. The tapping tee contains three components:
(a) tee-shaped structure having three cylindrical hollow sections for allowing flow of fluid from the main line, allowing flow of fluid to a service line, and allowing access of a tapping tool to a cutter means; (b) unthreaded annular cutter means fitting in and against the unthreaded cylindrical hollow section of the tee-shaped structure; and (c) an O-ring mounted in an upper portion of the annular cutter means and forming a seal against the inside wall of the unthreaded cylindrical hollow section of the tee-shaped structure.
(a) tee-shaped structure having three cylindrical hollow sections for allowing flow of fluid from the main line, allowing flow of fluid to a service line, and allowing access of a tapping tool to a cutter means; (b) unthreaded annular cutter means fitting in and against the unthreaded cylindrical hollow section of the tee-shaped structure; and (c) an O-ring mounted in an upper portion of the annular cutter means and forming a seal against the inside wall of the unthreaded cylindrical hollow section of the tee-shaped structure.
Description
_1_ TAPPING TEE
2 CROSS-REFERENCE TO RELATED APPLI ATI~NS
3 This application claims priority from U.S. Provisional Application Serial
4 No. 60!173,008, filed December 22, 1999.
FIELD OF THE INVENTION
6 The present invention relates to an apparatus and method for connecting one 7 fluid flow line to another fluid flow line. More particularly, to an improved 8 "tapping tee" device, useful for connecting a service line, such as a gas or 9 water service pipeline to a main gas or water pipeline.
BACKGR~UNb OF THE INVENTION
11 Tapping tees are typically used to tap into or connect into a main fluid flow 12 line so as to connect the main line to a branch line, such as to a service line.
13 For example, when a new home is built, to bring gas ar water service into the 14 home, a tapping tee may be used to connect flow from the local utility's main line to a smaller "service" line running to the new home from a main line.
16 A tapping tee assembly generally incorporates a cutter contained in a 17 mounting collar portion of the tapping tee. The tapping tee has a saddle 18 portion which conforms to the diameter of the pipe to be tapped, a 19 through-bore path for the cutter, and also has a side outlet adapted for 2f~ mounting to a service or branch connection. The tapping device is typically 21 T-shaped, in that one leg of the T attaches to the main line, another leg of the 22 T attaches to the service or branch line, and a third leg comprises a central 23 bare or tower through which a tapping tool may be inserted and connected to 24 a cutter. The cutter is moved downwardly using the tapping tool, and typically rotated so as to cut into the main line.
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1 Thus, in operation, the tapping tee is first attached securely to the main 2 pipeline to be tapped. Then, the cutter is advanced through a sidewall of the 3 main pipe, thus cutting an opening into the main pipeline. The cutter is then 4 usually withdrawn from the main pipe to establish an open fluid passage between the main pipe and the side outlet of the tee assembly. Typically in 6 the prior art, movement of the cutter within the tee assembly is accomplished 7 by using drive threads which are provided externally on a section of the cutter.
8 and lintemally within a through-bore of the tapping tee. The through-bore of 9 the tapping tee is sometimes referred to as the "tower" of the tee.
Tapping tees of the prior art adapted primarily for metal pipe include U.S.
91 Patent Nos. 3,094,137; 3,264,907; 3,277,683 and 3,285,398.
12 Numerous tapping tees primarily for plastic pipe have also been disclosed.
13 For example, U.S. Patent No. 4,730,636 discloses a tapping tee wherein the 14 cutter is advance by threading the cutter down the internal bore of the tapping tee and progressing the cutter into the main line. Thus, according tv the 16 tapping method of the '636 patent, a cutting tool is rotatably advanced to cut 17 an aperture through the sidewall of the main pipe. Thereafter, the aperture is 18 temporarily spread or expanded radially to a larger dirnensivn and then 19 released. Following release, the cutting tool is rotatably retracted in a second direction opposed to the first direction.
21 According to U.S. Patent No. 4,063,844, again the cutter of the tapping tee 22 apparatus is advanced using threads. The '844 tapping tee uses an annular 23 gasket in the saddle. The saddle is mounted on the main pipe to be tapped, 24 and the gasket is to provide a leak-tight assembly of the saddle against the main pipe.
26 U.S. Patent No. 5,425,395 also operates by threading the cutter down the 2'l internal bore of the tapping tee. According to the '395 patent, the cutter 28 includes an externally threaded region. The threaded region has a first LCO/~,00 ~ ME'I t~0?L1~H~ Ott~T CL8 SZ6$ 9Z : ZT CC: OZ~ZT
1 preselected thread pitch that cooperates with the internally threaded main 2 passage of the tee. Upon rotation of the cutter relative to the body, the cutter 3 is either axially advanced or retracted toward the main conduit. The second 4 end of the cutter also includes a tool receiving recess such as a hex-shaped tool socket that receives an appropriate tool to effect the rotation of the cutter.
. ~, 6 GB 2,271,623A discloses a tapping tee which includes means for inserting a 7 plug, such as a rubber plug, into the top of the tee after the main pipe has 8 been tapped, to thereby effect a permanent seal. The '623A tapping tee is 9 said to be suitable for tapping into a °live" gas distribution main line, that is, a main gas pipeline which is under pressure due to the fuel gas contained in 11 andlor flowing through the main line. Whereas the plug is to accomplish a 12 seal after the tapping operation, the seal during the tapping operation is to be 13 accomplished, in part, by a sealing ring placed inside the apparatus carrying 14 the plug and cutter, as shown by element 1fi in the drawing of 623A.
Friedrichsteld's undated brochure titled "Friedrichsteld FRIALEN Safety 16 Fittings" discloses a tapping tee on page 4_ According to the diagram in this 17 disclosure, a seal ring appears to be located in the cutter. The cutter is 18 threaded and evidently operated by threading the cutter down the central bore 19 for cutting through the main pipeline.
EP 360,312 discloses a tapping tee assembly which includes a valve 21 arrangement directed to preventing leaks to the atmosphere during tapping.
22 UK Patent 1,229,175 discloses a tapping tee with a cutter that is advanced 23 using threading. The cutter contains a seal ring, shown by element 15 in the 24 '175 drawing.
GB 2,310,264A discloses a detachable tapping tee assembly, with a cutter 26 having exterior threads, to be advanced along threads on the interior of the 27 tapping tee bore.
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-t SUMMARY OF THE INVENTION
2 According to the present invention, a tapping tee is provided which comprises:
3 (a) tee-shaped structure having three cylindrical hollow sections for:
4 (1) allowing flow of fluid from the main line;
(2) allowing flow of fluid to a service fine; and 6 (3) allowing access of a tapping tool to a cutter means;
7 (b} unthreaded annular cutter means fitting in unthreaded section (1) of the 8 tee-shaped structure; and 9 (c) an O-ring mounted in an upper portion of the annular cutter means and forming a seal against an inside wall of section (3) of the tee-shaped 19 structure.
12 According to a preferred embodiment of the invention, a tapping tee assembly 13 is provided comprising:
14 (a) means for attaching the tee to a main line;
(b) tee-shaped structure having three cylindrical hollow sections for:
16 (1 ) allowing flow of fluid from the main line;
17 (2) allowing flow of fluid to a service line; and 18 (3) allowing access of a tapping tool to a cutter means;
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FIELD OF THE INVENTION
6 The present invention relates to an apparatus and method for connecting one 7 fluid flow line to another fluid flow line. More particularly, to an improved 8 "tapping tee" device, useful for connecting a service line, such as a gas or 9 water service pipeline to a main gas or water pipeline.
BACKGR~UNb OF THE INVENTION
11 Tapping tees are typically used to tap into or connect into a main fluid flow 12 line so as to connect the main line to a branch line, such as to a service line.
13 For example, when a new home is built, to bring gas ar water service into the 14 home, a tapping tee may be used to connect flow from the local utility's main line to a smaller "service" line running to the new home from a main line.
16 A tapping tee assembly generally incorporates a cutter contained in a 17 mounting collar portion of the tapping tee. The tapping tee has a saddle 18 portion which conforms to the diameter of the pipe to be tapped, a 19 through-bore path for the cutter, and also has a side outlet adapted for 2f~ mounting to a service or branch connection. The tapping device is typically 21 T-shaped, in that one leg of the T attaches to the main line, another leg of the 22 T attaches to the service or branch line, and a third leg comprises a central 23 bare or tower through which a tapping tool may be inserted and connected to 24 a cutter. The cutter is moved downwardly using the tapping tool, and typically rotated so as to cut into the main line.
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1 Thus, in operation, the tapping tee is first attached securely to the main 2 pipeline to be tapped. Then, the cutter is advanced through a sidewall of the 3 main pipe, thus cutting an opening into the main pipeline. The cutter is then 4 usually withdrawn from the main pipe to establish an open fluid passage between the main pipe and the side outlet of the tee assembly. Typically in 6 the prior art, movement of the cutter within the tee assembly is accomplished 7 by using drive threads which are provided externally on a section of the cutter.
8 and lintemally within a through-bore of the tapping tee. The through-bore of 9 the tapping tee is sometimes referred to as the "tower" of the tee.
Tapping tees of the prior art adapted primarily for metal pipe include U.S.
91 Patent Nos. 3,094,137; 3,264,907; 3,277,683 and 3,285,398.
12 Numerous tapping tees primarily for plastic pipe have also been disclosed.
13 For example, U.S. Patent No. 4,730,636 discloses a tapping tee wherein the 14 cutter is advance by threading the cutter down the internal bore of the tapping tee and progressing the cutter into the main line. Thus, according tv the 16 tapping method of the '636 patent, a cutting tool is rotatably advanced to cut 17 an aperture through the sidewall of the main pipe. Thereafter, the aperture is 18 temporarily spread or expanded radially to a larger dirnensivn and then 19 released. Following release, the cutting tool is rotatably retracted in a second direction opposed to the first direction.
21 According to U.S. Patent No. 4,063,844, again the cutter of the tapping tee 22 apparatus is advanced using threads. The '844 tapping tee uses an annular 23 gasket in the saddle. The saddle is mounted on the main pipe to be tapped, 24 and the gasket is to provide a leak-tight assembly of the saddle against the main pipe.
26 U.S. Patent No. 5,425,395 also operates by threading the cutter down the 2'l internal bore of the tapping tee. According to the '395 patent, the cutter 28 includes an externally threaded region. The threaded region has a first LCO/~,00 ~ ME'I t~0?L1~H~ Ott~T CL8 SZ6$ 9Z : ZT CC: OZ~ZT
1 preselected thread pitch that cooperates with the internally threaded main 2 passage of the tee. Upon rotation of the cutter relative to the body, the cutter 3 is either axially advanced or retracted toward the main conduit. The second 4 end of the cutter also includes a tool receiving recess such as a hex-shaped tool socket that receives an appropriate tool to effect the rotation of the cutter.
