GB2081406A - Pipes and pipe joints - Google Patents
Pipes and pipe joints Download PDFInfo
- Publication number
- GB2081406A GB2081406A GB8111500A GB8111500A GB2081406A GB 2081406 A GB2081406 A GB 2081406A GB 8111500 A GB8111500 A GB 8111500A GB 8111500 A GB8111500 A GB 8111500A GB 2081406 A GB2081406 A GB 2081406A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pipe
- sealing ring
- spigot end
- spigot
- diameter
- 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.)
- Granted
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L47/00—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics
- F16L47/06—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics with sleeve or socket formed by or in the pipe end
- F16L47/08—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics with sleeve or socket formed by or in the pipe end with sealing rings arranged between the outer surface of one pipe end and the inner surface of the sleeve or socket, the sealing rings being placed previously in the sleeve or socket
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Joints With Sleeves (AREA)
Abstract
A joint between first and second pipes 1, 2 of plastics material comprising a spigot end 3 of circular cross- section on the pipe 1 inserted into a socket end 4 of circular cross-section of the pipe 2 and a resilient sealing ring 10 carried in a circumferential groove 9 in the spigot end 3. The groove 9 is located in a first portion 7 of the spigot end 3 which has an external surface 8 which is convexly arcuately curved in the axial direction of the spigot end 3. The spigot end 3 also has second and third portions 5 and 6 which are joined integrally with the first portion 7 and are disposed on axially opposite sides of the latter. Each of the spigot end portions 5 and 6 has a diameter which reduces in the direction away from the portion 7, and the maximum diameter D1 of the portion 7 is less than the internal diameter D2 of the socket end 4, in the region of the latter which is engaged by the sealing ring 10, by an amount not exceeding one tenth of the maximum thickness d of the sealing ring 10 measured in the radial direction of the latter when in its relaxed state. <IMAGE>
Description
SPECIFICATION
Pipes and pipe joints
This invention is concerned with the joining together, end-to-end, of pipes of plastics material, in particular glass fibre-reinforced plastics (g.r.p.) material.
It is known to effect a joint between two pipes by inserting a spigot end of a first pipe into a socket end of a second pipe, a resilient sealing ring, for example of rubber or other elastomeric material, being provided in a circumferential groove formed in the spigot end of the first pipe. In a joint effected in this way, said sealing ring provides a fluid-tight seal between the walls of its groove, on the one hand, and the inner surface of the socket end of the second pipe, on the other hand.
When laying a pipe line employing spigot-andsocket type joints of the kind described above, in order to maintain the integrity of the joints, allowance has to be made for the fact that, along some sections, the pipe line may have to follow a curved path and that, after laying, the original alignment, or original inclination, between axes of adjacent pipes may become changed due to settlement or subsidence of the ground in which, or on which, the pipe line is laid. Such allowance is at present made by providing an annular gap of sufficient radial width between the external surface of the socket end of one pipe and the internal surface of the socket end of the other pipe with which the first mentioned pipe is joined.The present custom is to dimension this annular gap so that an angular deviation can be tolerated between the axes of adjacent pipes without the fluid-tightness of the joint between the pipes being adversely affected.
While joints of the kind just described are well suited for use in situations where settlement or subsidence may occur after laying of a pipe line, they have the disadvantage that the aforementioned wide annular gap increases the risk of the resilient sealing ring being forced at least partly out of its groove, especially when there is a high pressure differential across the sealing ring (for example a high internal pressure in the pipe line compared with the external pressure, or a high pressure surrounding the pipe line compared with the pressure in the pipe line).
Such partial forcing of the sealing ring out of its groove can damage the ring, which can lead to leakage at the pipe joint.
In one of its aspects, the present invention aims to provide a spigot-and socket type of pipe joint which does not have the disadvantage mentioned above.
According to this aspect of the invention, in a joint between first and second pipes of plastics material comprising a spigot end of circular cross-section on the first pipe inserted into a socket end of circular cross-section on the second pipe and a resilient sealing ring carried in a circumferential groove in said spigot end, said groove is located in a first portion of the spigot end of the first pipe which is convexly arcuately curved in the axial direction of the spigot end, said spigot end has second and third portions joined integrally with the first portion and disposed respectively axially outside and axially inside the first portion, each of said second and third portions of the spigot end having a diameter which reduces in the direction away from said first portion, and the maximum diameter of said first portion of the spigot end is less than the internal diameter of said socket end, in the region of the latter which is engaged by said resilient sealing ring, by an amount not exceeding one tenth of the maximum thickness of said resilient sealing ring measured in the radial direction of the sealing ring when in its relaxed state.
