Forged Check Valve 800LBS (NPT & SW Ends )

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

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Forged Check Valve 800LBS - SW, NPT Ends - API 602, BS 5352

Tengs Valve supplies high-quality Forged Check Valves for ANSI Class 800LBS / CL800, manufactured to BS 5352 standards. Available with Socket Weld (SW) and Threaded (NPT) ends, in Bolted Bonnet (BB) or Welded Bonnet (WB) designs. Sizes from NPS 1/2″ to NPS 2″ with Full Bore or Reduced Bore options. Valve types include Ball, Piston, Swing, and Y Pattern. Body materials include forged carbon steel (A105N, LF2), alloy steel (F5, F11, F22), stainless steel (F304, F316), and duplex steel (F51, F53). Ideal for oil & gas, petrochemical, power generation, and instrumentation applications requiring reliable backflow protection in small-bore high-pressure service.

Specifications For Forged Check Valve 800LBS (SW, NPT Ends)

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

• Constructions: Bolted Bonnet (B.B.), Welded Bonnet (W.B.)

• Bore Type: Full Bore / Reduced Bore

• Valve Type: Ball, Piston, Swing, Y Pattern

• Size Range: 1/2″, 3/4″, 1″, 1-1/4″, 1-1/2″, 2″ (NPS 1/2 to NPS 2)

• Pressure Rating: ANSI 800LBS / Class 800 / CL800

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

• Body Materials: A105N, LF2, F5, F11, F22, F304, F316, F51, F53 or Equivalent

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

• Sour Service: NACE MR 0175 on Request

• Test and Inspection: API 598

✓ Class 800 is a forged valve-specific rating between Class 600 and Class 900, ideal for compact high-pressure installations

Bolted Bonnet (BB) vs Welded Bonnet (WB) Forged Check Valve

Parameter	Bolted Bonnet (BB)	Welded Bonnet (WB)
Bonnet Connection	Bolts + gasket	Seal welded to body
Leak Tightness	Good (gasket-dependent)	Excellent (permanent weld)
Maintenance	Easy trim replacement on site	Not repairable; valve must be replaced
Weight & Size	Larger and heavier	More compact and lighter
Typical Application	General service, frequent maintenance	Permanent installation, high-pressure critical service

Reference: BS 5352, API 602. BB is preferred for frequent maintenance; WB is preferred for permanent high-pressure installations where leak tightness is critical.

Socket Weld (SW) vs Threaded (NPT) Ends

Parameter	Socket Weld (SW)	Threaded (NPT)
Connection Type	Welded (socket)	Threaded (screwed)
Standard	ANSI B16.11	ANSI B1.20.1
Leak Tightness	Excellent (welded)	Good (sealant required)
Installation	Requires welding on site	Quick installation without welding
Typical Application	Permanent high-pressure installation	Instrument lines, sampling, temporary connections

Reference: ANSI B16.11, ANSI B1.20.1. SW is preferred for permanent installations; NPT is preferred where quick assembly and disassembly are needed.

Forged Check Valve 800LBS Material List

Part Name	Carbon Steel				Alloy Steel			Stainless Steel
	A105N	A105N	A105N	LF2	F5	F11	F22	F304	F316	F51	F53
	Trim 1#	Trim 8#	Trim 5#	Trim 13Cr	Trim 13Cr	Trim 13Cr	Trim 13Cr	—	—	—	—
Body	A105N	A105N	A105N	LF2	F5	F11	F22	F304	F316	F51	F53
Bonnet	A105N	A105N	A105N	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
Bolts / Nuts	B7 / 2H	B7 / 2H	B7 / 2H	L7 / 4	B16 / 4	B16 / 4	B16 / 4	B8 / 8	B8M / 8M	B8M / 8M	B8M / 8M
Gasket	Graphite	Graphite	Graphite	Graphite	Graphite	Graphite	Graphite	Graphite	Graphite	Graphite	Graphite

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 800LBS 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.

Forged Check Valve 800LBS Applications

• Oil and Gas Industry: Instrument root valves, manifold and flowline backflow protection, sampling systems.

• Power Generation: Steam trap isolation, sensing line isolation, auxiliary high-pressure systems.

• Petrochemical: Hydrocarbon processing, catalytic cracking, reagent feed lines.

• Chemical Processing: Corrosive fluid backflow prevention, dosing systems.

• Water Treatment: High-pressure pump discharge, desalination, boiler feed water.

• Instrumentation: Small-bore high-pressure instrument lines requiring compact installation.

FAQ - Forged Check Valve 800LBS (SW, NPT Ends)

Q1: Why does Class 800 exist only for forged valves?

A: Class 800 is a pressure rating specific to forged steel valves under API 602 and BS 5352, positioned between Class 600 (102 bar) and Class 900 (153 bar) with a design pressure of approximately 138 bar (2,000 psi). It is not part of the standard ASME B16.34 Class 150–2500 sequence for cast valves. Forged valves have thinner walls and smaller sizes, so Class 800 fills the gap between Class 600 and Class 900 for small-bore high-pressure service. Class 800 is widely used for instrument lines, sampling systems, and compact high-pressure installations.

Q2: What is the difference between SW and NPT ends?

A: SW (Socket Weld) ends are welded to the pipe, providing excellent leak tightness and are preferred for permanent high-pressure installations. NPT (Threaded) ends are screwed onto the pipe, allowing quick assembly and disassembly without welding — preferred for instrument lines, sampling systems, and temporary connections. SW follows ANSI B16.11; NPT follows ANSI B1.20.1. NPT requires a sealant (PTFE tape or pipe dope) to ensure leak tightness.

Q3: What is the difference between BB and WB bonnet designs?

A: Bolted Bonnet (BB) uses bolts and a gasket to secure the bonnet, allowing easy trim replacement on site. Welded Bonnet (WB) has the bonnet seal-welded to the body, providing better leak tightness and a more compact design, but the valve cannot be repaired — it must be replaced if the trim fails. BB is preferred for general service with frequent maintenance; WB is preferred for permanent high-pressure installations where leak tightness is critical.

Q4: How do I choose between Ball, Piston, Swing, and Y Pattern types?

A: Ball type uses a ball that moves along the seat — suitable for viscous fluids and varying flow rates. Piston (Lifting) type uses a piston that moves along the flow axis — suitable for high-pressure small-bore service with fast closing. Swing type uses a hinged disc that swings on a hinge pin — suitable for larger sizes and low pressure drop. Y Pattern has an angled body with a lift disc — suitable for reduced pressure drop and high flow capacity. For NPS 1/2 to 2 high-pressure service, Piston or Ball type is most common; Swing is preferred for slightly larger sizes.

Q5: Why are SW and NPT ends preferred for small-bore forged valves?

A: Small-bore forged valves (NPS 1/2 to 2) are typically used in instrument lines, sampling systems, and compact high-pressure installations where space is limited. Flanged ends would add weight and require more space. SW and NPT ends provide a compact, low-profile connection that is ideal for these applications. SW is preferred for permanent installations; NPT is preferred where quick assembly and disassembly are needed.

Q6: What is the difference between Full Bore and Reduced Bore?

A: Full Bore (Full Port) forged check valves have an internal bore equal to the pipe inner diameter, providing minimal pressure drop and allowing pigging operations. Reduced Bore (Reduced Port) has a smaller internal bore, resulting in higher flow velocity and better sealing performance, but with additional pressure drop. For small-bore instrument and sampling lines, Reduced Bore is often acceptable and more economical. For pipeline and process service, Full Bore is preferred.