. ~, 6 GB 2,271,623A discloses a tapping tee which includes means for inserting a 7 plug, such as a rubber plug, into the top of the tee after the main pipe has 8 been tapped, to thereby effect a permanent seal. The '623A tapping tee is 9 said to be suitable for tapping into a °live" gas distribution main line, that is, a main gas pipeline which is under pressure due to the fuel gas contained in 11 andlor flowing through the main line. Whereas the plug is to accomplish a 12 seal after the tapping operation, the seal during the tapping operation is to be 13 accomplished, in part, by a sealing ring placed inside the apparatus carrying 14 the plug and cutter, as shown by element 1fi in the drawing of 623A.
Friedrichsteld's undated brochure titled "Friedrichsteld FRIALEN Safety 16 Fittings" discloses a tapping tee on page 4_ According to the diagram in this 17 disclosure, a seal ring appears to be located in the cutter. The cutter is 18 threaded and evidently operated by threading the cutter down the central bore 19 for cutting through the main pipeline.
EP 360,312 discloses a tapping tee assembly which includes a valve 21 arrangement directed to preventing leaks to the atmosphere during tapping.
22 UK Patent 1,229,175 discloses a tapping tee with a cutter that is advanced 23 using threading. The cutter contains a seal ring, shown by element 15 in the 24 '175 drawing.
GB 2,310,264A discloses a detachable tapping tee assembly, with a cutter 26 having exterior threads, to be advanced along threads on the interior of the 27 tapping tee bore.
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-t SUMMARY OF THE INVENTION
2 According to the present invention, a tapping tee is provided which comprises:
3 (a) tee-shaped structure having three cylindrical hollow sections for:
4 (1) allowing flow of fluid from the main line;
(2) allowing flow of fluid to a service fine; and 6 (3) allowing access of a tapping tool to a cutter means;
7 (b} unthreaded annular cutter means fitting in unthreaded section (1) of the 8 tee-shaped structure; and 9 (c) an O-ring mounted in an upper portion of the annular cutter means and forming a seal against an inside wall of section (3) of the tee-shaped 19 structure.
12 According to a preferred embodiment of the invention, a tapping tee assembly 13 is provided comprising:
14 (a) means for attaching the tee to a main line;
(b) tee-shaped structure having three cylindrical hollow sections for:
16 (1 ) allowing flow of fluid from the main line;
17 (2) allowing flow of fluid to a service line; and 18 (3) allowing access of a tapping tool to a cutter means;
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-5-1 (c) unthreaded annular cutter means fitting in unthreaded section (1) of the 2 tee-shaped structure;
3 (d) an O-ring mounted in an upper portion of the annular cutter means and 4 forming a seal against an inside wall of section (3) of the tee-shaped structure; and
3 (d) an O-ring mounted in an upper portion of the annular cutter means and 4 forming a seal against an inside wall of section (3) of the tee-shaped structure; and
6 (e) a tapping tool mounted on section (3), which tool can drive the cutting
7 means through the unthreaded section (3), past section (2), and through
8 the main line, and which tool can then withdraw the cutting means from
9 the main line back into section (3) to thereby allow fluid in the main line to flow into section {2).
11 Arnong other factors, the present invention is based on our finding that a 12 highly effective tapping tee is achieved in terms of cost, leakage prevention, 13 and ease of use using our design wherein the cutter is moved through the 14 inner bore without use of thread on the cutter and the inner bore, and wherein an 0-ring seal is located integral to the upper portion of the cutter. We have 18 found the present tapping tee is especially effective for tapping into plastic 17 pipe, such as polyethylene pipe. We have found the present tapping tee 18 achieves very low leakage through the tee of the fluid, such as gas under 19 pressure or water under pressure, in the main pipeline which is being tapped into.
21 Because the tapping tee and method of the present invention achieves high 22 protection against leakage, we refer to it as a minimum blowby (sometimes 23 "MBB'~ tapping tee.
24 According to a pref~rred embodiment of the present invention, the tapping tool is a detachable tool adapted to fit lengthwise down the center bore of 28 section (3}, and to detechably engage a cutter part (b). Preferably, the 27 detachable tapping tool is attachable and detachable to the cutter by a spring LC0;800~ M~"I h0~IA3H'J OBfifi CLB ~ZB~ 9Z:ZT CC%OZiZT
-6_ 1 ball or threaded screw mechanism, most preferably a threaded screw 2 mechanism. We have found the threaded connection to the cutter to be more 3 reliable than the spring ball mechanism. Preferably, the detachable tool 4 assembly is attachable, to the outer wall which houses or encloses section (3) of the tapping tee, by threaded connection of an annular section housing the 6 tapping tool. Preferably, the tapping tool assembly (including the annular 7 section housing) is detachable by unscrewing the threaded connection from 8 the wall which encloses section (3) of the tapping tee.
9 In one preferred embodiment of the present invention, an overall tapping tee apparatus assembly is provided, comprising:
11 (a) means for attaching the tee to a main line;
12 (b) tee-shaped structure having three cylindrical hollow sections for:
13 (1 ) allowing flow of fluid from the main line;
14 (2} allowing flow of fluid to a service line; and (3) allowing access of a tapping tool to a cutter means;
16 (c) unthreaded annular cutter means fitting in unthreaded section (1) of the 17 tee-shaped structure;
18 (d} an O-ring mounted in an upper portion of the annular cutter means and 19 forming a seal against an inside wall of section (3) of the tee-shaped structure; and 21 (e) a tapping tool mounted on section (3), which tool can drive the cutting 22 means through the unthreaded section (3), past section (2), and through 23 the main line, and which tool can then withdraw the cutting means from LCOi800~ MT''I L~02I~1HH~ OBbfi CLg SZB~ 9Z:ZT ~~%OZiZT
1 the main line back into section (3) to thereby allow fluid in the main line 2 to flow into section (2).
3 Preferably, the assembly comprises:
4 (a) an elongated cylindrical tapping tool member adapted to connect to the cutter (3) and to drive the cutter through the main fine;
6 (b) a tapping tool cap adapted to connect to the top of section (3} of the 7 tee-shaped structure;
8 (c) a tapping tool body which fits above the tapping tool cap and contains 9 inner threads;
(d) a threaded drive screw, which matches the inner threads of (c}, and 11 which is flitted onto a center part of the tapping tool, for rotatably driving 12 the cutter (c} through the main line;
13 (e) a handle on the tapping tool member to allow rotation of the tapping tool 14 member in said matching threads; and (f) means to fix the cylindrical tapping tool into place in the tapping tool i6 assembly in a position for rotatably driving the cutter (c) through the 17 main line.
18 According to a particularly preferred embodiment of the present invention, a 19 tapping tee apparatus assembly is provided wherein the tapping tool cap is cylindrical in shape, with a top having a central hole sized to receive the 21 cylindrical tapping tool and preferably having at least a few thousands of an 22 inch clearance around the cylindrical tapping toot, more preferably 0.003 inch 23 to 0.1 inch clearance, and wherein the top part of the tapping tool cap forms a 24 tee shape by indenfiations along the cylindrical walls of the tapping tool cap, LCOiDTO~ ,11V'1 N021<131ia Ogt~~ EL8 SZB~$ LZ:ZT ~C/OZ/ZT
1 and wherein the tee shape is adapted to slot into a receiving portion of the 2 tapping tool body.
3 The slotted tee connection preferred embodiment of the present invention 4 and its advantage in allowing for minor misalignment yet attachment of the tapping tool to the cutter is further discussed below and is illustrated by the 6 drawings.
7 In the present invention, preferably the tapping tee tower has a narrower 8 diameter (see 95 in Figure 2) at the upper or top part of section (3}, than the 9 diameter along the length of section (3) that the cutter traverses, so as to prevent the cutter from escaping ar exiting the tower when the tapping is 11 completed and the tapping tool is drawn upward to allow flow to the service 12 line or when the tapping tool is withdrawn from the tapping tee.
13 Preferably, the 0-ring is compressed against the inside wall of section (3) at a 14 compression between 0.5 and 50 percent, more preferably between 1 and 25 percent, and most preferably between 15 and 25 percent. By compression 16 of the 0-ring is meant the percent deformity of the normally circular cross 17 section of the d-ring into an oval or elliptical shape. Thus, for a 25 percent 18 compression, if the O-ring started with a circular cross section diameter of 19 0.1 inch, the compressed minor axis of the oval shaped 0-ring cross section would be 0.075 inch.
22 Figure 1 is a schematic diagram showing a tapping tee in an overall tapping 23 assembly, attached to a main line. The cutter is in a starting position and has 24 not yet been driven forward through the wall of the main line-Figure 2 is the same tapping tee assembly, but showing the cutter advanced 26 through the wall of the main line.
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_g_ 1 Figure 3 is a schematic drawing of the cutter.
2 Figure 4 is a more complete drawing of the tapping tee assembly shown in 3 Figure 2.
4 Figure 5 is a schematic drawing of the tapping tee brass cap, which is part of Figure 4.
6 Figure 6 is a schematic drawing of the tapping tool portion of the tapping tee.
7 Figure 7 is a schematic drawing of the tapping tee wrench tool.
g DETAILED DESCRIPTIQN OF THE INVENTION
9 As mentioned above, one of the advantages of the tapping tee of the present invention is that it prevents leakage, from the main line being tapped into, 11 through the tapping tee. Accordingly, it may be referred to as a minimum 12 blowby (MBB) tapping tee.
13 the MBB tapping tee design of the present invention is applicable to standard 14 volume tapping tees (SVTT) and high volume tapping tees (HVTT). HVTT
are larger than SVTT to accommodate cutters that are typically two or more 16 times larger diameter compared to SVTT cutters. Thus, the volume of flow 17 through a HV1'T compared to that through a SVTT is many times greater.
18 The new MBl3 design can be attached to gas mains and other main lines by 19 methods as used in the past. Conventional tapping tees are often saddle fused to gas mains, and users will be able to do the same with the new MBB
21 tee, and can use the same saddle fusion equipment they now use.
22 Current and MBB tapping tees may use the same tapping tee body size and 23 shape, and the same means of connecting to the main pipe and to the service 24 pipe. However, the present invention involves, as a key feature, a sealed LCO:ZTO~ M~''I h0?Ll3Ha 08~fi ~18 9Z6$ LZ:ZT ~~:OZiZi
11 Arnong other factors, the present invention is based on our finding that a 12 highly effective tapping tee is achieved in terms of cost, leakage prevention, 13 and ease of use using our design wherein the cutter is moved through the 14 inner bore without use of thread on the cutter and the inner bore, and wherein an 0-ring seal is located integral to the upper portion of the cutter. We have 18 found the present tapping tee is especially effective for tapping into plastic 17 pipe, such as polyethylene pipe. We have found the present tapping tee 18 achieves very low leakage through the tee of the fluid, such as gas under 19 pressure or water under pressure, in the main pipeline which is being tapped into.
