RU2334149C2 - Ball cock - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: ball cock incorporates a one-piece body with inlet and outlet branch pipes, a supported rotary ball plug and two seats spring-thrusted against the plug. Every seat is furnished with a polyurethane O-ring fitted in the holder and a holder with holes feeding lubricant, a sealant compound, into the gap between the plug and seat. The said seat is provided with a pressure ring and a protective metal ring, the latter being arranged in a cage fitted in a dead annular groove with holes receiving springs and with lock screws, to contact with plug ball surface. The pressure ring is furnished with holes for it to be fastened in the O-ring holder with a flange and a step. The said flange is furnished with the holes receiving the springs thrusting the seat against the plug. The aforesaid protective metal ring is made from strip and arranged between the holder through hole and the holes feeding sealant compound to the plug.

EFFECT: higher tightness, longer life, lower consumption of sealant compound.

2 cl, 7 dwg

Description

The invention relates to valves, in particular to ball valves for gas pipelines and process pipelines.

The quality of ball valves during operation is evaluated by the reliability of the tightness of the plug relative to the seats and the amount of sealant introduced into the valve to restore the tightness of the plug relative to the seats.

The reliability of the crane for tightness of the plug relative to the seats depends on the parameters of the working medium transported through the crane, the design of the saddle and the life of the crane. The well-known standard of OAO Gazprom is OTS-ZRA-98 “General Technical Specification. Shut-off and control valves, DN 100-1400 mm, PN from 6.4 to 42.0 MPa. " This standard is recommended for non-aggressive natural gas with mechanical impurities up to 10 mg / nm ³ , working medium temperature T ° C from -10 to +80 and should provide: tightness of the plug with saddles from 0.1 MPa to 1.1 PN (Section 4.6 .5), preliminary preloading of saddles by means of springs (section 4.6.3.), Supply of grease - sealant to the plug (sections 4.6.14 and 4.6.15), various material designs of o-rings (sections 4.6. 17-4.6.19) and a crane service life of at least 30 years (Clause 10.1) with a service life of at least 4000 cycles for DN 100-200 mm, at least 2000 cycles for DN 300-1000 mm, at least 500 cycles for DN 1200-1400 mm (Clause 10.2).

The amount of sealant and the frequency of its introduction into the tap to restore the tightness of the plug relative to the seat depends on the size of the valve according to DN, the gap between the plug and the seat and the mode of operation of the tap (the number of turns of the plug in the tap per day, month, year). According to the data of OOO Yamburggazdobycha OAO Gazprom, the consumption rate of sealant (paste type 131-129C grade 2 or SAG-type 2 according to TU38.401-58-289-01) is one press-on for valves DN 50-100 mm - 0.5 kg, DN 150-300 mm - 1.0 kg, DN 400-500 mm - 1.5 kg, DN 700 mm - 2 kg, DN 1000 mm - 3 kg. The average frequency of pressurizing the sealant into the tap is 3.3 times a year, and the annual consumption of sealant at LLC Yamburggazdobycha exceeds 14400 kg.

The sealant, when the plug is turned, is blown by the gas flow into the gas pipeline, pollutes the gas and leads to large penalties for the sale of dirty gas.

Known ball valve according to British patent GB 1414440, F16K 5/06, F16K 5/20, F16K 5/22 F16K 5/00 from 11/19/1975 (1).

The crane is designed to provide a seal between the housing and the ball surface of the swivel on the tube supports. The valve comprises a one-piece (welded) body with inlet and outlet nozzles 10 having channels 66 for supplying a liquid tight seal to the seats 56 or 56 and 56a and to the surface of the ball plug 13. To provide a seal, the plugs relative to the seat body contain a clip 56 of one or two parts 56 and 56a, sealing 72 and protective 81 nylon rings, synthetic rubber seal 73, channels 77 for supplying a liquid tight seal to zone 76 to the ball surface of the plug 13. The seats 56 are pressed against the plug 13 by the springs 64 .

The disadvantages of the known design of a ball valve are:

- when the tube is turned, the mechanical impurities of the passing gas are held by a synthetic rubber seal 73, when the tube is rotated, the sealing ring 72 and the protective ring 81 are destroyed, which leads to a violation of the seat tightness with respect to the tube;

- taps of this design did not find practical application in the USSR until 1988 (see D.F. Gurevich, O.N. Zarinsky, Yu.K. Kuzmin, Armature Handbook for gas and oil pipelines. - L., Nedra, 1988, Table 3.3, p. 114).

