Butt Welded Forged Steel Check Valve

Introduction
Check valve, also known as non return valve, reflux valve, one-way valve or counterbalance valve, opens and closes automatically depending on media flowing pressure. Butt weld forged steel check valve is mainly composed of include valve body, disc, bonnet and gasket. We have swing check valve and lift check valve.

Application
This type of forged steel valve is used to prevent reverse flow and leakage of medium, such as fluid, gas, etc. It is also applied to stop reversal of pump and driving motor. Butt weld forged steel check valve can be widely applied as fluid regulating and intercepting equipment in tap water, sewage, construction, petroleum, chemical, food, medicine, textile, electric power, shipbuilding, metallurgy, and other pipeline systems.

Advantages
1. Sealing material can be selected according to medium so as to enhance reflux valve’s sealing property and wear resistance.
2. It needs small twisting force to close butt weld forged steel check valve.
3. Friction between sealing surfaces is small.
4. The disc sealing surface can be customized. Customer can choose sealing materials like deposited metal material or inset non-metallic material according to requirement.
5. All our check valves are guaranteed for 18 months. Lifelong technology consultancy service is available for our products.

Features of Butt Weld Forged Steel Check Valve
1. Precision casting and CNC processing technology is adopted for making valve body.
2. Disc restrainer is designed to prevent that the open position of disc is too high to be shut down.
3. High strength solid pin is installed precisely, which assures excellent performance and long serving life.
4. Rocker is with high strength and flexibility for disc closing.
5. Disc of butt weld forged steel check valve is with high strength and stiffness.
6. Sealing performance of the forged steel valve is good.
7. Two times shot blasting processing of valve surface make this forged steel valve look fine and smooth.
8. Full port is one of this reflux valve’s main features.

Classification of Butt Weld Forged Steel Check Valve
1. According to Pressure: CLASS150/300/600
2. According to Bonnet: Bolted Bonnet or Welded Bonnet
3. Swing Type or Lift Type
4. According to End: Flange End or Butt Weld End

Pressure: CLASS150~600
1. Bolted Bonnet/Welded Bonnet
2. Full Port
3. Swing or Lift Type
4. Flange Ends or Butt-Welding Ends

Technical Specification

Design Standard	ASME B16.34/BS5352
Pressure-Temperature Rating	ASME B16.34
Face-Face	ASME B16.10
Flange Ends	ASME B16.5
Buttwelding Ends	ASME B16.25
Inspection & Test	API598

Material List for Main Parts of Butt Weld 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 of Butt Weld Forged Steel Check Valve

Pressure	Size		Main Dimension of Valve Reflux Valve
	mm	in.	d	LRF	LBW	H		Weight(kg)
						Lift type	Swing type
CLASS150	15	1/2	13	105	105	61	61	3.4
	20	3/4	18	117	117	78	78	4.4
	25	1	24	127	127	84	84	8.2
	32	1-1/4	29	140	140	103	101	8.9
	40	1-1/2	36.5	165	165	118	120	12.0
	50	2	46.5	203	203	130	133	14.3
CLASS300	15	1/2	13	152	152	61	61	3.7
	20	3/4	18	178	178	78	78	4.8
	25	1	24	203	203	84	84	8.8
	32	1-1/4	29	216	216	103	101	9.6
	40	1-1/2	36.5	229	229	118	120	13.7
	50	2	46.5	267	267	130	133	17.8
CLASS600	15	1/2	13	165	165	61	61	4.0
	20	3/4	18	190	190	78	78	5.8
	25	1	24	216	216	84	84	9.5
	32	1-1/4	29	229	229	103	101	10.4
	40	1-1/2	36.5	241	241	118	120	15.6
	50	2	46.5	292	292	130	133	24.5

Note: H means the height when reflux valve is fully opened.

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

Working Principle
Butt weld forged steel check valve allows medium to flow through it in only one direction, and it prevents reverse direction flow. Disc of reflux 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.

Payment, Package and Transportation
1. Butt weld forged steel check valves can be paid by T/T, D/P, D/A, L/C, and so on.
2. Standard exporting wooden cases are employed for packaging.
3. Products are transported by air, sea or railway.