Forged Check Valve 900LBS - 1500LBS - 2500LBS (Pressure Seal Bonnet)

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

PSB Forged Check Valve 900LBS - 1500LBS - 2500LBS - SW, NPT Ends

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 Socket Weld (SW), Threaded (NPT/Screwed) ends, sizes from NPS 1/2″ to NPS 2″ with Full Bore or Reduced Bore options. Valve types include Piston and Swing Type. Body materials include forged carbon steel (A105, LF2), alloy steel (F5, F11, F22), stainless steel (F304, F316), and duplex steel (F51). The Pressure Self-Sealing Bonnet 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.

Forged Steel Check Valve 900LBS - 1500LBS - 2500LBS (Pressure Seal Bonnet)

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

• Constructions: Pressure Self-Sealing Bonnet (PSB)

• Bore Type: Full Bore, Reduced Bore

• Valve Type: Piston Type, Swing Type

• Size Range: 1/2″ to 2″ (NPS 1/2 to NPS 2)

• Pressure Ratings: ANSI 900LB, 1500LB & 2500LB

• End Connections: Socket Weld (SW), Threaded (NPT/Screwed)

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

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

• Seat Type: Hard Seat (Metal Seat)

• Sour Service: NACE MR 0175 on Request

• Test and Inspection: API 598

✓ PSB + SW/NPT — the ideal combination for high-pressure small-bore instrument and sampling lines requiring compact installation and zero leakage

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

Parameter	PSB	BB	WB
Sealing Principle	Internal pressure self-energizing	Bolts + gasket	Seal welded to body
Leak Tightness	Best at high pressure	Good	Excellent
Maintenance	Depressurize for access	Easy trim replacement	Not repairable
Weight	Heaviest	Larger	Compact
Recommended Class	900–2500	150–900	600–1500
Typical Application	HP steam, wellhead, subsea	General service	Permanent installation

Reference: BS 5352, API 602. PSB is the standard choice for Class 900 and above; BB and WB are preferred for lower pressure classes with SW/NPT ends.

Socket Weld (SW) vs Threaded (NPT) Ends for PSB Valves

Parameter	Socket Weld (SW)	Threaded (NPT)
Connection Type	Welded (socket)	Threaded (screwed)
Standard	ANSI B16.11	ANSI B1.20.1
Leak Tightness	Excellent (welded joint)	Good (sealant required)
Pressure Limit	Full Class 900/1500/2500	Reduced at high temperature
Installation	Requires welding on site	Quick installation without welding
PSB Compatibility	Fully compatible with PSB	Fully compatible with PSB
Typical Application	Permanent Class 2500 HP service	Instrument lines, sampling, temporary connections

Reference: ANSI B16.11, ANSI B1.20.1. For Class 2500 PSB service, SW is strongly recommended over NPT due to the extreme pressure rating and the need for zero leakage.

Piston vs Swing Type PSB Forged Check Valve

Type	Disc Movement	Installation	Typical Application
Piston Type	Piston moves along flow axis	Horizontal or vertical upward flow	HP small-bore service, fast closing, tight sealing
Swing Type	Disc swings on hinge pin	Horizontal (recommended)	Lower pressure drop, NPS 1.5 to 2 sizes

Reference: BS 5352, API 602. Piston type is the most common for Class 900/1500/2500 PSB valves with SW/NPT ends; Swing type is available for Class 900/1500 in larger sizes (NPS 1.5 to 2).

PSB Forged Check Valve 900LBS - 2500LBS Material List

Part Name	Carbon Steel				Alloy Steel			Stainless Steel
	A105	A105	A105	LF2	F5	F11	F22	F304	F316	F51
	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
Bonnet (PSB)	A105	A105	A105	LF2	F5	F11	F22	F304	F316	F51
Disc	13Cr	13Cr	STL	13Cr	13Cr	13Cr	13Cr	F304	F316	F51
Seat	13Cr	STL	STL	13Cr	13Cr	13Cr	13Cr	SS304	SS316	STL
Hinge Pin	F6a	F6a	F6a	F6a	F6a	F6a	F6a	F304	F316	F51
Seal Ring	Soft Iron	Soft Iron	Soft Iron	Soft Iron	Soft Iron	Soft Iron	Soft Iron	SS304	SS316	SS316

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

PSB Forged Check Valve 900LBS - 1500LBS Dimensions (SW, NPT Ends)

Reference: BS 5352, ASME B16.11, ANSI B1.20.1. Dimensions may vary by manufacturer. Contact us for confirmed drawing and quotation.

PSB Forged Check Valve 2500LBS Dimensions (SW, NPT Ends)

Reference: BS 5352, ASME B16.11, ANSI B1.20.1. Dimensions may vary by manufacturer. Contact us for confirmed drawing and quotation.

PSB Forged Check Valve 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 - PSB Forged Check Valve 900LBS - 1500LBS - 2500LBS

Q1: What is a Pressure Self-Sealing Bonnet (PSB) and why is it used for Class 900+?

A: Pressure Seal Bonnet uses internal line pressure to self-energize 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 against the seal ring, tightening the seal. This self-energizing principle makes PSB more reliable than bolted bonnet at very high pressure, and it eliminates the need for massive bolting and heavy flanges. For Class 900 and above, PSB is the standard choice. At Class 2500 (430 bar / 6,250 psi), PSB is essentially the only practical bonnet design.

Q2: Why combine PSB with SW/NPT ends instead of flanged ends?

A: PSB is used for high-pressure service, and SW/NPT ends are used for small-bore (NPS 1/2 to NPS 2) compact installations. Combining PSB with SW/NPT creates an ultra-compact, high-pressure, zero-leakage valve that is ideal for instrument lines, sampling systems, and subsea manifolds where space is limited and leak tightness is critical. Flanged ends would add significant weight and require more space. PSB + SW/NPT is the most compact solution for Class 900 to 2500 small-bore high-pressure service.

Q3: What is the difference between Class 900, 1500 and 2500 PSB 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, gas compressor lines, and subsea HIPPS systems. Higher classes have thicker wall sections, heavier body and bonnet, and higher weight. For Class 2500, only SW ends (or BW with flanged connection) are recommended; NPT may not maintain full pressure rating at high temperature.

Q4: Can PSB 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 the 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. However, bonnet removal is more involved than BB. For critical service, we recommend stocking spare seal rings and trim parts. For Class 2500 subsea service, valves are typically replaced rather than repaired in situ.

Q5: What is the difference between SW and NPT ends for PSB valves?

A: SW (Socket Weld) ends are welded to the pipe, providing excellent leak tightness and full Class 900/1500/2500 pressure capability. NPT (Threaded) ends are screwed onto the pipe, allowing quick assembly and disassembly without welding — preferred for instrument lines and sampling systems. For Class 2500 PSB valves, SW is strongly recommended because NPT may have a reduced pressure rating at high temperature. Both SW and NPT are fully compatible with the PSB design. For critical subsea or wellhead service, SW is preferred.

Q6: What is the difference between Piston and Swing type PSB valves?

A: Piston type uses a piston that moves along the flow axis, providing fast closing and tight sealing — the most common type for Class 900/1500/2500 PSB valves with SW/NPT ends. Swing type uses a hinged disc that swings on a hinge pin, providing lower pressure drop — suitable for NPS 1.5 to 2 sizes in Class 900/1500. For Class 2500, only Piston type is recommended due to the extreme pressure rating. For small-bore (NPS 1/2 to NPS 1), Piston type is generally preferred; for NPS 1.5 to 2 with lower pressure drop requirements, Swing type can be considered.