Known ball valve by A.S. No. 1654622 A1, F16K 5/06 dated June 7, 1991 (2). The crane is designed to increase reliability by ensuring a constant fit of the protective ring to the surface of the ball plug.

The ball valve contains a housing 1 with a spherical stopper 2 and a two-chamber seat (chambers A and B) in the form of two coaxially mounted bushings 3 and 4 with a sealing ring 5 in the outer sleeve 3 and a protective ring 6 placed in the annular groove 7 of the inner sleeve 4. Sealing the polyurethane ring 5 is pressed against the plug 2 and protected from mechanical impurities of the passing gas by a protective metal ring 6. The ring 6 is rigidly fixed from axial movement relative to the ring 4 by the retaining ring 8, but has the possibility of radial movement δ value relative to the plug 2 due to elastic deformations of the wall in the zone of the annular groove 14 or cut rings: protective 6, retaining 8 and pressure 9. There are no channels for lubricating the sealing ring 5.

The well-known ball valve removed from the previous valve a synthetic rubber seal 73, a liquid-tight seal lubricant and grease channels 66 and 77, a protective tape 68, a spring 64 and replaced the material of the protective ring 6 (81) from nylon to metal, which reduced the number of settled mechanical impurities in the zone of the plug and the seat between the sealing ring 5 and the protective ring 6 when turning the plug. The coefficient of friction of mechanical impurities on the metal (cork 2 and the protective ring 6) is much less than on synthetic rubber and nylon.

The disadvantages of the known design of a ball valve is the following:

- there are no springs for clamping the sealing ring 5 to the plug; paragraph 4.6.3 of the OTC - ZRA-98 is not provided;

- there are no channels for supplying lubricant to the o-ring 5 when it is destroyed by mechanical impurities in the passing gas when the plug is turned, paragraphs 4.6.14, 4.6.15 OTS - ZRA-98 are not provided;

- the protective ring 6 is fixed in the inner sleeve 4 motionless retaining ring 8 and moves away from the tube together with the inner sleeve 4;

- when the valve is in the closed position in the outlet, in chamber B, there is no gas pressure, the protective ring 6 is radially compressed, moves away from the plug and the reliability of the ball valve is impaired;

- the execution of the protective ring 6 cut increases the accumulation of mechanical impurities of the passing gas in the gap between the plug 2 and the rings 5 and 6 when the valve is open;

- a crane of this design has not found practical application in Russia (see Pipe fittings for the gas industry. Catalog, TsIINTIKHIMNEFTEMASH, M., 1987, p. 2 and 4, where p. 2 - Yu.L. Rukhlov - author of the patent, p. 4 - saddle design other than patent).

Known ball valve according to the patent of Russia No. 2059137 C1, F16K 5/06, 5/22 from 04/07/1996 (3). The crane contains a housing, a rotary plug with a passage channel, two seats with sealing elements and a ring installed in the housing, in contact with the plug and forming a cavity for lubrication and providing additional sealing when applying lubricant.

The crane according to patent No. 2059137 is a prototype of the proposed crane.

Significant disadvantages of the known design are:

- in the design of the saddle there is no protective ring, which leads to the accumulation of mechanical impurities in the gap between the stopper and the seat when the valve is open and when the stopper is turned, the seal polyurethane ring is destroyed and the valve is not tight;

- when the plug is rotated, the lubricant from the gap between the plug 3, the seat 6 and the ring 8 above the sealing ring 7 is blown with gas into the housing 1 and the effect of additional sealing of the valve with grease disappears;

- the springs for pressing the saddle to the plug when the grease-sealant is pressed into the valve with a pressure P> P _y stop working, which confirms the absence of a callout on the spring in figure 2 and the link for its purpose in the patent description;

- the technical solution is used only in necessary cases (accidents and other situations), and not when operating the crane before repair;

- the volume of chamber A with gaps and channels from the sealing ring 7 to the ring 5 for filling with grease-sealant significantly exceeds the volume of zone 76 of the patent - analogue (1).

The technical task of the invention is to improve the quality of the valve by tightness of the plug in the valve body, increase the life of the crane before repair and reduce the consumption of sealant during operation of the crane.

