365bet足球投注网

Contact Us

Fakai Valve Factory Site: Yongxing Industrial Zone, Longwan District, Wenzhou City Tel: 0577-88767789
Fax: 0577-85983279
Mobile: 15958706338
Contact: Mr. Wang Email: 1552028357@qq.com
Website: http://timbuist.com

Introduction to the structure and design standards of check valves

Release Date: January 16, 2016

Check valve is also called check valve, check valve, check valve or check valve. Its function is to ensure the directional flow of the medium in the pipeline without reverse flow. The foot valve of the pump suction pipe also belongs to the check valve category.

Check valve

Check valve is an automatic valve. The pressure is 1.6 ~ 25MPa / Class150-2500 / 2.0-42.0MPa, the working temperature is -29 ~ + 550 ℃, the materials are usually: cast steel WCB, cast iron HT200, HT250, QT350, QT450, alloy steel WC6 , WC9, CN7M stainless steel has CF8 (M), CF3 (M). Forged steel has A105, F304 (L), F316L, etc. It is applicable to pipelines under various working conditions such as petroleum, chemical, pharmaceutical, fertilizer, power industry The medium is water, oil, steam, acid medium, etc. It is a valve that controls the unidirectional flow of the medium in the pipeline to prevent the medium in the pipeline from flowing backward. Its structural form and design standards are:

Serial number

name

Structural features

Applicable design standards

1

Vertical lift check valve

1. Flow channel: horizontal through, angle, DC (Y type)

2. Connection between valve body and bonnet: flange, external thread

3.Flange end

BS5352-1981: flange, butt welding, internal thread, socket welding

JB / T7749-1995: socket welding, internal thread

JPI-7S-36-1999: socket welding, internal thread

4. Valve disc: ball (BS5352-1981), flat seal plug, cone seal plug

BS5352-1987

JB / T7746-1995

JPI-7S-36-1999

MSS-SP-42-1995

BS1868-1991

BS5160-1989

GB / T12235-1989

2

Straight-through lifting check valve

1. Flow channel: vertical straight through

2. Connection between valve body and bonnet: flange, external thread

3.Flange end

BS5352-1981: flange, butt welding, internal thread, socket welding

JB / T7749-1995: socket welding, internal thread

JPI-7S-36-1999: socket welding, internal thread

4. Valve disc: ball (BS5352-1981), flat seal plug, cone seal plug

BS5352-1981

BS1868-1991

3

Internal pressure self-tightening seal

1. Flow channel: horizontal straight through

2. Connection between valve body and bonnet: self-tight seal with internal pressure

3. Connection end: flange, butt welding, socket welding

4. Valve disc: cone seal or flat seal plunger

ASMEB16.34-1996

(Butt welding, flange, connection)

BS5352-1981

(Reference socket)

4

Lifting check valve with compression spring

1, runner: angle

2. Connection between valve body and valve cover: flange

3. Connection end: flange, thread, socket welding

4. Valve disc: ball, flat seal plunger, cone seal plunger

BS1868-1991

BS5352-1981

JB / T7746-1995

JPI-7S-36-1999

ASMEB16.34-1996

BS5160-1989

5

Single flap bottom valve

1. Flow channel: vertical straight through

2. Connection with pipe: flange

3. Valve disc: plane sealing plug shape

BS5352-1987

JB / T7746-1995

JPI-7S-36-1999

MSS-SP-42-1995

BS1868-1991

BS5160-1989

GB / T12235-1989

6

Double flap swing bottom valve

The disc is a double-lobe swing-open type, and the rest is the same as No. 5 and has the same principle as the swing-type check valve (the principle of the large multi-lobe swing-type check valve is the same)

reference

API594-1991

7

With slow-closing swing check valve

1. Flow channel: horizontal straight through

2. Connection between valve body and valve cover:

Diameter ≤150, flat cover flange

Diameter ≥200, butterfly flange

3. Connection end: flange, butt welding

4, rocker fixed: the rocker penetrates out of the body, the rocker is fixed on the valve cover (upper support), the rocker is fixed on the valve body (convex table in the valve body) but does not penetrate the body

