Threaded Forged Steel Check Valve

Description
Threaded forged steel check valve, also called non return valve, reflux valve, one-way valve or counterbalance valve, is mainly made up of valve body, disc, bonnet and gasket. It is used to prevent back flow and leakage of medium as well as inversion of pump and driving motor. By relying on media flow to open and close disc automatically. It can also be installed on auxiliary system to balance main system pressure. Both swing type and lift type check valves are available in Kayson Valve Company. Threaded forged steel check valves are widely applied in tap water, sewage, construction, petroleum, chemical, food, medicine, textile, electric power, shipbuilding, metallurgy, and other pipeline systems.

Advantages and Features
1. Sealing performance of the forged steel valve is good.
2. It needs small twisting force to close the threaded forged steel check valve.
3. Friction between sealing surfaces is small.
4. Precision casting and CNC processing technology is adopted for making valve body.
5. Disc restrainer is designed to prevent that the open position of disc is too high to be shut down.
6. High strength solid pin is installed precisely, which assures excellent performance and long serving life.
7. Rocker is with high strength and flexibility for disc closing.
8. Disc of threaded forged steel check valve is with high strength and stiffness.
9. The disc sealing surface can be customized. Customer can choose sealing materials like deposited metal material or inset non-metallic material according to requirement.
10. Two times shot blasting processing of valve surface make this forged steel valve look fine and smooth.

Pressure: CLASS900-1500 PN16.0~26.0
1. Bolted Bonnet/Welded Bonnet
2. Full Port
3. Swing Type or Lift Type
4. Treaded Ends or SW Ends

Technical Specification of Forged Steel Valve

Technical Specification	ASME/API/BS	GB/JB
Design Standard	BS5352	GB/T7746
Pressure-Temperature Rating	ASME B16.34	GB/T12224
Face-Face	Factory Standard	GB/T7746
Socket-welded Ends	ASME B16.11	GB/T1751
Threaded Ends	ASME B1.20.1	GB/T306
Inspection & Test	API598	JB/T9092

Material List for Main Parts of Threaded Forged Steel Check Valve

No.	Part name	ASTM
		Carbon Steel		Tailess Steel	Alloy Steel
1	Body	A105	LF2/LF3	A182 F304	A182 F11/F22
2	Seat	A182F6a	A182F6a	A182 F304	A182 F11/F22
3	Disc/Ball	A182F6a	A182F6a	A182 F304	A182F6a
4	Pin	A276-410	A276-410	A276-410	A276-410
5	Spring	Si.Mn Alloy Steel		Stainless Steel	Cr.V Alloy Steel
6	Gasket	Graphite+304
7	Bonnet	A105	LF2/LF3	A182 F304	A182 F11/F22
8	Bolt	A193 B7	A320L7	A193 B8	A193 B16

Main Dimensions & Weight

Pressure		Size		Main Dimension of Forged Steel Valve						Weight (kg)
		mm		in		L		L	H
		Reduce Bore	Full Bore	Reduce Bore	Full Bore	Reduce Bore	Full Bore
CLASS900 PN16.0	Swing Type	15	10	1/2	3/8	10	10	79	61	1.2
		20	15	3/4	1/2	13	13	92	61	1.4
		25	20	1	3/4	18	18	111	78	2.3
		32	25	1-1/4	1	24	24	120	84	3.9
		40	32	1-1/2	1-1/4	29	29	152	103	5.6
		50	40	2	1-1/2	36.5	36.5	172	118	8.9
CLASS1500PN26.0	Lift Type	15	10	1/2	3/8	10	10	79	61	1.0
		20	15	3/4	1/2	13	13	92	61	1.1
		25	20	1	3/4	18	18	111	78	1.9
		32	25	1-1/4	1	24	24	120	84	3.4
		40	32	1-1/2	1-1/4	29	29	120	101	4.5
		50	40	2	1-1/2	36.5	36.5	140	120	7.3

Working Principle
Threaded forged steel check valve allows medium to flow through it in only one direction, and it prevents reverse direction flow. Disc of check valve will open under the pressure of forward flow fluid. When fluid flows in reverse direction, the disc will be closed by fluid pressure and dead weight so as to cut off the flow.

Suggestions
1. When installing threaded forged steel check valve, please ensure that
1) The media flow direction should be consistent with the arrow direction marked on valve body.
2) Vertical disc lift check valves should be installed on vertical pipes.
3) Horizontal disc lift check valve should be mounted on horizontal pipes.
2. The following conditions of threaded forged steel check valve should be inspected regularly after installation:
1) Wear pattern of sealing surface
2) Wear pattern of rotary rocker
3) Dirt accumulation between the inner chamber of the valve body and sealing surface
3. When operating threaded forged steel check valves, do not make the valve bear weight in pipeline. Large check valve should have independent support to ensure that the valve will not be affected by pressure from pipe system.

Malfunction, Reason and Solution

Malfunction	Disc Breakage	Medium Backflow
Reason	The disc beat the valve seat frequently. Some disc valves which are made of brittle materials (such as cast iron, brass, etc.) will be easily broken.	1. Sealing surface is damaged. 2. Impurities are sandwiched between sealing surfaces.
Solution	Applying ductile materials to manufacturer valve disc	Repairing the sealing surface or cleaning impurities