The technical problem is solved due to the fact that in a ball valve containing an integral body with inlet and outlet nozzles, a rotary ball plug on supports and two saddles pressed by springs to the plug, each of which contains a polyurethane sealing ring fixed in a holder, a holder with holes for supplying sealant to the gap between the plug and the cage, the seat is equipped with a clamping ring and a protective metal ring in contact with the ball surface of the cork and installed in the cage in a blind annular groove with holes under the springs and retaining screws, the clamping ring is made with holes for fixing in the holder of the sealing ring, and the holder is made with a flange and a ledge, and the holes for the saddle clamping spring to the plug are made in the flange, and the protective metal ring is closed from sheet metal and is located between cage bore and holes for the sealant to the cork, and the protective metal ring is made of rolled brass, or aluminum alloys, or stainless steel and contains a flat shaft grooves for locking screws and ends of various shapes, of which one end in contact with the stopper is made conical with an angle of 45 ° from the outer diameter to the inside, and the other end, pressing the protective ring to the stopper by means of springs, is made straight and with lead-in grooves, located in the region of the holes of the holder for supplying the sealant, while in the holder the holes for supplying the sealant along the length of the annular groove are made of increased diameter while maintaining the cross-sectional area of the holes for the passage of the sealant.

The proposed ball valve and seat are shown schematically in the drawings.

Figure 1 shows a General view of the crane in the open position, where

DN - bore diameter of the valve,

D _Tr - inner (passage) diameter of the welded pipe,

P _y - conditional pressure in MPa and the direction of gas movement.

Figure 2 shows the design of the saddle along section I of figure 1 in taps on P _at over 10 MPa, where

Z is the gap between the plug and seat,

D _upl - the estimated diameter of the contact of the sealing polyurethane ring with the stopper,

l _upl - the seal width of the plug sealant,

d is the diameter of the hole in the cage for the supply of grease-sealant to the tube,

DN - bore diameter of the crane (saddle cage).

In Fig.3 - the design of the saddle in section II of Fig.1 for holding the protective ring in the cage with locking screws.

In Fig.4 - the design of the saddle along section I of Fig.1 for cranes on P _at up to 10 MPa.

In Fig.5 - the shape of one and the other ends of the protective spring-loaded metal ring, in Fig.2.

Figure 6 - design of a protective spring-loaded metal ring in figure 3 with a closed flat oval groove for the locking screws.

In Fig.7 - the shape of the other end of the protective spring-loaded metal ring, in Fig.4.

Ball valve (see figure 1) contains a one-piece housing 1 with input 2 and output 3 nozzles; rotary ball plug 4 on supports, two saddles 5, pressed by springs to the plug and installed in nozzles 2 and 3 with the possibility of interaction with the surface of the ball plug 4 to seal it; spindle 6 for connecting the plug 4 with a drive for turning the plug (not shown), a support 7 for installing a crane and welding to the pipes 8.

The valve has a bore diameter DN equal to the inner (bore) diameter of the welded pipe d _tr , which eliminates water loss when the gas passes through the valve under pressure Р _у and allows the cleaning and diagnostic equipment to pass through the valve.

Each seat (see FIGS. 2 and 3) contains a polyurethane sealing ring 9, a clamping ring 10, a clip 11, springs 12 for pressing the saddle to the plug 4, a piston ring 15, a protective rubber ring 16, a movable protective metal ring 17, a spring 18 , screws 19 and locking screws 20.

The clamping ring 10 is made with holes for fixing the sealing polyurethane ring 9 in the holder 11 with screws 19 and provides a gap Z between the plug 4 and the clamping ring 10.

The holder 11 is made with a flange 13 and with a ledge 14 under the limiter of the reverse stroke of the saddle; with through holes in the flange above the ledge 14 under the spring 12 of the clamp seat to the tube; with holes with a diameter of "d" for the supply of sealant in the gap between the plug and seat on the width of the seal l _upl. ; with a blind annular groove with holes, for the protective metal ring 17 and springs 18, located between the passage bore of the DN holder and the holes with a diameter of "d" for supplying sealant in taps on Р _у over 10 MPa (see Fig. 2) and for holes larger with a diameter of "d ₁ " for the supply of sealant in cranes on P _at up to 10 MPa (see figure 4) and with radial threaded holes for the locking screws 20 (see figure 3).