JISB2074-1991

GB / T12236-1989

ASMEB16.34-1996

MSS-SP-42-1995

API-6D-2002

BS1868-1991

JPI-7S-46-1999

API594-1991

8

Internal pressure self-tightening check valve

1. Flow channel: horizontal straight through

2, the valve body and valve cover connection: internal pressure self-tight seal

3. Connection end: flange, butt welding

4. Rocker fixation: The rocker sticks out of the body, and the rocker is fixed on the boss in the valve body, but does not stick out

ASMEB16.34-1996

9

Swing check valve with buffer mechanism

Buffer mechanism: 1, rotary type 2, piston type

10

Butterfly check valve

The internal structure and operating principle are the same as those of the butterfly valve, and the rotary shaft supporting the disc is as safe as the swing check valve

11

Swing check valve

1, runner: straight-through

2. Valve body and bonnet connection: bolt connection

3.The valve body, bonnet and disc are made of cast steel

4.Surface welding of cemented carbide on valve seat and valve disc sealing surface

GB / T12236-1989

API6D-2002

12

Wafer swing open double flap check valve

1, runner: straight-through

2. Valve body: cast steel

3. Valve disc: double plate, with spring return and open at a certain angle to the level to close

4.Single and double stem

JB / T8937-1999

API6D-2002

13

Single ball non-wearing ball check valve

1, runner: straight-through

2.The valve body and valve cover are made of cast steel

3. Valve body and bonnet connection: bolt connection

4. Ball guides in the valve body

5.The sphere is made of hollow steel coated rubber for easy sealing

6.Suitable for nominal diameter DN≤150mm

14

Multi-ball non-wearing spherical check valve

1, runner: straight-through

2. Valve body: bonnet: welded from cast steel or steel plate

3. Valve body and bonnet connection: bolt connection

4. Ball guides in the valve body

5.The sphere is made of hollow steel coated rubber for easy sealing

6.Suitable for nominal diameter DN200 ~ 600mm

15

Flange with damping butterfly check valve

1, runner: straight-through

2.The valve body and butterfly plate are cast steel parts

3.The butterfly plate rotation shaft is located in the valve body with damping pins on the butterfly plate

4.The valve body is provided with a damping cylinder with a spring

5.The valve body has a limit device after opening

6.The valve is sealed like an eccentric butterfly valve

API6D-2002

16

Check valve

1. Flow channel: horizontal straight

2. Connection between valve body and valve cover: flange

3. Connection end: flange, butt welding

4. Plane valve disc (suitable for nominal diameter ≤50mm)

BS1873-1990

17

Stop check valve for boiler feed water

1, runner: angle

2. Connection between valve body and valve cover: flange

3. Connection end: flange

4. Check valve disc: Spherical or conical valve disc with guide device

Refer to BS1873-1990

18

Y-type lifting check valve with diversion tube

1. Flow channel: DC type

2. Connection between valve body and valve cover: pressure self-sealing

3. Connection end: flange, butt welding

4. Valve disc: Spherical or conical sealing plug valve disc. There is a return conduit between the valve disc and the outlet end.

ASMEB16.24-1991

19

Air check valve

Role: Prevent the medium at the outlet end of the valve from flowing back under atmospheric pressure, and discharge the pressure medium remaining at the inlet end of the valve.

20

Full pressure valve

Role: Installed on the ventilation duct, automatically adjust the internal and external pressure difference (nominal diameter 150 ~ 400mm, pressure 0.67 ~ 2.4MPa)

Wenzhou Xinrongda Valve Fittings Co., Ltd. currently produces products such as regulating valves and accessories, general-purpose valves, temperature reducing and reducing devices, automatic recirculation control valves, solenoid valves, API6A valves and so on. Control valves and accessories include: pneumatic control valves, electric control valves, self-operated control valves, manual control valves, pneumatic diaphragm actuators, electric actuators, electrical valve positioners, electric valve adjustment modules, etc.