Flanged & Bw Ends Forged Check Valve Class 900LBS - 1500LBS - 2500LBS Pressure Seal

CAST VALVE SERIES

 GATE VALVE

 GLOBE VALVE

 CHECK VALVE

 BALL VALVE

 BUTTERFLY VALVE

FORGED VALVE SERIES

 FORGED GATE VALVE

 FORGED GLOBE VALVE

 FORGED CHECK VALVE

INDUSTRIAL STRAINER SERIES

 Y TYPE STRAINER

 BASKET STRAINER

 T TYPE STRAINER

 TEMPORARY STRAINER

 FORGED STRAINER

 STRAINER SCREEN & BASKET

LATEST PRODUCTS

Pressure Seal Forged Check Valve Class 900LBS - 1500LBS - 2500LBS

Tengs Valve supplies high-quality Pressure Seal Bonnet (PSB) Forged Check Valves for ANSI Class 900Lbs, 1500Lbs and 2500Lbs, manufactured to BS 5352 standards. Available with integral flange, welded flange, and BW ends with RF or RTJ facing. Body materials include carbon steel, stainless steel, and duplex steel. Features Full Bore design with piston, lifting, and swing type disc. The PSB design uses internal line pressure to tighten the seal — becoming more reliable as pressure increases, making it the standard choice for Class 900 and above critical service. Ideal for high-pressure oil & gas, petrochemical, and power generation applications.

Specifications For Pressure Seal Forged Check Valve 900Lbs, 1500Lbs, 2500Lbs (Flanged, BW Ends)

• Design & Manufacture: BS 5352, API 602, ASME B16.34

• Constructions: Pressure Seal Bonnet (PSB)

• Bore Type: Full Bore / Full Port

• Valve Type: Piston, Lifting, Swing Type

• Size Range: 1/2″ to 2″ (DN15 to DN50)

• Pressure Ratings: ANSI 900LBS, 1500LBS, 2500LBS

• End Connections: Flanged (RF, RTJ), Butt Weld (BW)

• Flange Type: Integral Flange, Welded Flange

• Body Materials: A105, LF2, F5, F11, F22, F304, F316, F51, F53 or Equivalent

• Trim Materials: Various trim materials are available to suit different service conditions

• Sour Service: NACE MR 0175 on Request

• Test and Inspection: API 598

✓ Pressure Seal Bonnet design becomes tighter as internal pressure increases — ideal for Class 900 and above critical high-pressure service

Pressure Seal Bonnet (PSB) vs Bolted Bonnet (BB)

Parameter	Pressure Seal Bonnet (PSB)	Bolted Bonnet (BB)
Sealing Principle	Internal pressure pushes bonnet against body seal	Bolts compress gasket between bonnet and body
Pressure Range	Class 900 and above (recommended)	Class 150 to 900 (general service)
Sealing Reliability	Tighter as pressure increases	Constant sealing force
Weight	Heavier (PSB components + seal ring)	Lighter (bolts + gasket)
Maintenance	Requires depressurization for bonnet access	Easy bonnet access with bolts
Typical Application	HP steam, wellhead, gas injection, subsea	General hydrocarbon, process piping

Reference: BS 5352, ASME B16.34. PSB is the standard choice for Class 900 and above due to its self-energizing sealing principle.

Pressure Seal Forged Check Valve Material List

Part Name	Carbon Steel				Alloy Steel			Stainless Steel
	A105	A105	A105	LF2	F5	F11	F22	F304	F316	F51	F53
	Trim 1#	Trim 8#	Trim 5#	Trim 13Cr	Trim 13Cr	Trim 13Cr	Trim 13Cr	—	—	—	—
Body	A105	A105	A105	LF2	F5	F11	F22	F304	F316	F51	F53
Bonnet (PSB)	A105	A105	A105	LF2	F5	F11	F22	F304	F316	F51	F53
Disc	13Cr	13Cr	STL	13Cr	13Cr	13Cr	13Cr	F304	F316	F51	F53
Seat	13Cr	STL	STL	13Cr	13Cr	13Cr	13Cr	SS304	SS316	STL	STL
Hinge Pin	F6a	F6a	F6a	F6a	F6a	F6a	F6a	F304	F316	F51	F53
Seal Ring	Soft Iron	Soft Iron	Soft Iron	Soft Iron	Soft Iron	Soft Iron	Soft Iron	SS304	SS316	SS316	SS316
Gasket	RTJ Ring	RTJ Ring	RTJ Ring	RTJ Ring	RTJ Ring	RTJ Ring	RTJ Ring	RTJ Ring	RTJ Ring	RTJ Ring	RTJ Ring

Reference: BS 5352, API 602, ASTM A105, A350, A182. Materials may vary by model and pressure rating. Contact us for confirmed material certificate.