21 Because the tapping tee and method of the present invention achieves high 22 protection against leakage, we refer to it as a minimum blowby (sometimes 23 "MBB'~ tapping tee.
24 According to a pref~rred embodiment of the present invention, the tapping tool is a detachable tool adapted to fit lengthwise down the center bore of 28 section (3}, and to detechably engage a cutter part (b). Preferably, the 27 detachable tapping tool is attachable and detachable to the cutter by a spring LC0;800~ M~"I h0~IA3H'J OBfifi CLB ~ZB~ 9Z:ZT CC%OZiZT
-6_ 1 ball or threaded screw mechanism, most preferably a threaded screw 2 mechanism. We have found the threaded connection to the cutter to be more 3 reliable than the spring ball mechanism. Preferably, the detachable tool 4 assembly is attachable, to the outer wall which houses or encloses section (3) of the tapping tee, by threaded connection of an annular section housing the 6 tapping tool. Preferably, the tapping tool assembly (including the annular 7 section housing) is detachable by unscrewing the threaded connection from 8 the wall which encloses section (3) of the tapping tee.
9 In one preferred embodiment of the present invention, an overall tapping tee apparatus assembly is provided, comprising:
11 (a) means for attaching the tee to a main line;
12 (b) tee-shaped structure having three cylindrical hollow sections for:
13 (1 ) allowing flow of fluid from the main line;
14 (2} allowing flow of fluid to a service line; and (3) allowing access of a tapping tool to a cutter means;
16 (c) unthreaded annular cutter means fitting in unthreaded section (1) of the 17 tee-shaped structure;
18 (d} an O-ring mounted in an upper portion of the annular cutter means and 19 forming a seal against an inside wall of section (3) of the tee-shaped structure; and 21 (e) a tapping tool mounted on section (3), which tool can drive the cutting 22 means through the unthreaded section (3), past section (2), and through 23 the main line, and which tool can then withdraw the cutting means from LCOi800~ MT''I L~02I~1HH~ OBbfi CLg SZB~ 9Z:ZT ~~%OZiZT
1 the main line back into section (3) to thereby allow fluid in the main line 2 to flow into section (2).
3 Preferably, the assembly comprises:
4 (a) an elongated cylindrical tapping tool member adapted to connect to the cutter (3) and to drive the cutter through the main fine;
6 (b) a tapping tool cap adapted to connect to the top of section (3} of the 7 tee-shaped structure;
8 (c) a tapping tool body which fits above the tapping tool cap and contains 9 inner threads;
(d) a threaded drive screw, which matches the inner threads of (c}, and 11 which is flitted onto a center part of the tapping tool, for rotatably driving 12 the cutter (c} through the main line;
13 (e) a handle on the tapping tool member to allow rotation of the tapping tool 14 member in said matching threads; and (f) means to fix the cylindrical tapping tool into place in the tapping tool i6 assembly in a position for rotatably driving the cutter (c) through the 17 main line.
18 According to a particularly preferred embodiment of the present invention, a 19 tapping tee apparatus assembly is provided wherein the tapping tool cap is cylindrical in shape, with a top having a central hole sized to receive the 21 cylindrical tapping tool and preferably having at least a few thousands of an 22 inch clearance around the cylindrical tapping toot, more preferably 0.003 inch 23 to 0.1 inch clearance, and wherein the top part of the tapping tool cap forms a 24 tee shape by indenfiations along the cylindrical walls of the tapping tool cap, LCOiDTO~ ,11V'1 N021<131ia Ogt~~ EL8 SZB~$ LZ:ZT ~C/OZ/ZT
1 and wherein the tee shape is adapted to slot into a receiving portion of the 2 tapping tool body.
3 The slotted tee connection preferred embodiment of the present invention 4 and its advantage in allowing for minor misalignment yet attachment of the tapping tool to the cutter is further discussed below and is illustrated by the 6 drawings.
7 In the present invention, preferably the tapping tee tower has a narrower 8 diameter (see 95 in Figure 2) at the upper or top part of section (3}, than the 9 diameter along the length of section (3) that the cutter traverses, so as to prevent the cutter from escaping ar exiting the tower when the tapping is 11 completed and the tapping tool is drawn upward to allow flow to the service 12 line or when the tapping tool is withdrawn from the tapping tee.
13 Preferably, the 0-ring is compressed against the inside wall of section (3) at a 14 compression between 0.5 and 50 percent, more preferably between 1 and 25 percent, and most preferably between 15 and 25 percent. By compression 16 of the 0-ring is meant the percent deformity of the normally circular cross 17 section of the d-ring into an oval or elliptical shape. Thus, for a 25 percent 18 compression, if the O-ring started with a circular cross section diameter of 19 0.1 inch, the compressed minor axis of the oval shaped 0-ring cross section would be 0.075 inch.
22 Figure 1 is a schematic diagram showing a tapping tee in an overall tapping 23 assembly, attached to a main line. The cutter is in a starting position and has 24 not yet been driven forward through the wall of the main line-Figure 2 is the same tapping tee assembly, but showing the cutter advanced 26 through the wall of the main line.
LCO/TTO~ MV'7 1102L13Tia 06tfi ~L8 SZ6.g. LZ:ZT ~~:OZ'ZT
_g_ 1 Figure 3 is a schematic drawing of the cutter.
2 Figure 4 is a more complete drawing of the tapping tee assembly shown in 3 Figure 2.
4 Figure 5 is a schematic drawing of the tapping tee brass cap, which is part of Figure 4.
6 Figure 6 is a schematic drawing of the tapping tool portion of the tapping tee.
7 Figure 7 is a schematic drawing of the tapping tee wrench tool.
g DETAILED DESCRIPTIQN OF THE INVENTION
9 As mentioned above, one of the advantages of the tapping tee of the present invention is that it prevents leakage, from the main line being tapped into, 11 through the tapping tee. Accordingly, it may be referred to as a minimum 12 blowby (MBB) tapping tee.
13 the MBB tapping tee design of the present invention is applicable to standard 14 volume tapping tees (SVTT) and high volume tapping tees (HVTT). HVTT
are larger than SVTT to accommodate cutters that are typically two or more 16 times larger diameter compared to SVTT cutters. Thus, the volume of flow 17 through a HV1'T compared to that through a SVTT is many times greater.
18 The new MBl3 design can be attached to gas mains and other main lines by 19 methods as used in the past. Conventional tapping tees are often saddle fused to gas mains, and users will be able to do the same with the new MBB
21 tee, and can use the same saddle fusion equipment they now use.
22 Current and MBB tapping tees may use the same tapping tee body size and 23 shape, and the same means of connecting to the main pipe and to the service 24 pipe. However, the present invention involves, as a key feature, a sealed LCO:ZTO~ M~''I h0?Ll3Ha 08~fi ~18 9Z6$ LZ:ZT ~~:OZiZi
-10-1 cutter design with an unthreaded cutter, and a new tool that is used in tapping 2 the main. In addition, the tapping tool of the present invent;on preferably 3 embodies a novel alignment feature for use in attaching to the tee and to the 4 cutter. This feature is described below.
The general purpose of a tapping tee is to establish a branch (service) pipe 6 connection to a main pipe, preferably without having to depressurize the main 7 pipe. For this purpose, tapping tees have an internal cutter for penetrating or 8 perforating (cutting into) the main line. Tapping tees are sometimes called 9 self-tapping tees.
A principal difference between conventional tapping tee design and the 19 present invention is the new sealed cutter design of the present invention.
In 92 conventional tapping tee design, the cutter is threaded into a threaded bore in 13 the tapping tee body. A removable wrench, usually a hex wrench, is used to 14 screw the cutter down and penetrate the main, then unscrew the cutter back to the tap of the tapping tee. Generally, the cutter is intended far a single 18 use, and so it stays in the tapping tee after main perforation.
17 We are aware of two commercially available sealed tapping tee products, one 1$ referred to as FrialenC~ (sold by F'riedrichsteld of Mannheim, Germany) and 19 one referred to as Fusamatic Multi-Sear" tapping tee (sold by Fusion Group 24 Manufacturing of Chesterfield, England). Both of these commercially 21 available sealed tapping tee designs incorporate a threaded cutter. The 22 Frialen and Fusamatic designs differ in their cutteNtee tower sealing methods 23 but, in both, a threaded cutteNtower arrangement is used, in contrast to the 24 present invention, which does not use a threaded cutterltower arrangement.
Regarding tapping tees which do not seal the tee against gas leakage during 28 hot (main line under pressure from the fluid it carries) tapping, there are 27 numerous examples as discussed above in the background section. Indeed, 28 these are the more common tapping tee designs.
LCOiCTO~ M~'I n;02I:1HH~ 08~fi CL8 9ZB,~ LZ:ZI CC~nZiZT
The general purpose of a tapping tee is to establish a branch (service) pipe 6 connection to a main pipe, preferably without having to depressurize the main 7 pipe. For this purpose, tapping tees have an internal cutter for penetrating or 8 perforating (cutting into) the main line. Tapping tees are sometimes called 9 self-tapping tees.
A principal difference between conventional tapping tee design and the 19 present invention is the new sealed cutter design of the present invention.
In 92 conventional tapping tee design, the cutter is threaded into a threaded bore in 13 the tapping tee body. A removable wrench, usually a hex wrench, is used to 14 screw the cutter down and penetrate the main, then unscrew the cutter back to the tap of the tapping tee. Generally, the cutter is intended far a single 18 use, and so it stays in the tapping tee after main perforation.
17 We are aware of two commercially available sealed tapping tee products, one 1$ referred to as FrialenC~ (sold by F'riedrichsteld of Mannheim, Germany) and 19 one referred to as Fusamatic Multi-Sear" tapping tee (sold by Fusion Group 24 Manufacturing of Chesterfield, England). Both of these commercially 21 available sealed tapping tee designs incorporate a threaded cutter. The 22 Frialen and Fusamatic designs differ in their cutteNtee tower sealing methods 23 but, in both, a threaded cutteNtower arrangement is used, in contrast to the 24 present invention, which does not use a threaded cutterltower arrangement.
Regarding tapping tees which do not seal the tee against gas leakage during 28 hot (main line under pressure from the fluid it carries) tapping, there are 27 numerous examples as discussed above in the background section. Indeed, 28 these are the more common tapping tee designs.
