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Wafer type dual plate check valve: metal seated vs resilient seated

Wafer dual plate check valve is used for pure pipelines and industrial, environmental protection, water treatment, high-rise building water supply and drainage pipelines, to prevent the reverse flow of the medium. The check valve adopts a clamp type, the butterfly plate is two semicircles, and it adopts a spring for forced reset. The sealing surface can be built-up welding wear-resistant material or rubber lining, with a wide range of use and reliable sealing.

The check valve opening and closing parts are opened or closed automatically by the flow and force of the medium to prevent the medium from flowing back. The valve is called the check valve. Check valves belong to the category of automatic valves, which are mainly used in pipelines where the medium flows in one direction, and only allow the medium to flow in one direction to prevent accidents.

According to the structure of the check valve, it can be divided into three types: lift check valve, swing check valve and butterfly check valve. Lift check valves can be divided into two types: vertical and horizontal. Swing check valves are divided into three types: single valve, double valve and multi valve. The butterfly check valve is a straight-through type. The above-mentioned check valves can be divided into three types in connection form: threaded connection, flange connection and welding. A check valve is a valve that can automatically prevent fluid from flowing back. The disc of the check valve is opened under the action of fluid pressure, and the fluid flows from the inlet side to the outlet side. When the pressure on the inlet side is lower than that on the outlet side, the valve flap is

H46-double flanged dual plate check valve-metal seated

H46-double flanged dual plate check valve-metal seated

automatically closed under the action of the fluid pressure difference, its own

lug type dual plate check valve metal seated (3)

lug type dual plate check valve metal seated (3)

gravity and other factors to prevent the fluid from flowing back.

klug type dual plate check valve metal seated (1)The dual plate check valve is divided into flange dual plate check valve, lug dual plate check valve and wafer dual

plate check valve.

Classification of wafer dual plate check valves: hard-seal wafer dual plate check valve and soft-seal wafer dual plate check valve; of which soft-seal wafer check valve is divided into full-lined soft-seal wafer check valve and Semi-lined/normal soft-seal wafer dual plate check valve.

Features of Wafer dual plate Check Valve:

  1. Simple structure and light weight, especially suitable for low-pressure large-diameter pipelines;
  2. The paired clamp connection mode, the production process is simple, and the disassembly and assembly are convenient;
  3. The check valve adopts the clamp type, the butterfly plate is two semicircles, and the spring is forced to reset. The sealing surface can be built-up welding wear-resistant material or rubber lining, with a wide range of use and reliable sealing.

Model: H76X/H76H/H76W
Name: Wafer dual plate check valve
Please refer to the main technical parameters and spare parts materials:
https://www.tanghaivalve.com/wafer-type-double-disc-swing-check-valve-introduction/
Product name: Wafer double plate check valve (soft seal)
National Standard Number: H76X

dual plates check valve photos-normal sealing (1)

dual plates check valve photos-normal sealing (1)

Size range: DN40-DN1200
Pressure rating: PN10/16/25/40/64/100
Valve features: double valve plate design, short running track of the valve plate, spring load makes the valve plate close more quickly, effectively preventing water hammer
When the valve plate is opened, it is close to 90 degrees, and the pressure loss is small
Zero leakage
Size range: 2″ to 48″
Pressure range: 10bar-50 bar
Suitable flange: National standard or EN1092 PN10/PN16/PN25/PN40 or ANSI 125/150/300
Structure length: EN558 series 16, API594

Body material: gray cast iron, ductile iron, carbon steel, stainless steel, aluminum bronze
Valve plate material: ductile iron nickel-plated, stainless steel 201, stainless steel 304,

dual plates check valve photos- full rubber

dual plates check valve photos- full rubber

stainless steel 316, aluminum bronze
Valve seat material: nitrile NBR, EPDM, oil and acid and alkali resistant fluorine rubber VITON-A, steam resistant fluorine rubber VITON-B, hard seal
Uses: Suitable for installation at the outlet of high-lift pumps, or as a bottom valve in front of the pump, suitable for water, sea water, steam, oil, chemicals, chlorine, oxygen, and steam. Can be installed horizontally or vertically.
Application scope:
It is suitable for industrial, environmental protection, sewage treatment, high-rise building water supply and drainage pipelines, etc. It can also be used for environmental systems with corrosive media such as power plants and steel plants gypsum slurry.