Forged Check Valve Class 900 - 1500LBS Pressure Seal Bonnet: Full Port

Item	Sub-item	1/2	3/4	1	1 1/4	1 1/2	2
Face to Face (mm)	L(RF) L1(BW)	216	229	254	280	305	268
Face to Face (mm)	L(RTJ)	216	229	254	280	305	371
Height (mm)	H	117	117	117	152	152	195
Flow Port (mm)	d	12	15	20	28	32	40
Weight (kgs)	—	10.5	11.9	13.9	19.9	26.9	32.5

Reference: BS 5352, ASME B16.10. Dimensions may vary by manufacturer. Contact us for confirmed drawing and quotation.

Forged Check Valve Class 2500LBS Pressure Seal Bonnet: Full Port

Item	Sub-item	1/2	3/4	1	1 1/4	1 1/2	2
Face to Face (mm)	L(RF) L1(BW)	264	273	308	349	384	450
Face to Face (mm)	L(RTJ)	264	273	308	352	387	454
Height (mm)	H	117	117	117	152	152	195
Flow Port (mm)	d	12	15	20	28	32	40
Weight (kgs)	—	12.6	14.9	16.5	24.8	30	35

Reference: BS 5352, ASME B16.10. Dimensions may vary by manufacturer. Contact us for confirmed drawing and quotation.

Pressure Seal Forged Check Valve Class 900 - 2500 Applications

• Oil and Gas Industry: High-pressure wellhead equipment, Christmas trees, manifold and flowline backflow protection.

• Power Generation: Main steam isolation, boiler drains, turbine bypass lines at Class 900 to 2500.

• Petrochemical: Hydrocracking, hydrotreating, catalytic cracking, reformer units.

• Subsea and Offshore: Subsea manifolds, HIPPS systems, high-pressure process lines.

• Gas Injection and Compression: Natural gas compressor lines, gas injection wells.

• Instrumentation: High-pressure instrument root valves, sensing line isolation.

FAQ - Pressure Seal Forged Check Valve Class 900 - 2500LBS

Q1: What is a Pressure Seal Bonnet (PSB) and how does it work?

A: Pressure Seal Bonnet uses internal line pressure to tighten the seal between the bonnet and body. A soft iron or stainless steel seal ring sits between the bonnet and body; as line pressure increases, it pushes the bonnet upward against the seal ring, compressing it and making the seal tighter. This self-energizing principle makes PSB more reliable than bolted bonnet at very high pressure and temperature, and it is the standard choice for Class 900 and above.

Q2: Why is PSB preferred for Class 900 and above?

A: At Class 900 and above, bolted bonnet designs require extremely heavy flanges and large bolts to maintain sealing force, which increases weight and cost. PSB uses the line pressure itself to maintain the seal, eliminating the need for massive bolting. This makes PSB more compact and reliable at high pressure. For Class 2500 (430 bar / 6,250 psi), PSB is essentially the only practical bonnet design.

Q3: What is the weight difference between PSB and BB designs?

A: PSB valves are generally heavier than BB valves of the same size and class because of the seal ring and thicker bonnet structure. For example, a 1/2 inch Class 900 PSB forged check valve weighs 10.5 kg, while the equivalent BB design weighs approximately 5.2 kg. However, PSB provides superior sealing reliability at high pressure, making the extra weight acceptable for critical service.

Q4: What is the difference between Class 900, 1500 and 2500 PSB forged check valves?

A: Class 900 PSB (153 bar / 2,220 psi) is suitable for high-pressure steam and gas transmission. Class 1500 PSB (260 bar / 3,750 psi) is designed for wellhead, gas injection, and high-pressure process service. Class 2500 PSB (430 bar / 6,250 psi) handles HP steam generators and gas compressor lines. Higher classes have thicker wall sections, heavier flanges, and longer face-to-face dimensions. For example, a 1/2 inch PSB valve has L(RF) of 216 mm in Class 900/1500 and 264 mm in Class 2500.

Q5: Why is PSB typically used with RTJ ends?

A: RTJ (Ring Type Joint) uses a metal ring gasket in a machined groove, providing superior sealing integrity under high pressure. PSB and RTJ are both designed for high-pressure critical service, making them a natural combination. For Class 900 and above, RTJ is the recommended flange facing. RF (Raised Face) is also available for less critical applications where the pressure is lower or maintenance access is more important.

Q6: Can PSB forged check valves be repaired or maintained?

A: PSB design requires depressurization before bonnet access. Once depressurized, the bonnet can be removed by releasing the seal ring, and internal trim (disc, seat, hinge pin) can be inspected or replaced. Because PSB relies on line pressure for sealing, it does not require periodic bolt torque checks like BB designs. This makes PSB lower maintenance in long-term service, though bonnet removal is more involved than BB. For critical service, we recommend stocking spare seal rings and trim parts.