Due to the shapes of the first, second and third portions of the spigot end, the two pipes connected by a joint in accordance with the invention may have an angular deviation between the axes of the spigot and socket ends of as much as 5 degrees, or even more, without either pipe end being distorted and consequently damaged, or leakage occurring. At the same time, the radial width of the annular gap between the external surface of the first portion of the spigot end and the confronting internal surface of the socket end, at least in the region where said sealing ring is situated, is sufficiently small to remove practically all risk of the sealing ring being forced even partially out of its groove due to a pressure differential across the ring.
Preferably, the internal surface of the socket end of said second pipe is substantially circular cylindrical, at least in the region where it is engaged by said sealing ring. Axially outwardly of this region, the socket end of the second pipe may be flared outwardly.
In cases where a pipe line comprising joints in accordance with the invention is used in situations in which a low or medium pressure differential exists across the sealing rings of the joints, the sealing ring groove of each joint may be located substantially mid-way between the axially inner and outer ends of said first portion of the spigot end. In cases where the pipe line is used in situations in which a high pressure differential exists across the sealing rings of the joints, the sealing ring groove of each joint is preferably located nearer to that axial end of said first portion of the spigot end which is closer to the region of higher pressure.
The joint in accordance with the invention is particularly suitable for employment with pipes made of any g.r.p. material, with or without filler material, for example sand. The glass fibres may be present in the form of wound strand, woven mat or chopped fibres, or any combinations of these.
The joint in accordance with the invention is particularly suitable for use with pipes having an internal diameter of from 50 mm to 5 mm and a wall thickness of from 2.5 mm (for small diameter pipes) to 40 mm (for large diameter pipes).
According to a further aspect of the invention, in a pipe of plastics material, and in particular of g.r.p.
material, having a spigot end of circular crosssection at one end, a socket end of circular crosssection at the other end, and a resilient sealing ring mounted in a circumferential groove in said spigot end, said groove is located in a first portion of the spigot end which is convexly arcuately curved in the axial direction of the spigot end, said spigot end has second and third portions joined integrally with the first portion and disposed respectively axially outside and axially inside the first portion, each of said second and third portions of the spigot end has a diameter which reduces in the direction away from said first portion, and the maximum diameter of said first portion of the spigot end is less than the internal diameter of said socket end, in the region of the latter which, when the socket end is engaged with the spigot end of a second identical pipe, is engaged by the sealing ring of said second pipe, by an amount not exceeding one tenth of the maximum thickness of said resilient sealing ring measured in the radial direction of the sealing ring when it its relaxed state.
The invention will now be described, by way of example, with reference to the accompanying drawing, the single Figure of which is a sectional view through a pipe joint in accordance with the invention.
The drawing shows two pipes 1 and 2 of g.r.p.
material joined together by insertion of the spigot end 3 of the pipe 1 into the socket end 4 of the pipe 2.
The spigot end 3 has an axially inner end portion 5, an axially outer end portion 6, and an intermediate portion 7 integrally joined with the portions 5 and 6.
The spigot end portion 5 has a diameter which increases in the direction towards the axially outer end of the pipe 1 and the spigot end portion 6 has a diameter which increases in the direction away from the axially outer end of the pipe 1. The intermediate spigot end portion 7 has an external surface 8 which is arcuately convexly curved in the axial direction of the pipe 1. A circumferential groove 9 is formed in the spigot end portion 7 for the reception of a sealing ring 10 of rubber or other elastomeric material. In the example shown, the groove 9 is located substantially mid-way between the ends of the spigot end portion 7, but if desired this groove may be located nearer to either of the spigot end portions 5 and 6.
In its relaxed state the resilient sealing ring 10 is of circular cross-section, as indicated by the chain line 10a, having a maximum thickness, measured in the radial direction of the ring, of d. In the assembled joint, the ring 10 becomes compressed between the bottom of the groove 9 and the portion 11 of substantially circular cylindrical shape of the internal surface of the socket end 4 of the pipe 2, and assumes the flattened cross-sectional shape shown in full lines in the drawing. In order to faciliate insertion of the spigot end 3 into the socket end 4, lubricant may be applied to the internal surface of the socket end 4 and to the ring 10. The spigot end 3 is thereafter aligned with the socket end 4 and moved into the latter to complete the joint.Movement of the spigot end 3 into the socket end 4 may be accomplished using a hand lever on pipes of small size, or using appropriate power-assisted devices on pipes of large size.