LCOiCTO~ M~'I n;02I:1HH~ 08~fi CL8 9ZB,~ LZ:ZI CC~nZiZT
-11-1 In the M8B design of the present invention, the tapping tee body bore and the 2 cutter are smooth, that is, not threaded. Also, the cutter used in the present 3 invention has an O-ring at the flop that seals against gas leakage. Rather 4 than incx~rporate a threaded mechanism within the tapping tee, the present invention uses a smooth bore for the inner borE of the tower and for the cutter fi outside wall, and also the present invention preferably uses a removable 7 tapping tool. The preferred removable tapping tool design feature of the $ present invention reduces the overall height of the tee tower, enabling a very 9 compact tapping tee design. In comparison, the Frlalen product has the thread mechanism and the sealing cylinder stacked on top of each other.
11 Another feature of the present invention is that the cutter is always sealed,
11 Another feature of the present invention is that the cutter is always sealed,
12 regardless of whether the cutter is being moved up or down in the tee tower,
13 or is in a static position in the tee tower. In the Fusamatic device, (see, for
14 example, WO 98111373), the cutter is sealed only when it is at the topmost position in the tee tower. The Fusamatic design relies on a removable tube 16 being fitted to the top of the cutter to seal the tapping tee when the cutter is 1? Ivwer in the tee tower. If the removable tube is not fitted to the cutter and the 18 cutter is lower in the tee tower, the seal is not effective.
19 Further, the design of the present invention is independent of the means used to connect the tapping tee to the main. The Frialen and the Fusamatic 21 tapping tees are only electrofused to the main.
22 Various materials are currently employed for main lines, such as plastic, 23 particularly polyethylene. Another thermoplastic material, polyarnide 11, 24 PA11, (or nylon 11) is also sometimes used for gas pipe and fittings. The present invention preferably is used with polyethylene, especially High 26 Density Polyethylene (HDPE) but also may be used with other plastics, such 27 PA11.
LCO/bTO~ M~''I 1~O~I<1HH~ 08~D CL6 SZB.g. 8Z:ZT C~/OZ/Zi 1 As indicated above, the tapping tool of the present invention preferably 2 includes a novel articulating or self aligning feature. Although the cutter is in 3 the middle of the tapping tee, it does not need to be pertectly centered in the 4 tapping tee for the device to be fully functional. In the invention, however, the tapping tool detachably threads onto the tapping tee, and concurrently 6 detachably engages the cutter, therefore, misalignment between the tapping 7 tee element and cutter element causes difficulty in attaching, operating and detaching the tapping tool. This problem is solved with a novel t-slot 9 articulating mechanism that allows the tapping tool to independently align to the tapping tee and align to the cutter. Thus, the tapping tool is easily 11 engaged or disengaged with both elements concurrently, and operates 12 smoothly in rotatably extending and retracting the cutter.
13 Turning now to the drawings, figures and features are identified as (XIX) 14 where the first X ident~es the figure, and the second X identifies the number on the figure.
18 As previously indicated, the present invention comprises four primary 17 components: a cap, a tee body, a cutter, and a tapping tool.
18 Cap (Figure 1) 19 1. The cap (111) is preferably made of polyethylene material, but any suitable metal or plastic material can be used for the cap. We prefer 21 polyethylene, especially HDPE, because of its performance and 22 manufacturing properties. We use high performance, stress-rated 23 polyethylene for its exceptional resistance to stress cracking, and its 24 acceptability to gas utility customers. PA11 or another suitable thermoplastic could also be used.
26 2. The purpose of the cap is to provide a permanent gas-tight seal at the 27 top of the tapping tee body. The top of the tapping tee body must be LCO/9T0 ~ Mt'I hOlLl3H~ 08~i~ ~16 SZB~ 8Z : ZT CC~'OZiZT
1 exposed during installation for access to the cutter. The cap and sealing 2 gasket are installed on the tee to provide the final, permanent gas-tight 3 seal. In certain standard non-M8B tapping tees, the cap is the primary 4 gas seal. In the present M9B design, a sealed cutter provides a primary . seal, thus the cap provides a secondary seal or back-up that is designed 6 as fully capable primary seal. Gas seal redundancy is a unique safety 7 feature provided by the present MBB design.
8 3. In the present invention, the seal between the top end of the tapping tee 9 tower and the underside of the cap is preferably effected with a flat, washer-shaped gasket (1l2), preferably of 50 durometer, Buna-N rubber 11 material. The inside skirt of the cap is threaded to mate with the 12 buttress thread on the top rim of the tapping tee tower. As the cap is 13 screwed down, the underside of the cap compresses the gasket against 14 the top of the tee, effecting a static seal. The seal is enhanced with a 16 series of inverted v-shaped ring projections on the gasket sealing 1fi surtace in the underside of the cap, and on the gasket sealing surtace at 17 the top end of the tapping tee tower. Other gasket materials such as 18 other rubbers, other elastomers or plastics, cork, etc., would also be 19 suitable, provided they are resistant to the tapping tee service environment, and are of comparable hardness and resilience. for our 21 cap gasket se2~l design, the hardness of the gasket material should be 22 from 40 to fi0 durometer, Shore D scale (per ASTM D 2240). Buna~n 23 rubber of 50 durometer hardness has been found to work best for gas 24 distribution.
4. A cap on a conventiional threaded-Cutter tapping tee provides the 26 primary seal against gas leakage. But with the MBB design, the primary 27 seal is the an the cutter, thus the cap provides a redundant, secondary 28 or back-up seal.
LCO/9T0~ M6'Z I~02i.1HH~ 086t~ CL8 SZ6~ BZ:ZT CCiOZiZT
1 5. Saddle fusion application tools clamp around the cap to hold the tee in 2 position far saddle fusion joining to a gas main pipe or the pipe to be 3 tapped into.
4 6. The mating threads of the tapping tee rim and the inside skirt of the cap are a buttress thread design. A buttress thread has one flat side and 6 one angled side as opposed to a conventional v-shaped thread where 7 both sides are angled. Compared to a typical v-shaped thread, the 8 buttress thread design provides superior resistance to thread 9 disengagement when a longitudinal tensile load is applied. This is because in tightening a v-thread the mating thread engagement 11 surtaces are at an angle to each other, and to the longitudinal tensile 12 force applied as the thread is tightened. The engagement angle causes 13 an outward farce that tends to make the external thread expand and 14 jump over the internal thread. But in the buttress thread design, the engagement surfaces are perpendicular to the tightening force, so there 1B is no propensity far the threads to jump or strip.
17 7. For a selected Standard Volume Tapping Tee (SVTT), the internal 1$ buttress thread is 1-5/$" diameter, with a pitch of 12 threads per inch;
for 19 a selected High Volume Tapping Tee (HVTT~, the buttress thread is 2-518" diameter with a pitch of 12 threads per inch. The number threads 21 per inch (or mm) can be more or less than 12 so long as the cap thread 22 and the tapping tool driving shaft thread have the same thread pitch.
23 For the tapping tool to screw onto the tee body during installation, the 24 thread on the tapping tool cutter driving shaft and the cap thread on the tee body must have the same pitch.
26 Tee Body 27 1. The tee body (211) is preferably made from polyethylene material. In the 28 present invention, we have found preferable to use high pertormance, LCO/LZOf~J M~'I I~O2L13H~ 08tfi CL6 SZ6$ 6Z:ZT CC:OZ/ZT
19 Further, the design of the present invention is independent of the means used to connect the tapping tee to the main. The Frialen and the Fusamatic 21 tapping tees are only electrofused to the main.
22 Various materials are currently employed for main lines, such as plastic, 23 particularly polyethylene. Another thermoplastic material, polyarnide 11, 24 PA11, (or nylon 11) is also sometimes used for gas pipe and fittings. The present invention preferably is used with polyethylene, especially High 26 Density Polyethylene (HDPE) but also may be used with other plastics, such 27 PA11.
LCO/bTO~ M~''I 1~O~I<1HH~ 08~D CL6 SZB.g. 8Z:ZT C~/OZ/Zi 1 As indicated above, the tapping tool of the present invention preferably 2 includes a novel articulating or self aligning feature. Although the cutter is in 3 the middle of the tapping tee, it does not need to be pertectly centered in the 4 tapping tee for the device to be fully functional. In the invention, however, the tapping tool detachably threads onto the tapping tee, and concurrently 6 detachably engages the cutter, therefore, misalignment between the tapping 7 tee element and cutter element causes difficulty in attaching, operating and detaching the tapping tool. This problem is solved with a novel t-slot 9 articulating mechanism that allows the tapping tool to independently align to the tapping tee and align to the cutter. Thus, the tapping tool is easily 11 engaged or disengaged with both elements concurrently, and operates 12 smoothly in rotatably extending and retracting the cutter.
13 Turning now to the drawings, figures and features are identified as (XIX) 14 where the first X ident~es the figure, and the second X identifies the number on the figure.
18 As previously indicated, the present invention comprises four primary 17 components: a cap, a tee body, a cutter, and a tapping tool.
18 Cap (Figure 1) 19 1. The cap (111) is preferably made of polyethylene material, but any suitable metal or plastic material can be used for the cap. We prefer 21 polyethylene, especially HDPE, because of its performance and 22 manufacturing properties. We use high performance, stress-rated 23 polyethylene for its exceptional resistance to stress cracking, and its 24 acceptability to gas utility customers. PA11 or another suitable thermoplastic could also be used.
26 2. The purpose of the cap is to provide a permanent gas-tight seal at the 27 top of the tapping tee body. The top of the tapping tee body must be LCO/9T0 ~ Mt'I hOlLl3H~ 08~i~ ~16 SZB~ 8Z : ZT CC~'OZiZT
1 exposed during installation for access to the cutter. The cap and sealing 2 gasket are installed on the tee to provide the final, permanent gas-tight 3 seal. In certain standard non-M8B tapping tees, the cap is the primary 4 gas seal. In the present M9B design, a sealed cutter provides a primary . seal, thus the cap provides a secondary seal or back-up that is designed 6 as fully capable primary seal. Gas seal redundancy is a unique safety 7 feature provided by the present MBB design.
8 3. In the present invention, the seal between the top end of the tapping tee 9 tower and the underside of the cap is preferably effected with a flat, washer-shaped gasket (1l2), preferably of 50 durometer, Buna-N rubber 11 material. The inside skirt of the cap is threaded to mate with the 12 buttress thread on the top rim of the tapping tee tower. As the cap is 13 screwed down, the underside of the cap compresses the gasket against 14 the top of the tee, effecting a static seal. The seal is enhanced with a 16 series of inverted v-shaped ring projections on the gasket sealing 1fi surtace in the underside of the cap, and on the gasket sealing surtace at 17 the top end of the tapping tee tower. Other gasket materials such as 18 other rubbers, other elastomers or plastics, cork, etc., would also be 19 suitable, provided they are resistant to the tapping tee service environment, and are of comparable hardness and resilience. for our 21 cap gasket se2~l design, the hardness of the gasket material should be 22 from 40 to fi0 durometer, Shore D scale (per ASTM D 2240). Buna~n 23 rubber of 50 durometer hardness has been found to work best for gas 24 distribution.