Protective metal closed movable ring relative to the cage ring 17 (see figure 2 and figure 3) is made of sheet metal materials depending on the purpose of the cranes for the aggressiveness of the working environment: brass, or aluminum alloys, or stainless steel and contains ends of various shapes. One end face 23 (see FIG. 5) in contact with the stopper is tapered with an angle of 45 ° from the outer diameter to the inside, and the other end 24, pressing the protective ring 17 or 22 against the stopper 4 by means of springs 18 (see FIG. 2 and Fig. 4), made straight (see Fig. 5) and with input inclined slots 26 (see Fig. 7) in the portions of the holes for supplying sealant in taps on P _at up to 10 MPa (see Fig. 4). To hold the protective ring 17 or 22 in the holder with locking screws 20 (see Fig. 3), blind flat-oval grooves 25 are made in the protective rings (see Fig. 5).

Ball valve works as follows.

The ball valve in the open position (see figure 1) performs a function similar to the welded pipes 8 when passing the transported gas along the inner diameter DN of the pipes 2 and 3, seats 5 and tube 4 with a pressure P _у . The tightness of the plug 4 in the nozzles 2 and 3 is provided by the saddles 5, pressed against the plug 4 by the springs 12 and the pressure forces P _y in the area of the ring 15 relative to D _{upl of the} sealing polyurethane ring 9 (see _figure 2). The tightness of the plug 4 is ensured by a polyurethane sealing ring 9, partially a sealant with a width of l _upl and a protective spring-loaded metal ring 17 or 22 pressed against the plug 4 by the springs 18. The protective spring-loaded metal ring 17 or 22 protects the gap Z between the plug 4 and the seat 5 from getting into him various items from the pipeline.

When the plug 4 is turned by the spindle 6, the spring-loaded protective metal ring 17 or 22 is pressed by the springs 18 to the plug 4, is held by the locking screws 20 in the ferrule 11 upon loss of contact with the plug 4 and holds the sealant on the ferrule 11 at a width of l _up to rotation of the plug 4 by 90 ° .

The gas to be transported, when the plug 4 is rotated, blows the sealant from the section l _off half of the seal length D _{off the} saddle 5 of the inlet pipe 2 in a swirl flow when it hits the ball surface of the plug. The mass (volume) of the blown sealant for the saddle 5 of the inlet pipe 2:

where G is the mass (volume) of the blown sealant, kg;

D _upl - diameter, tube seal length, mm;

l _upl - tube seal width, mm;

Z is the gap between the seat and the plug, mm;

γ is the specific gravity of the lubricant (sealant), kg / mm ³ .

The replenishment of the sealant blown out by gas when the plug 4 is rotated in volume is limited by a protective spring-loaded metal ring 17 or 22, determined by formula (1) and significantly less than the existing sealant consumption rates. The volume of sealant blown out of the outlet pipe is significantly less than from the inlet pipe.

An example of a specific implementation.

Under the conditions of OJSC Volgogradneftemash, a ball valve DN 300 mm at P _at 8.0 MPa for non-aggressive gas was manufactured and tested for strength and tightness.

In a commercially available valve, the saddle 5 seals the plug 4 by D _уп = = 327 mm, the holes for supplying sealant with a diameter of d = 4 mm are located on a circle with a diameter of 308 mm, and 18 compression springs 12 for pressing the saddle 5 to the plug 4 are located in blind holes with a depth of 14 +0.43 mm of nozzles 2 and 3. The springs are applied in 2 classes, 2 categories according to GOST 13764-86 with a tolerance of ± 1.1 mm along the length of the free state.

In the proposed crane in the ferrule 11 of the saddle 5 with a diameter of 308 mm a blind ring groove was made with a width of 3.8 mm and a depth of 14 mm (see figure 4). At the end of the annular groove, 12 holes were drilled with a diameter of 3.8 mm and a depth of 5 mm under the springs 18 (see figure 2). The protective ring 22 was made of 3.0 mm thick brass sheet, inserted into the annular groove (see Fig. 4) and fixed from falling out of the annular groove of the yoke 11 with three retaining screws 20 (see Fig. 3). In the holder 11, pre-drilled holes d from a diameter of 4 mm to d _{1 with a} diameter of 6 mm to a depth of 17 mm, ensuring equal areas for the passage of the sealant to the plug 4 (see figure 4). In this case, the protective ring 22 had the shape of one end 23 - conical with an angle of 45 ° from the outer diameter to the inner, and the other end 24 - a straight line (see figure 5). Under the locking screws 20 with a diameter of 5 mm, three blind flat oval grooves 25 were made with a width of 5 mm and a length of 1 = 8 mm (see Fig. 6), with a gap of Z = 2 mm between the seat 5 and the plug 4 (see Fig. 2) . At the second end of the protective ring 22, in the area of the holes d ₁ = 6 mm, inlet slope slots 26 were made with a width of 8 mm (see Fig. 7) for the sealant to enter from the holes d ₁ to the plug 4 into the section l _upl (see Fig. .four).