In the example shown in the drawing, the maximum diameter of the spigot end portion 7 is D1, the internal diameter of the socket end surface portion 11 is D2 and the diameter of the bottom of the groove 9 is D3. The joint in accordance with the invention requires that D2 - D1 must not exceed 0.1 d. It is preferred that the sealing ring 10 should not be compressed, in the assembled joint, to less than half the maximum radial thickness of the ring in its relaxed state, i.e. to less than 0.5d in the embodiment illustrated. In other words, it is preferred that
D2 - D3 should not be less than d, and advantageously D2 - D3 lies in the range of from dto 1.8d.
In the example shown, the arcuately curved surface 8 has a radius of curvature approximately equal to 0.5D1. This radius of curvature may lie between 0.3D1 and D,.
The spigot end 2 and the socket end 4 may be formed integrally with the pipes 1 and 2, respectively. Alternatively, they may be moulded or mandrelwound as separate units which are subsequently secured, for example with an adhesive, to the pipes.
Claims (13)
1. A pipe of plastics material having a spigot end of circular cross-section at one end, a socket end of circular cross-section at the other end, and a resilient sealing ring mounted in a circumferential groove in said spigot end, in which said groove is located in a first portion of the spigot end which is convexly arcuately curved in the axial direction of the spigot end, said spigot end has second and third portions joined integrally with the first portion and disposed respectively axially outside and axially inside the first portion, each of said second and third portions of the spigot has a diameter which reduces in the direction away from said first portion, and the maximum diameter of said first portion of the spigot end is less than the internal diameter of said socket end, in the region of the latter which, when the socket end is engaged with the spigot end of a second identical pipe, is engaged by the sealing ring of said second pipe, by an amount not exceeding one tenth of the maximum thickness of said resilient sealing ring measured in the radial direction of the sealing ring when in its relaxed state.
2. A pipe according to claim 1, in which the internal surface of said socket end is substantially circular cylindrical, at least in the region of the socket end which, when the socket end is engaged with the spigot end of a second identical pipe, is engaged by the sealing ring of said second pipe.
3. A pipe according to claim 1 or 2, in which the arcuately curved first portion of said spigot end has a radius of curvature between 0.3 D1 and Do, where Ds, is the maximum diameter of said first portion of the spigot end.
4. A pipe according to claim 3, in which said radius of curvature is approximately equal to 0.5 D1.
5. A pipe according to any of the preceding claims, in which said spigot end and said socket end are formed integrally with the pipe.
6. A pipe according to any of claims 1 to 4, in which said spigot end and said socket end are formed as units separate from the pipe and then subsequently secured to the pipe.
7. A pipe according to any of the preceding claims, in which the pipe is made of glass fibrereinforced plastics material.
8. A pipe according to any of the preceding
claims, having an internal diameter of from 50 mm
to 5 m and a wall thickness of from 2.5 mm to 40
mm.
9. A pipe according to claim 1, constructed and
arranged substantially as herein described with
reference to, and as illustrated in, the accompanying
drawing.
10. A joint between first and second pipes of
plastics material comprising a spigot end of circular
cross-section on the first pipe inserted into a socket
end of circular cross-section on the second pipe and
a resilient sealing ring carried in a circumferential
groove in said spigot end, in which said groove is
located in a first portion of the spigot end of the first
pipe which is convexly arcuately curved in the axial
direction of the spigot end, said spigot end has second and third portions joined integrally with the
first portion and disposed respectively axially out
side and axially inside the first portion, each of said
second and third portions of the spigot end having a
diameter which reduces in the direction away from
said first portion, and the maximum diameter of said
first portion of the spigot end is less than the internal
diameter of said socket end, in the region of the
latter which is engaged by said resilient sealing ring,
by an amount not exceeding one tenth of the
maximum thickness of said resilient sealing ring
measured in the radial direction of the sealing ring
when in its relaxed state.
11. A joint according to claim 10, in which said
resilient sealing ring is compressed between the
radially inner surface of said groove and the internal
surface of said socket end to a radial thickness not
less than half the maximum thickness d of said resilient sealing ring measured in the radial direction
of the sealing ring when in its relaxed state.