4. A cap on a conventiional threaded-Cutter tapping tee provides the 26 primary seal against gas leakage. But with the MBB design, the primary 27 seal is the an the cutter, thus the cap provides a redundant, secondary 28 or back-up seal.
LCO/9T0~ M6'Z I~02i.1HH~ 086t~ CL8 SZ6~ BZ:ZT CCiOZiZT
1 5. Saddle fusion application tools clamp around the cap to hold the tee in 2 position far saddle fusion joining to a gas main pipe or the pipe to be 3 tapped into.
4 6. The mating threads of the tapping tee rim and the inside skirt of the cap are a buttress thread design. A buttress thread has one flat side and 6 one angled side as opposed to a conventional v-shaped thread where 7 both sides are angled. Compared to a typical v-shaped thread, the 8 buttress thread design provides superior resistance to thread 9 disengagement when a longitudinal tensile load is applied. This is because in tightening a v-thread the mating thread engagement 11 surtaces are at an angle to each other, and to the longitudinal tensile 12 force applied as the thread is tightened. The engagement angle causes 13 an outward farce that tends to make the external thread expand and 14 jump over the internal thread. But in the buttress thread design, the engagement surfaces are perpendicular to the tightening force, so there 1B is no propensity far the threads to jump or strip.
17 7. For a selected Standard Volume Tapping Tee (SVTT), the internal 1$ buttress thread is 1-5/$" diameter, with a pitch of 12 threads per inch;
for 19 a selected High Volume Tapping Tee (HVTT~, the buttress thread is 2-518" diameter with a pitch of 12 threads per inch. The number threads 21 per inch (or mm) can be more or less than 12 so long as the cap thread 22 and the tapping tool driving shaft thread have the same thread pitch.
23 For the tapping tool to screw onto the tee body during installation, the 24 thread on the tapping tool cutter driving shaft and the cap thread on the tee body must have the same pitch.
26 Tee Body 27 1. The tee body (211) is preferably made from polyethylene material. In the 28 present invention, we have found preferable to use high pertormance, LCO/LZOf~J M~'I I~O2L13H~ 08tfi CL6 SZ6$ 6Z:ZT CC:OZ/ZT
-15-1 stress-rated polyethylene for its except~nal resistance to stress 2 cracking, and its acceptability to gas utility customers. PA11 or another 3 suitable thermoplastic could also be used. For heat fusion joining, the 4 tee body and the gas main pipe should be like materials, e.g., both PE
or both PA11.
5 2. The tapping tee body provides a se2~led conduit (114) for gas to 7 communicate between the main pipe and the service line pipe (117).
8 The tee body tower contains and guides the internal cutter (1l5) that is 9 used to penetrate the main pipe wall.
3. The tee body has a concave curved saddle base (116) for joining the tee 11 body to the side of a main pipe. Typically, the tee body attaches to the 12 top of the polyethylene main pipe, but the attachment could be on the 13 side, or the boifiom, or any locatson around the main pipe. The main 14 pipe also does not need to be horizontal. It can be vertical or at any angle between horizontal and vertical. Typically, the curved saddle base 1fi is joined to the main using hot plate saddle fusion, but the tee body may 17 be adapted with different saddle base configurations for joining to the 18 polyethylene main pipe side wall by electrofusion or mechanical means.
19 The mounting surtace of the saddle base is curved to match the curvature of the main pipe.
21 4. The tee body has a tubular tower (1!3 and 1!4) that extends directly up 22 from the curved saddle base (1l6), such that when the saddle base is 23 joined to the main pipe, the centerline of the tubular tower is oriented at 24 a right (90°) angle to the centerline of the main pipe. The top end of the tower has a gasket sealing surtace that is flat, except for a series of 26 circular, inverted v-shaped rib projections similar to the gasket seating 27 surface in the underside of the cap. The top outer rim of the tower is 28 threaded with a buttress thread for connecting to the cap or the tapping 29 tool. Below the buttress thread, the outside diameter increases to form LC0;8T0~ M~'I h02~,13H~ 08~t~ CL8 SZ6$ BZ:ZT CCiOZiZT
or both PA11.
5 2. The tapping tee body provides a se2~led conduit (114) for gas to 7 communicate between the main pipe and the service line pipe (117).
8 The tee body tower contains and guides the internal cutter (1l5) that is 9 used to penetrate the main pipe wall.
3. The tee body has a concave curved saddle base (116) for joining the tee 11 body to the side of a main pipe. Typically, the tee body attaches to the 12 top of the polyethylene main pipe, but the attachment could be on the 13 side, or the boifiom, or any locatson around the main pipe. The main 14 pipe also does not need to be horizontal. It can be vertical or at any angle between horizontal and vertical. Typically, the curved saddle base 1fi is joined to the main using hot plate saddle fusion, but the tee body may 17 be adapted with different saddle base configurations for joining to the 18 polyethylene main pipe side wall by electrofusion or mechanical means.
19 The mounting surtace of the saddle base is curved to match the curvature of the main pipe.
21 4. The tee body has a tubular tower (1!3 and 1!4) that extends directly up 22 from the curved saddle base (1l6), such that when the saddle base is 23 joined to the main pipe, the centerline of the tubular tower is oriented at 24 a right (90°) angle to the centerline of the main pipe. The top end of the tower has a gasket sealing surtace that is flat, except for a series of 26 circular, inverted v-shaped rib projections similar to the gasket seating 27 surface in the underside of the cap. The top outer rim of the tower is 28 threaded with a buttress thread for connecting to the cap or the tapping 29 tool. Below the buttress thread, the outside diameter increases to form LC0;8T0~ M~'I h02~,13H~ 08~t~ CL8 SZ6$ BZ:ZT CCiOZiZT
-16, 1 a step or stop ledge. The stop ledge provides a positive stop so the cap 2 or the tapping tool cannot be screwed down too far and over-tightened.
3 5. A tubular service outlet (1!7) connects to the side of the tower 4 immediately above the curved saddle base. The centerline of the service outlet tube is oriented at a right (90°) angle to the centerline of fi the tapping tee tower, and at a right (90°) angle to the centerline of the 7 main pipe. The outermost end of the service outlet is for connecting to 8 the service pipe. Typically, different outlet connection end styles and 9 sizes are offered including outlet end styles for joining to a service pipe by hot plate butt fusion, electrofusion, or mechanical means, or hot plate 11 socket fusion. Outlet end sizes vary generally from 112' CTS (16 mm) 12 through 2' IPS (fi3 mm), but could be smaller or larger. The cylindrical 13 bore of the service outlet opens without restriction into the cylindrical 14 bore of the tee body tower.
6. According to a preferred embodiment of the invention, the smooth tower 16 bore is provided with three progressively smaller diameters progressing
3 5. A tubular service outlet (1!7) connects to the side of the tower 4 immediately above the curved saddle base. The centerline of the service outlet tube is oriented at a right (90°) angle to the centerline of fi the tapping tee tower, and at a right (90°) angle to the centerline of the 7 main pipe. The outermost end of the service outlet is for connecting to 8 the service pipe. Typically, different outlet connection end styles and 9 sizes are offered including outlet end styles for joining to a service pipe by hot plate butt fusion, electrofusion, or mechanical means, or hot plate 11 socket fusion. Outlet end sizes vary generally from 112' CTS (16 mm) 12 through 2' IPS (fi3 mm), but could be smaller or larger. The cylindrical 13 bore of the service outlet opens without restriction into the cylindrical 14 bore of the tee body tower.
6. According to a preferred embodiment of the invention, the smooth tower 16 bore is provided with three progressively smaller diameters progressing
17 in location upwardly in the tower. Starting from the bottom of the tower,
18 where the tower attaches to the main line, the first diameter extends
19 upwardly to a point slightly above the topmost edge of the service outlet bore. The first diameter is sized to allow the cutter to pass without 21 compressing the ~-ring, thereby preventing damage to the O-ring during 22 cutter installation in manufacture. The second diameter progresses 23 upwardly above the first diameter to a point close to the top of the tower.
2~ The second diameter is sized to compress the O-ring on the cutter to effect a gas-tight seal. In the second diameter, the O-ring is 26 compressed. As explained in the Summary of the Invention above, the 27 O-ring is compressed preferably between 0.5 and 50 percent, more 28 preferably between 1 and 25 percent, and most preferably between 15 29 and 25 percent. A short tapered section between the first and second diameters provides a smooth transition to compress the O-ring without LC0;8T0~ ME''I I~02IA3H~ 081'fi CL8 SZB.gr 6Z:ZT CEiOZ~i.T
1 damage during cutter installation in manufacture. The third diameter 2 progresses upwardly immediately above the second diameter and to the 3 end of the tower. The third diameter is sized to allow unrestricted 4 passage so the tapping tool may engage the cutter, but to prevent any further upward movement of the cutter, thereby preventing cutter f expulsion due to pressurized gas or fluid from the main line below the ? cutter.
8 Cutter 9 1. The cutter (1/5 and 311) is preferably made of metal. Steel or stainless steel are preferably used for gas distribution piping, but appropriate 11 grades of aluminum or brass would also be suitable.
12 2. 'The purpose of the cutter is to perforate the wall of the main pipe, i.e., to 13 tap the main. It is rotatably forced into and through the wall of the main 14 pipe by turning the tapping tool handle. As described below under uTapping Tool", the tapping tool has threads along the outside wall (at 3 1fi in Figure 4),and these threads fit into threads on the inside bore of the 17 tapping tool, so that as the tapping tool handle is rotated, the tapping 't8 tool drives the cutter (5 in Figure 1} forward toward and then through the 19 sidewall of the main pipeline, so as to perforate or penetrate into the main pipeline. Once the perforation has been made, the tapping tee 21 handle is turned in the opposite direction to rotatably withdraw the cutter 22 and the section of main pipe wall (coupon) (219) cut from the main pipe.
23 As the cutter withdraws from the main pipe wall, pressurized gas from 24 the main pipe enters the bore of the tee tower, flows into the service outlet and into the service pipe. In the present MOB design, the cutter is 26 sealed with an O-ring (118) to prevent gas leakage past the cutter where 27 it would escape to the environment.
