Trunnion Mounted Ball Valve

Short Description:

A trunnion ball valve has additional mechanical anchori […]

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Key Specifications / Features

A trunnion ball valve has additional mechanical anchoring of the ball at the top and the bottom, suitable for larger and higher pressure valves. The trunnion stem absorbs the thrust from the line pressure, preventing excess friction between the ball and seats, so even at full rated working pressure operating torque remains low.

Trunnion ball valves are manufactured with the features of double block and bleed (DBB), cavity relief, fire safe and secondary metal to metal seated etc.

Standard and Specifications:

Design and Manufacture API 6D
Wall Thickness API 6D
Face-to-Face Dimension API 6D
Flange End Dimension ANSI/ASME B16.5 (1” to 24”)
ANSI/ASME B16.47 (26” & up)
Butt-Weld End Dimension ANSI/ASME B16.25
Inspection & Testing API 6D/API 598
Fire Safe Design API 607/BS 6755
Material Nace MR 0175

Trunnion Ball Valve Design Features:

Double block and bleed

API 6D defines a double block and bleed valve as a “single valve with two seating surfaces that, in the closed position, provides a seal against pressure from both ends of the valve with a means of vending/bleeding the cavity between the seating surfaces.”

When the ball is in the closed position, each seat seals off the process medium independently at the same time between the up/down stream and body cavity; it allows bleeding of the trapped cavity pressure (DBB) through drain or vent valve. The double block and bleed function makes it possible to flush the valve under pressure and verify that the seats are sealing properly.

Self Cavity Relief

Trunnion ball valves constrain the ball by bearings. It is only allowed to rotate, but the ball seats can move. It also traps the media in the cavity when the operator closes the valve. It isolates the pipeline and the body cavity in the open and closed position. Thus, the pressure caught in the body cavity might be different from that in the line.  The pressure increases in the cavity when heated. It pushes the ball seat of the downstream side away from the ball by rising pressure against the spring load. When this happens, the pressure gets released.

Secondary Metal to Metal Seat Design

Standard seat design is primary soft seal, and secondary metal to metal seal. Seat insert is designed as pressed-in type which is easy for maintenance. Optional design with primary metal to metal seal and secondary soft seal seat design is also available upon request.

Double Piston Effect Seats-DIB 1 (Optional Upon request)

Medium pressure, both upstream and downstream as well as in the body cavity, creates a resultant thrust that pushes the seat rings against the ball. Valves with double piston effect seat rings require a cavity pressure relief device to reduce the build-up of over pressure in the body cavity.

Trunnion Ball Valve Drawings

 

Material Specifications

No. Name of Part A105/ENP LF2/F316 F316/F316
1 Nut A194 2H ASTM A194 7 ASTM A193 B8
2 Bolt A193 B7 ASTM A320 L7 ASTM A182 F316
3 Bonnet ASTM A105 ASTM A320 LF2 ASTM A182 F316
4 Gasket 304+Graphite 304+Graphite 304+Graphite
5 O-Ring Vion AED Vion AED Vion AED
6 O-Ring Vion AED Vion AED Vion AED
7 Graphite 304+Graphite 304+Graphite 304+Graphite
8 Spring Inconel X-750 Inconel X-750 Inconel X-750
9 Seat Ring ASTM A105 A182 F316 A182 F316
10 Pin Carbon Steel Stainless Steel Stainless Steel
11 Trunnion ASTM A105 A182 F316 A182 F316
12 Bearing Carbon Steel+Graphite Carbon Steel+Graphite Carbon Steel+Graphite
13 Gasket 304+Graphite 304+Graphite 304+Graphite
14 Ball ASTM A105+ENP A182 F316 A182 F316
15 Drain Plug Carbon Steel Stainless Steel Stainless Steel
16 Ring A105+ENP Stainless Steel Stainless Steel
17 Seal Ring Viton AED Stainless Steel Stainless Steel
18 Seat Ring PTFE, Nylon, PEEK PTFE, Nylon, PEEK PTFE, Nylon, PEEK
19 Feet Carbon Steel Carbon Steel Carbon Steel
20 Injection Valve Carbon Steel Stainless Steel Stainless Steel
21 Lifting Lug Carbon Steel Stainless Steel Stainless Steel
22 Body ASTM A105 A182 F316 A182 F316
23 Safety Valve Carbon Steel Carbon Steel Carbon Steel
24 Relief Valve Carbon Steel Stainless Steel Stainless Steel
25 Trunnion Bearing Carbon Steel+Graphite Carbon Steel+Graphite Carbon Steel+Graphite
26 Stem A182 F6A A182 F316 A182 F316
27 Key Carbon Steel Carbon Steel Carbon Steel
28 Thrust Washer PTFE PTFE PTFE
29 O-Ring Vion AED Vion AED Vion AED
30 Stuffing Box ASTM A105 ASTM A350 LF2 ASTM A193 B8
31 Bolt A193 B7 ASTM A320 L7 ASTM A193 B8
32 Packing 304+Graphite 304+Graphite 304+Graphite
33 Adapter ASTM A105 ASTM A105 A182 F316
34 Bolt A193 B7 ASTM A320 L7 ASTM A193 B8
35 Nut A194 2H ASTM A194 7 ASTM A194 8
36 Bolt A193 B7 ASTM A320 L7 ASTM A193 B8

Trunnion Ball Valve Dimensions-API 6D

ANSI Class 150 (Face to face in mm)

Size

RF BW RTJ
2” 178 216 191
3” 203 283 216
4” 229 305 241
6” 394 457 406
8” 457 521 470
10” 533 559 546
12” 610 635 622
14” 686 762 699
16” 762 838 775
18” 864 914 876
20” 914 991 927
24” 1067 1143

1080

 

ANSI Class 300 (Face to face in mm)

Size RF BW RTJ
2” 216 216 232
3” 283 283 298
4” 305 305 321
6” 403 457 419
8” 502 521 518
10” 568 559 584
12” 648 635 664
14” 762 762 778
16” 838 838 854
18” 914 914 930
20” 991 991 1010
24” 1143 1143 1165

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Tel: + 86-577-86373155, E-mail: export@reliavalve.com