12. A joint according to claim 11, in which the
diameter D3 of the radially inner surface of said
groove and the diameter D2 of the region of the
internal surface of said socket end which is engaged
by the resilient sealing ring are chosen so that D2 - D3
lies in the range of from d to 1.8d.
13. A joint between first and second pipes of
plastics material, constructed and arranged substan
tially as herein described with reference to, and as
illustrated in, the accompanying drawing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8111500A GB2081406B (en) | 1980-04-17 | 1981-04-13 | Pipes and pipe joints |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8012680 | 1980-04-17 | ||
| GB8111500A GB2081406B (en) | 1980-04-17 | 1981-04-13 | Pipes and pipe joints |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2081406A true GB2081406A (en) | 1982-02-17 |
| GB2081406B GB2081406B (en) | 1983-12-07 |
Family
ID=26275207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8111500A Expired GB2081406B (en) | 1980-04-17 | 1981-04-13 | Pipes and pipe joints |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2081406B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2218166A (en) * | 1988-04-20 | 1989-11-08 | Victaulic Plc | Jacking pipe seals |
| DE19743183A1 (en) * | 1997-09-30 | 1999-04-22 | Uponor Anger Gmbh | Pipe coupling with second pipe with insertion end |
| DE19751361A1 (en) * | 1997-11-20 | 1999-05-27 | Itt Mfg Enterprises Inc | Connection element for pipes or hoses |
| DE19949880A1 (en) * | 1999-10-15 | 2001-04-19 | Fischer Georg Rohrleitung | Arrangement to seal pipelines; has rotationally symmetrical flexible seal arranged in groove in wall of inner pipeline facing outer pipeline, having sealing areas joined by connection area |
| CN104329525A (en) * | 2014-11-08 | 2015-02-04 | 湖南潇湘源科技开发有限责任公司 | Glass fiber reinforced plastics pipeline sealing sleeve connector and a machining method thereof |
| US10808844B2 (en) | 2017-02-06 | 2020-10-20 | North American Pipe Corporation | System, method and apparatus for pipe restrained joint seal and lock |
| CN112460347A (en) * | 2020-12-25 | 2021-03-09 | 程思哲 | Single-groove pipeline interface capable of independently testing pressure |
-
1981
- 1981-04-13 GB GB8111500A patent/GB2081406B/en not_active Expired
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2218166A (en) * | 1988-04-20 | 1989-11-08 | Victaulic Plc | Jacking pipe seals |
| GB2218166B (en) * | 1988-04-20 | 1992-03-18 | Victaulic Plc | Jacking pipe seals |
| DE19743183A1 (en) * | 1997-09-30 | 1999-04-22 | Uponor Anger Gmbh | Pipe coupling with second pipe with insertion end |
| DE19743183B4 (en) * | 1997-09-30 | 2009-04-30 | Maincor Anger Gmbh | Combination coupling for providing stepless angular positions between pipes |
| DE19751361A1 (en) * | 1997-11-20 | 1999-05-27 | Itt Mfg Enterprises Inc | Connection element for pipes or hoses |
| US6199915B1 (en) | 1997-11-20 | 2001-03-13 | Itt Manufacturing Enterprises, Inc. | Connector element for tubing or hoses |
| DE19949880A1 (en) * | 1999-10-15 | 2001-04-19 | Fischer Georg Rohrleitung | Arrangement to seal pipelines; has rotationally symmetrical flexible seal arranged in groove in wall of inner pipeline facing outer pipeline, having sealing areas joined by connection area |
| DE19949880B4 (en) * | 1999-10-15 | 2007-02-22 | Georg Fischer Rohrleitungssysteme Ag | Arrangement for sealing pipelines |
| CN104329525A (en) * | 2014-11-08 | 2015-02-04 | 湖南潇湘源科技开发有限责任公司 | Glass fiber reinforced plastics pipeline sealing sleeve connector and a machining method thereof |
| CN104329525B (en) * | 2014-11-08 | 2016-01-13 | 湖南潇湘源科技开发有限责任公司 | Fiber reinforced plastic pipe seal sleeve interface and processing method thereof |
| US10808844B2 (en) | 2017-02-06 | 2020-10-20 | North American Pipe Corporation | System, method and apparatus for pipe restrained joint seal and lock |
| CN112460347A (en) * | 2020-12-25 | 2021-03-09 | 程思哲 | Single-groove pipeline interface capable of independently testing pressure |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2081406B (en) | 1983-12-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Effective date: 20010412 |