LCO/OZO~ M~'I h0?I~13H~ 086fi CL8 SZ8$~ 6Z~ZT CC/OZ/Zt 1 It may be noted that gas main tapping generally occurs in a small 2 excavation, or bell hole. In the bell hole, gas main pipe is exposed at 3 the bottom, but the excava~on is just large enough for the installer to 4 work. A belt hole is not necessarily considered a conned space per , OSHA standards because gas piping is generally from 9 to 5 feet below fi grade. However, gas leakage into a small excavation like a bell hole 7 can be hazardous. The present MBB design prevents leakage or $ blowby during installation, thus providing a safer working environment.
9 3. The cutter is generally cylindrical. At the bottom or cutting end, the cylinder is hollowed out (312) part way to form a thin tubular section.
11 The bottom edge of the thin tubular section is machined t4 a sharp 12 cutting edge (3l3). The purpose of the cutting edge and the thin tubular 13 section is to cut thorough the wall of the main pipe, and retain the 14 coupon removed from the main pipe wall. The depth of the hollow in the thin tubular section is designed to exceed the thickness of the main pipe 1B wall coupon, and any wall curvature. At the topmost end of the hollow 17 section, a small hole (314) is drilled through the thin tubular section wall 18 to vent any pressure build-up in the in the cavity above the coupon.
19 4. Near the opposite end of the cutter, the outside diameter is grooved for the O-ring seal (316).
21 ~. The top or driven end of the cutter has a hole part way into its end.
The 22 first part of the hole is square (317), followed by a smaller, threaded hole 23 (318). The square hole may also be a hexagon shape. The purpasE of 24 the square (or hex) hole is to receive the driving tip of the tapping tool.
The purpose of the smaller threaded hole is to receive the cutter tool 26 locking screw that secures the tapping tool to the cutter. The cutting 27 end cavity and the driven end hole do not communicate with each other, 28 thus preventing any passage of gas through the cutter itself.
LCO~TZO~ Md"I hOtiA~H~ 08~b CL8 SZ6$ OC:ZT CCiOZ~ZT
_19_ 1 Tapping Tool 2 1. 'The tapping toot is used in tapping the main by rotatably extending the 3 cutter. The tapping tool is also used in the present invention to retract 4 the cutter.
2. The tapping tool is an assembly of five primary parts: tapping tool cap 6 (411), body (4I2), drive screw (413), tee bar handle (414), and locking 7 screw (4J5). The two remaining parts are a snap ring (416) and a roll pin 8 (7110). The snap ring fits in a groove in the top of the thread bore in the 9 tool body to limit the upward travel of the too) drive screw. The roll pin secures the locking screw within the drive screw. All parts are metal.
11 The cap and body are brass, but other appropriate metals such as steel 12 or high strength aluminum are also suitable. The drive screw, tee bar 13 handle, and locking screw are steel alloy.
14 3. The cap (Figure 5) is located at the lower end of the tool assembly. It is generally cylindrical. A hole in the bottom end is internally threaded with 16 a buttress thread (511 ) so the cap can be screwed onto the top of the tee 17 tower. A smaller hole (5/2) goes completely through the center of the 18 cap to allow the end of the tool drive screw to pass through. The upper 19 end sides of the tapping tool cap are machined to form a tee-shaped section (513).
21 4. The tapping tool body (Figure 6) is a cylinder having a larger diameter 22 lower end (611) and a smaller diameter upper end (612). A hole having a 23 standard 12 threads per inch v-thread runs along the inside length of the 24 tool body (613). The same 12 threads per inch pitch is used for the tower cap buttress thread. The tapping tool body and the cap must 26 have the same thread pitch so the tapping tool can be secured to the 27 cutter, then screwed down onto the tee tower. However, the thread 28 pitch could be more or less than 12 threads per inch, provided the tool LCO/ZZO~ :N~'1 .1~O~Ll~Ia OBbb ~L8 SZ6~ 0~:Zi ~C!OZ/ZT
2~ The second diameter is sized to compress the O-ring on the cutter to effect a gas-tight seal. In the second diameter, the O-ring is 26 compressed. As explained in the Summary of the Invention above, the 27 O-ring is compressed preferably between 0.5 and 50 percent, more 28 preferably between 1 and 25 percent, and most preferably between 15 29 and 25 percent. A short tapered section between the first and second diameters provides a smooth transition to compress the O-ring without LC0;8T0~ ME''I I~02IA3H~ 081'fi CL8 SZB.gr 6Z:ZT CEiOZ~i.T
1 damage during cutter installation in manufacture. The third diameter 2 progresses upwardly immediately above the second diameter and to the 3 end of the tower. The third diameter is sized to allow unrestricted 4 passage so the tapping tool may engage the cutter, but to prevent any further upward movement of the cutter, thereby preventing cutter f expulsion due to pressurized gas or fluid from the main line below the ? cutter.
8 Cutter 9 1. The cutter (1/5 and 311) is preferably made of metal. Steel or stainless steel are preferably used for gas distribution piping, but appropriate 11 grades of aluminum or brass would also be suitable.
12 2. 'The purpose of the cutter is to perforate the wall of the main pipe, i.e., to 13 tap the main. It is rotatably forced into and through the wall of the main 14 pipe by turning the tapping tool handle. As described below under uTapping Tool", the tapping tool has threads along the outside wall (at 3 1fi in Figure 4),and these threads fit into threads on the inside bore of the 17 tapping tool, so that as the tapping tool handle is rotated, the tapping 't8 tool drives the cutter (5 in Figure 1} forward toward and then through the 19 sidewall of the main pipeline, so as to perforate or penetrate into the main pipeline. Once the perforation has been made, the tapping tee 21 handle is turned in the opposite direction to rotatably withdraw the cutter 22 and the section of main pipe wall (coupon) (219) cut from the main pipe.
23 As the cutter withdraws from the main pipe wall, pressurized gas from 24 the main pipe enters the bore of the tee tower, flows into the service outlet and into the service pipe. In the present MOB design, the cutter is 26 sealed with an O-ring (118) to prevent gas leakage past the cutter where 27 it would escape to the environment.
LCO/OZO~ M~'I h0?I~13H~ 086fi CL8 SZ8$~ 6Z~ZT CC/OZ/Zt 1 It may be noted that gas main tapping generally occurs in a small 2 excavation, or bell hole. In the bell hole, gas main pipe is exposed at 3 the bottom, but the excava~on is just large enough for the installer to 4 work. A belt hole is not necessarily considered a conned space per , OSHA standards because gas piping is generally from 9 to 5 feet below fi grade. However, gas leakage into a small excavation like a bell hole 7 can be hazardous. The present MBB design prevents leakage or $ blowby during installation, thus providing a safer working environment.
9 3. The cutter is generally cylindrical. At the bottom or cutting end, the cylinder is hollowed out (312) part way to form a thin tubular section.
11 The bottom edge of the thin tubular section is machined t4 a sharp 12 cutting edge (3l3). The purpose of the cutting edge and the thin tubular 13 section is to cut thorough the wall of the main pipe, and retain the 14 coupon removed from the main pipe wall. The depth of the hollow in the thin tubular section is designed to exceed the thickness of the main pipe 1B wall coupon, and any wall curvature. At the topmost end of the hollow 17 section, a small hole (314) is drilled through the thin tubular section wall 18 to vent any pressure build-up in the in the cavity above the coupon.
19 4. Near the opposite end of the cutter, the outside diameter is grooved for the O-ring seal (316).
21 ~. The top or driven end of the cutter has a hole part way into its end.
The 22 first part of the hole is square (317), followed by a smaller, threaded hole 23 (318). The square hole may also be a hexagon shape. The purpasE of 24 the square (or hex) hole is to receive the driving tip of the tapping tool.
The purpose of the smaller threaded hole is to receive the cutter tool 26 locking screw that secures the tapping tool to the cutter. The cutting 27 end cavity and the driven end hole do not communicate with each other, 28 thus preventing any passage of gas through the cutter itself.
LCO~TZO~ Md"I hOtiA~H~ 08~b CL8 SZ6$ OC:ZT CCiOZ~ZT
_19_ 1 Tapping Tool 2 1. 'The tapping toot is used in tapping the main by rotatably extending the 3 cutter. The tapping tool is also used in the present invention to retract 4 the cutter.
2. The tapping tool is an assembly of five primary parts: tapping tool cap 6 (411), body (4I2), drive screw (413), tee bar handle (414), and locking 7 screw (4J5). The two remaining parts are a snap ring (416) and a roll pin 8 (7110). The snap ring fits in a groove in the top of the thread bore in the 9 tool body to limit the upward travel of the too) drive screw. The roll pin secures the locking screw within the drive screw. All parts are metal.
11 The cap and body are brass, but other appropriate metals such as steel 12 or high strength aluminum are also suitable. The drive screw, tee bar 13 handle, and locking screw are steel alloy.
14 3. The cap (Figure 5) is located at the lower end of the tool assembly. It is generally cylindrical. A hole in the bottom end is internally threaded with 16 a buttress thread (511 ) so the cap can be screwed onto the top of the tee 17 tower. A smaller hole (5/2) goes completely through the center of the 18 cap to allow the end of the tool drive screw to pass through. The upper 19 end sides of the tapping tool cap are machined to form a tee-shaped section (513).
21 4. The tapping tool body (Figure 6) is a cylinder having a larger diameter 22 lower end (611) and a smaller diameter upper end (612). A hole having a 23 standard 12 threads per inch v-thread runs along the inside length of the 24 tool body (613). The same 12 threads per inch pitch is used for the tower cap buttress thread. The tapping tool body and the cap must 26 have the same thread pitch so the tapping tool can be secured to the 27 cutter, then screwed down onto the tee tower. However, the thread 28 pitch could be more or less than 12 threads per inch, provided the tool LCO/ZZO~ :N~'1 .1~O~Ll~Ia OBbb ~L8 SZ6~ 0~:Zi ~C!OZ/ZT
-20-1 body thread pitch and the towerlcap buttress thread pitch are the same.
2 The top inside edge of the threaded bore is grooved for a snap ring 3 (8/4}.
4 5. The driving screw is a hollow shaft. The bottom tap end is square (711 ) to engage into the square hole in the top of the cutter (317). Above the 6 square, the shaft is round (712), and extends to a threaded central 7 section (7!3}, then above that, a lesser diameter (714) extends to a knob 8 (7!5) at the top that is cross drilled (716) for the tee bar handle (717).
9 The hollow center (718) extends for the full length of the shaft, and is a diameter large enough for the locking screw (719). The threaded center 11 section (713) is a standard v-thread of the same size and pitch 12 (12 threads per inch) as the mating thread in the body. At a distance 13 between the threaded central part and the top knob, a hole (7/10) is 14 drilled through the shaft, but off-line to the shaft centerline. This hole receives a roll pin that secures the locking screw in the driving shaft_ 16 6. The tee bar handle (7!7) is a solid round rod that is cross drilled (7111) at 17 its midpoint. It fits through the hole in the top knob of the driving shaft.