The holder 11 was made with a flange 13 and a ledge 14 for stop in the end face 21 of the pipe 2 or 3 (see figure 2 and 3). In the flange 13 above the step 14, through holes were drilled for the compression springs 12, which were transferred from the nozzles 2 and 3 to the seat 5. The existing compression springs 12 with a free length of 28 ± 1.1 mm were sorted according to the free length tolerance and ground with a tolerance of ± 0 , 2 mm. Set and centered compression springs 12 with parallel polished ends in the through holes of the cage 11 with emphasis on the clamping ring 10 of the saddle 5 and the end face 21 of the pipe 2 (see figure 2 and 3). The springs 12 were compressed from a free length of 28 ± 0.2 mm to a working length of 23 mm, providing equal force to each spring 12 to press the seat 5 against the plug 4. When assembling the crane, the springs 12 were additionally compressed by 3 mm, from 23 mm to 20 mm, eliminating the compression of the springs 12 to the contact of the coils. This was achieved by withdrawing the saddle 5 from the plug 4 to the end face 14 of the holder 11 in the end face 21 of the pipe 2 (see figure 3). The length of the compression springs 12 to the contact of the turns is 17.6 mm The proposed installation and operation of compression springs 12 provided uniform pressure of the sealing polyurethane ring 9 of the seat 5 to the plug 4 at low pressure, up to 0.1 MPa.

Manufactured cranes No. 2305 and No. 2796 were tested at the factory for strength and tightness and ensured the tightness of the plug in the valve in class A GOST9544-93, and the crane head. No. 2305 was tested on November 9, 2006 at the stand of OAO Gazprom at Saratovorgdiagnostika LLC for cyclicality, sealant consumption and was recommended for distribution to all sizes of cranes manufactured at OAO Volgogradneftemash.

The positive effect of the proposed design of the ball valve seat.

Protective spring-loaded metal ring:

- protects the gap Z between the plug and the seat from solid objects from the pipeline getting into it during crane operation and early wear of the sealing ring;

- increases the life of the valve until the wear of the o-ring is complete by Z;

- protects against the penetration of the sealant from the gap Z between the stopper and the seat into the valve when pressing the sealant of the normalized volume;

- reduces the volume of the sealant when pressing into the valve to the calculated volume according to the formula (1), in the proposed valve from 1 kg to 0.1 kg;

- reduces gas pollution by sealant up to 10 times.

The saddle ensures tightness of the plug at low pressure up to 0.1 MPa due to the placement of springs in the through holes of the flange of the cage, their use with high accuracy along the length, which ensures uniform compression of all springs to clamp the saddle to the plug.

The proposed seat design simple to implement, during operation, and may find application in the taps DN 200-1400 mm R _y from 6.4 to 20.0 MPa for UTS-ZRA-98 of "Gazprom".

Claims (2)

1. A ball valve containing an integral body with inlet and outlet nozzles, a ball rotary plug on supports and two saddles pressed by springs to the plug, each of which contains a polyurethane sealing ring fixed in a holder, a holder with holes for supplying lubricant - sealant to the gap between a stopper and a clip, characterized in that the saddle is provided with a clamping ring and a protective metal ring in contact with the ball surface of the stopper and mounted in a clip in a blind ring groove with holes for springs and with supporting screws, the clamping ring is made with holes for fixing the sealing ring in the holder, and the holder is made with a flange and a ledge, and the holes for the saddle clamp spring to the stopper are made in the flange, and the protective metal ring is closed from sheet metal and is located between the hole of the holder and holes for supplying sealant to the plug. 2. Ball valve according to claim 1, characterized in that the protective metal ring is made of sheet metal of brass, or aluminum alloys, or stainless steel and contains flat oval grooves for locking screws and ends of various shapes, of which one end is in contact with the stopper, made conical with an angle of 45 ° from the outer diameter to the inside, and the other end, pressing the protective ring to the cork by means of springs, is made straight and with lead-in grooves located in the area of the holes of the holder for supplying sealant, while in the holder from the holes for supplying the sealant along the length of the annular groove are made of increased diameter while maintaining the cross-sectional area of the holes for the passage of the sealant.

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