18 The tee bar h2~ndle is used to manually rotate the driving shaft.
19 7. The lacking screw has a bottom portion that is threaded (7112) to mate with the threaded hole in the cutter (318). A knob (7113) at the top is
2 The top inside edge of the threaded bore is grooved for a snap ring 3 (8/4}.
4 5. The driving screw is a hollow shaft. The bottom tap end is square (711 ) to engage into the square hole in the top of the cutter (317). Above the 6 square, the shaft is round (712), and extends to a threaded central 7 section (7!3}, then above that, a lesser diameter (714) extends to a knob 8 (7!5) at the top that is cross drilled (716) for the tee bar handle (717).
9 The hollow center (718) extends for the full length of the shaft, and is a diameter large enough for the locking screw (719). The threaded center 11 section (713) is a standard v-thread of the same size and pitch 12 (12 threads per inch) as the mating thread in the body. At a distance 13 between the threaded central part and the top knob, a hole (7/10) is 14 drilled through the shaft, but off-line to the shaft centerline. This hole receives a roll pin that secures the locking screw in the driving shaft_ 16 6. The tee bar handle (7!7) is a solid round rod that is cross drilled (7111) at 17 its midpoint. It fits through the hole in the top knob of the driving shaft.
18 The tee bar h2~ndle is used to manually rotate the driving shaft.
19 7. The lacking screw has a bottom portion that is threaded (7112) to mate with the threaded hole in the cutter (318). A knob (7113) at the top is
21 knurled so the screw may be tamed by hand. Part way down the screw
22 shaft, the diameter is slightly reduced (7114). This area coincides with
23 the roll pin location in the driving shaft (7110) such that when the locking
24 screw is inserted into the hollow center of the driving shaft, and the roll pin installed, the locking screw cannot be pulled out, but can be rotated 26 within the driving shaft.
27 8. The tool is assembled in the following manner: the cap (Figure 5) slides 28 into the tee-slot in the bottom of the body (6~5), then the driving shaft is LCO~CZO~ M~''I 1~02I.1HH~ 06~~ C18 SZE$ OC:ZT CC%OZ;ZT
1 threaded into the body from the top, such that the square driving tip 2 passes through the center hole in the cap. When the driving screw is 3 turned well into the body, the snap ring is installed in the top of the body.
4 The tee bar handle is inserted through the driving shaft knob such that the hole in the tee bar handle is aligned with the hole through the driving 6 shaft. The threaded end of the locking screw is then inserted completely 7 through the driving shaft from the top, and the roll pin inserted through 8 the driving shaft. The assembly is illustrated in Figure 4. In this 9 manner, the parts are secured together in a single tool.
The Tapping Operation 11 Main pipe tapping is preferably accomplished in the following manner using a 12 preferred embodiment of a tapping tee in accordance with the present 13 invention:
14 1. The tapping tee of appropriate saddle connection design is attached to the side of the main pipe using saddle heat fusion, or electrofusion, or 1 fi mechanical means.
17 2. The service line pipe is connected to the tapping tee outlet by the 18 appropriate joining means (e.g., socket fusion, butt fusion, electrofusion, 7 9 or mechanical joint).
3. The tapping tee cap and gasket are removed.
21 4. The tapping tool drive screw is screwed down the tool body so that the 22 square drive end projects past the end of the tool cap about 112 to 23 314 inch. The tool is then positioned over the top of the tapping tee, and 24 the square drive engaged into the cutter. The tool locking screw is turned to screw it into the cutter. This secures the tapping tool driving 26 shaft to the cutter (2l13).
LCO:bZO~ M~''I h02t.13H~ OBi~fi CLB SZB~ TC:ZT C~:OZiZT
1 5. The tapping tool body is screwed down onto the tee tower buttress 2 thread until the tool cap contacts the tee tower stop ledge (2114).
3 6. The tee bar handle is rotated to advance the cutter to and through the 4 main pipe wall. When the wall is contacted, taming resistance increases sharply, then decreases by about half when the wall is completely 6 penetrated. Changes in turning torque identify cutter position to the 7 operator. For example, turning torque to advance the cutter in the tower 8 is about 112-2 ft-Ib. Torque increases to about 20-22 ft-Ib while cutting 9 through the pipe wall, and drops to about 10-12 ft-Ib when the wall is 1fl penetrated. If the operator ignores the reduced turning force, and 11 continues to advance the cutter, the advance will stop when the bottom 12 of the driving shaft threaded section contacts the top of the tool cap 13 (2110). The hole through the tool cap is smaller than the driving shaft 14 threaded section, and will not allow it to pass. When advanced to its maximum position, the cutter O-ring seal is still above the outlet hole in 16 the tapping tee (2111). Therefore, the cutter is sealed for the full length 17 of its advance.
18 7. The tee bar handle is then rotated in the opposite direction, which 19 retracts the cutter back up the tapping tee tower. As the cutter tip exits the main wall penetration, gas under pressure from the main pipe enters 21 the tapping tee body, and flows into the service line pipe. Retraction is 22 continued until rotation is stopped when the top of the driving shaft 23 threaded sectbn contacts the snap ring (2112).
24 $. The locking screw is then unscrewed from the cutter, and the tool unscrewed from the tapping tee buttress thread. The tool can then be 26 lifted off the tapping tee.
27 9. Finally, installing and hand tightening the gasket and cap provides a 28 secondary, duplicate seal against gas leakage.
LC0:9Z0~ M~''I I~0?L1~H~ OBfifi CLg SZ68. TC:ZT CC'4Z~ZT
2 Tanuino Tee Leak Testing 3 When tapping a pressurized gas main, it is important to minimize the amount 4 of gas that escapes past the cutter through the tappin8 tee tower. The following procedure was used to test for leakage between the tapping tee 6 cutter and tower when the tapping tee is installed on a pressurized main.
The 7 procedure described below allows different tapping tee devices to be 8 compared or, alternatively, allows the effectiveness of different sealing 9 components to be compared.
A pressured main pipeline is prepared by capping the ends of a length of 11 main pipe, then fitting one end cap to connect it to a regulated, compressed 12 gas supply. Any suitable supply of compressed gas such as air or nitrogen or 13 any suitable gas may be used. The main pipeline is then internally 14 pressurized to 0.69 Mega-Pascals (100 pounds per square inch} ar greater.
A tapping tee device as described in the present invention is securely 16 attached to the side of the pressurized main pipeline. The service line end of 17 the tapping tee can simply be capped for the purposes of this test. The 1$ removable tapping tool as described in this invention is engaged with the 19 cutter, and affixed to the top of the tapping tee. The tapping tool handle is then rotated to advance the cutter through the tapping tee, and cut an 21 aperture through the wall of the main pipe. The tapping tool handle is then 22 rotated in the opposite direction to retract the cutter from the pipe wall, and 23 bade to the top of the tapping tee. The tapping tool is then removed from the 24 top of the tapping tee, and disengaged ftom the cutter. The tapping tee device and internally pressurized main pipeline are then immersed in water.
26 A beaker or other container of known valume is submerged, filled with water, 27 then inverted over the top of the tapping flee device. Gas bubbles evolving 2$ from the top of the tapping tee are thus captured in the inverted container.
29 The total volume of gas captured during a time period, such as minutes or seconds, is measured and recorded.
LCO%9Z0~ M~''I H02I~1HH~ 08bi~ CLB SZE$ TC:ZT CC: OZiZT
1 Using the above procedure, tests of the tapping tee device es described in 2 this invention were conducted, with the following results:
Specimen Number Pressure in Main Test Result, leaks a in literslmin 744-99-1 1.03 MPs (154 psi) 0 744-99-3 1.03 MPs (150 psi) 0.12"
744-99-6 1.03 MPs {150 psi) 0 744-99-8 1.03 MPs 150 si 0 744-99-2 1.38 MPs (200 psi) 0 744-99-4 1.38 MPs (200 psi) 0 744-99-5 1.38 MPs (200 psi) 0 744-99-7 1.38 MPs 200 Si 0 3 *Damaged D-ring discovered in post-test examination.
4 Tapping tees with conventional, threaded cutter design were also tested using the same procedure, with the following results:
Specimen Number Pressure in Main Test Result, teaks a in literslmin 735-99-1 0.69 MPs (100 psi) 1,33 ?35-99-2 0.69 MPs (100 psi) 1.30 735-99-3 0.69 MPs (100 psi) 1.20 735-99-4 0.69 MPs (100 psi) 1.20 735-99-5 0.69 MPs (100 psi) 1.33 735-99-5 0.69 MPs 100 si 1.33 7 As seen from these examples, the tapping tee in accordance with the present 8 invention provided surprisingly high resistance andlor protection against 9 leakage of fluid from the main line through the tapping tee used to tap into the main line.
LCO/LZO~ M~''I I~0?L13H~ 08i~fi CL8 SZ6$ TC:ZT CC/OZiZT
27 8. The tool is assembled in the following manner: the cap (Figure 5) slides 28 into the tee-slot in the bottom of the body (6~5), then the driving shaft is LCO~CZO~ M~''I 1~02I.1HH~ 06~~ C18 SZE$ OC:ZT CC%OZ;ZT
1 threaded into the body from the top, such that the square driving tip 2 passes through the center hole in the cap. When the driving screw is 3 turned well into the body, the snap ring is installed in the top of the body.
4 The tee bar handle is inserted through the driving shaft knob such that the hole in the tee bar handle is aligned with the hole through the driving 6 shaft. The threaded end of the locking screw is then inserted completely 7 through the driving shaft from the top, and the roll pin inserted through 8 the driving shaft. The assembly is illustrated in Figure 4. In this 9 manner, the parts are secured together in a single tool.
The Tapping Operation 11 Main pipe tapping is preferably accomplished in the following manner using a 12 preferred embodiment of a tapping tee in accordance with the present 13 invention:
14 1. The tapping tee of appropriate saddle connection design is attached to the side of the main pipe using saddle heat fusion, or electrofusion, or 1 fi mechanical means.
17 2. The service line pipe is connected to the tapping tee outlet by the 18 appropriate joining means (e.g., socket fusion, butt fusion, electrofusion, 7 9 or mechanical joint).
3. The tapping tee cap and gasket are removed.
21 4. The tapping tool drive screw is screwed down the tool body so that the 22 square drive end projects past the end of the tool cap about 112 to 23 314 inch. The tool is then positioned over the top of the tapping tee, and 24 the square drive engaged into the cutter. The tool locking screw is turned to screw it into the cutter. This secures the tapping tool driving 26 shaft to the cutter (2l13).
LCO:bZO~ M~''I h02t.13H~ OBi~fi CLB SZB~ TC:ZT C~:OZiZT
1 5. The tapping tool body is screwed down onto the tee tower buttress 2 thread until the tool cap contacts the tee tower stop ledge (2114).
3 6. The tee bar handle is rotated to advance the cutter to and through the 4 main pipe wall. When the wall is contacted, taming resistance increases sharply, then decreases by about half when the wall is completely 6 penetrated. Changes in turning torque identify cutter position to the 7 operator. For example, turning torque to advance the cutter in the tower 8 is about 112-2 ft-Ib. Torque increases to about 20-22 ft-Ib while cutting 9 through the pipe wall, and drops to about 10-12 ft-Ib when the wall is 1fl penetrated. If the operator ignores the reduced turning force, and 11 continues to advance the cutter, the advance will stop when the bottom 12 of the driving shaft threaded section contacts the top of the tool cap 13 (2110). The hole through the tool cap is smaller than the driving shaft 14 threaded section, and will not allow it to pass. When advanced to its maximum position, the cutter O-ring seal is still above the outlet hole in 16 the tapping tee (2111). Therefore, the cutter is sealed for the full length 17 of its advance.
18 7. The tee bar handle is then rotated in the opposite direction, which 19 retracts the cutter back up the tapping tee tower. As the cutter tip exits the main wall penetration, gas under pressure from the main pipe enters 21 the tapping tee body, and flows into the service line pipe. Retraction is 22 continued until rotation is stopped when the top of the driving shaft 23 threaded sectbn contacts the snap ring (2112).
24 $. The locking screw is then unscrewed from the cutter, and the tool unscrewed from the tapping tee buttress thread. The tool can then be 26 lifted off the tapping tee.
27 9. Finally, installing and hand tightening the gasket and cap provides a 28 secondary, duplicate seal against gas leakage.
LC0:9Z0~ M~''I I~0?L1~H~ OBfifi CLg SZ68. TC:ZT CC'4Z~ZT
2 Tanuino Tee Leak Testing 3 When tapping a pressurized gas main, it is important to minimize the amount 4 of gas that escapes past the cutter through the tappin8 tee tower. The following procedure was used to test for leakage between the tapping tee 6 cutter and tower when the tapping tee is installed on a pressurized main.
The 7 procedure described below allows different tapping tee devices to be 8 compared or, alternatively, allows the effectiveness of different sealing 9 components to be compared.
A pressured main pipeline is prepared by capping the ends of a length of 11 main pipe, then fitting one end cap to connect it to a regulated, compressed 12 gas supply. Any suitable supply of compressed gas such as air or nitrogen or 13 any suitable gas may be used. The main pipeline is then internally 14 pressurized to 0.69 Mega-Pascals (100 pounds per square inch} ar greater.
A tapping tee device as described in the present invention is securely 16 attached to the side of the pressurized main pipeline. The service line end of 17 the tapping tee can simply be capped for the purposes of this test. The 1$ removable tapping tool as described in this invention is engaged with the 19 cutter, and affixed to the top of the tapping tee. The tapping tool handle is then rotated to advance the cutter through the tapping tee, and cut an 21 aperture through the wall of the main pipe. The tapping tool handle is then 22 rotated in the opposite direction to retract the cutter from the pipe wall, and 23 bade to the top of the tapping tee. The tapping tool is then removed from the 24 top of the tapping tee, and disengaged ftom the cutter. The tapping tee device and internally pressurized main pipeline are then immersed in water.
26 A beaker or other container of known valume is submerged, filled with water, 27 then inverted over the top of the tapping flee device. Gas bubbles evolving 2$ from the top of the tapping tee are thus captured in the inverted container.
29 The total volume of gas captured during a time period, such as minutes or seconds, is measured and recorded.
LCO%9Z0~ M~''I H02I~1HH~ 08bi~ CLB SZE$ TC:ZT CC: OZiZT
1 Using the above procedure, tests of the tapping tee device es described in 2 this invention were conducted, with the following results:
Specimen Number Pressure in Main Test Result, leaks a in literslmin 744-99-1 1.03 MPs (154 psi) 0 744-99-3 1.03 MPs (150 psi) 0.12"
744-99-6 1.03 MPs {150 psi) 0 744-99-8 1.03 MPs 150 si 0 744-99-2 1.38 MPs (200 psi) 0 744-99-4 1.38 MPs (200 psi) 0 744-99-5 1.38 MPs (200 psi) 0 744-99-7 1.38 MPs 200 Si 0 3 *Damaged D-ring discovered in post-test examination.
4 Tapping tees with conventional, threaded cutter design were also tested using the same procedure, with the following results:
Specimen Number Pressure in Main Test Result, teaks a in literslmin 735-99-1 0.69 MPs (100 psi) 1,33 ?35-99-2 0.69 MPs (100 psi) 1.30 735-99-3 0.69 MPs (100 psi) 1.20 735-99-4 0.69 MPs (100 psi) 1.20 735-99-5 0.69 MPs (100 psi) 1.33 735-99-5 0.69 MPs 100 si 1.33 7 As seen from these examples, the tapping tee in accordance with the present 8 invention provided surprisingly high resistance andlor protection against 9 leakage of fluid from the main line through the tapping tee used to tap into the main line.
LCO/LZO~ M~''I I~0?L13H~ 08i~fi CL8 SZ6$ TC:ZT CC/OZiZT
Claims (8)
1. A tapping tee comprising:
(a) tee-shaped structure having three cylindrical hollow sections for:
(1) allowing flow of fluid from the main line;
(2) allowing flow of fluid to a service line; and (3) allowing access of a tapping tool to a cutter means;
(b) unthreaded annular cutter means fitting in unthreaded section (1) of the tee-shaped structure; and (c) an O-ring mounted in an upper portion of the annular cutter means and forming a seal against an inside wall of section (3) of the tee-shaped structure.
(a) tee-shaped structure having three cylindrical hollow sections for:
(1) allowing flow of fluid from the main line;
(2) allowing flow of fluid to a service line; and (3) allowing access of a tapping tool to a cutter means;
(b) unthreaded annular cutter means fitting in unthreaded section (1) of the tee-shaped structure; and (c) an O-ring mounted in an upper portion of the annular cutter means and forming a seal against an inside wall of section (3) of the tee-shaped structure.
2. A tapping tee in accordance with Claim 1 wherein section (1) has an inner bare which is smooth throughout its operative length.
3. A tapping tee in accordance with Claim 1 wherein the compression of the O-ring against the inside wall of section (3) is between 0.5 2nd 50 percent.
4. A tapping tee in accordance with Claim 3 wherein the compression is between 1 and 25 percent.
5. A tapping tee in accordance with Claim 3 wherein the compression is between 15 and 25 percent.
8. A tapping tee apparatus assembly comprising:
(a) means for attaching the tee to a main tine;
(b) tee-shaped structure having three cylindrical hollow sections for:
(1 ) allowing flow of fluid from the main line;
(2) allowing flow of fluid to a service line; and (3) allowing access of a tapping tool to a cutter means;
(c) unthreaded annular cutter means fitting in unthreaded section (1) of the tee-shaped structure;
(d) an O-ring mounted in an upper portion of the annular cutter means and forming a seal against an inside wall of section (3) of the tee-shaped structure; and (e) a tapping tool mounted on section (3), which tool can drive the cutting means through the unthreaded section (3), past section {2), and through the main line, and which tool can then withdraw the cutting means from the main line back into section (3) to thereby allow fluid in the main line to flow into section (2).
(a) means for attaching the tee to a main tine;
(b) tee-shaped structure having three cylindrical hollow sections for:
(1 ) allowing flow of fluid from the main line;
(2) allowing flow of fluid to a service line; and (3) allowing access of a tapping tool to a cutter means;
(c) unthreaded annular cutter means fitting in unthreaded section (1) of the tee-shaped structure;
(d) an O-ring mounted in an upper portion of the annular cutter means and forming a seal against an inside wall of section (3) of the tee-shaped structure; and (e) a tapping tool mounted on section (3), which tool can drive the cutting means through the unthreaded section (3), past section {2), and through the main line, and which tool can then withdraw the cutting means from the main line back into section (3) to thereby allow fluid in the main line to flow into section (2).
7. A tapping tee apparatus assembly in accordance with Claim 6 wherein the assembly comprises:
(a) an elongated cylindrical tapping tool member adapted to connect to the cutter (3) and to drive the cutter through the main line;
(b) a tapping tool cap adapted to connect to the top of section (3) of the tee-shaped structure;
(c) a tapping tool body which fits above the tapping tool cap and contains inner threads;
(d) a threaded drive screw, which matches the inner threads of (c), and which is fitted onto a center part of the tapping tool, for rotatably driving the cutter (c) through the main line;
(e) a handle on the tapping tool member to allow rotation of the tapping tool member in said matching threads; and (f) means to fix the cylindrical tapping tool into place in the tapping tool assembly in a position for rotatably driving the cutter (c) through the main line.
(a) an elongated cylindrical tapping tool member adapted to connect to the cutter (3) and to drive the cutter through the main line;
(b) a tapping tool cap adapted to connect to the top of section (3) of the tee-shaped structure;
(c) a tapping tool body which fits above the tapping tool cap and contains inner threads;
(d) a threaded drive screw, which matches the inner threads of (c), and which is fitted onto a center part of the tapping tool, for rotatably driving the cutter (c) through the main line;
(e) a handle on the tapping tool member to allow rotation of the tapping tool member in said matching threads; and (f) means to fix the cylindrical tapping tool into place in the tapping tool assembly in a position for rotatably driving the cutter (c) through the main line.
8. A tapping tee apparatus assembly in accordance with Claim 7 wherein the tapping tool cap is cylindrical in shape, with a top having a central hole sized to receive the cylindrical tapping tool with at least a few thousands of an inch clearance around the cylindrical tapping tool, and wherein the top part of the tapping tool cap forms a tee shape by indentations along the cylindrical walls of the tapping tool cap, and wherein the tee shape is adapted to slot into a receiving portion of the tapping tool body.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17300899P | 1999-12-22 | 1999-12-22 | |
| US60/173008 | 1999-12-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2329392A1 true CA2329392A1 (en) | 2001-06-22 |
Family
ID=22630124
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2329392 Abandoned CA2329392A1 (en) | 1999-12-22 | 2000-12-21 | Tapping tee |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2329392A1 (en) |
-
2000
- 2000-12-21 CA CA 2329392 patent/CA2329392A1/en not_active Abandoned
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| Date | Code | Title | Description |
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| FZDE | Dead |