 

Product name: Wafer double plate check valve (metal seated)
National standard number: H76H(W)-16C(16P, 16R, 16RL)
Size range: DN40-DN1200

H76-wafer type dual plate check valve metal seated

H76-wafer type dual plate check valve metal seated

Pressure rating: PN10/16/25/40/64/100
Temperature range: -20℃ -350℃
Body material: WCB, A105, CF8, CF3, CF8M.CF3M and other materials and special steel
Valve plate material: WCB, A105.2CR13, 304.304L.316.316L and other materials and special steel
Valve shaft material: A105.2CR13, 304.304L.316.316L and other materials and special steel
Valve seat material: 2CR13, 304.304L.316.316L, STL and other materials and special steel
Application range: water, steam, oil, nitric acid, acetic acid, strong oxidizing medium and urea and other media
More video for wafer dual plate check valve, please see below:
https://www.youtube.com/watch?v=pGrkznOd-JA
https://youtu.be/etwT8RX-S3Q
https://www.youtube.com/watch?v=XqRRI7o-LFI

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news/knowledge:

Working principle diagram of swing check valve

Working principle diagram of swing check valve
Swing check valve, also known as check (flow) valve, is an automatic valve used on one-way flow pipelines to prevent the medium from flowing back. It depends on the pressure of the pipeline medium to open or close the valve. It can be divided into single valve type , Double valve type and multi valve type, are one of the more commonly used valves. Swing check valves are generally suitable for pipelines with relatively clean fluid media. They are not suitable for

swing-check-valve-working-principle-diagram

swing-check-valve-working-principle-diagram

working conditions with high viscosity or solid particles. Otherwise, the check valve will be insensitive to opening and cannot achieve a complete seal. The answer is not reliable enough. The swing check valve only allows the medium to flow in one direction, which can effectively prevent the medium from flowing back to prevent accidents.

The working principle of the swing check valve:
The disc of the swing check valve and the rocker are connected together, and can rotate a certain angle around the pin shaft. When the pipeline fluid flows in the specified direction (from left to right), the inlet pressure of the disc is higher than the outlet pressure. At this time, the disc is pushed away from the valve seat and rotates around the pin to a certain position, and the valve is in the open state. When the pressure difference between the two sides of the valve flap decreases to a certain level, the valve flap falls and returns to the closed state. When the fluid flows from right to left, that is, reverse flow, the pressure on the right side of the valve disc is higher than the pressure on the left side, and the force generated by the pressure difference on both sides presses the valve disc on the valve seat, and the fluid cannot pass through, the medium Can not flow back; and the greater the fluid pressure, the tighter the sealing surface is, and the better the sealing effect. To

The installation position of the swing check valve is not restricted. It can be installed horizontally in the pipeline, or on a vertical or inclined pipeline, but if it is installed on a vertical pipeline, the flow direction of the medium should be from bottom to top.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news/knowledge:
Basic knowledge of valve;
What is double plate swing check valve;
Butterfly valve use principle and installation instructions;
Wafer type double disc swing check valve introduction

Working principle diagram of lift check valve

Lifting check valve structure:

Lifting check valve is a kind of valve that prevents pipeline media from flowing back, mainly composed of valve body, valve seat, valve flap, valve cover and other related parts. The lift check valve is equipped with a spring to ensure that the disc is always in a dynamic equilibrium state under the action of the spring. Regardless of the medium pressure at the inlet of the valve, the valve can maintain a balanced operation.

lift check valve Working principle diagram

lift check valve Working principle diagram

The working principle of the lift check valve:

The lift check valve has a guide rod on the disc, which can move up and down freely in the guide hole of the valve cover. When the pipeline medium flows in in the specified direction (from left to right), and the pressure below the valve flap exceeds the pressure above it, push the valve flap to rise along the center line of the guide hole of the valve cover, and the valve will automatically open to allow the medium to flow; if the fluid flows from the right to the right Left flow, that is, when it flows backward, the pressure above the valve flap is greater than the pressure below it. The pressure difference between the upper and lower pressures and the weight of the valve flap press the valve flap on the valve seat, so that the medium cannot pass through, that is, the fluid cannot flow back; and pipeline fluid The greater the pressure, the tighter the sealing surface is, and the better the sealing effect.

The seat sealing surface of the lift check valve can be welded, or it can be made into a seat sealing ring and then expanded or threaded on the valve body; when the valve body is made of stainless steel, the sealing surface can also be on the valve body It is directly processed from above. The sealing surface of the disc can be directly processed on the disc, or can be processed after surfacing or welded on the disc with the inner and outer periphery of the sealing ring. The straight-through lift check valve can only be installed on the pipeline in a balanced way, and the center line of the valve flap is vertical to the horizontal plane, while the vertical lift check valve is not subject to this restriction.

Introduction of cast steel lift swing check valve

1. Overview of Cast steel lift check valve:

The lift check valve is selected for the pipelines of various working conditions such as petroleum, chemical industry

lift swing check valve (2)

lift swing check valve (2)

and thermal power plants with a nominal pressure of PN1.6~6.4MPa and a working temperature of -29~550℃. Applicable media are: water, oil, steam, etc.

2. Structural features of Cast steel lift check valve:

1. Exquisite selection of materials, in line with domestic and foreign standards, the highest quality of materials.

2. The sealing pair is advanced and reasonable. The sealing surface of the valve disc and the valve seat is made of iron-based alloy or Stellite cobalt-based cemented carbide. It has good wear resistance, high temperature resistance, corrosion resistance and scratch resistance. ,long lasting.

3. The products are designed and manufactured according to the national standard GB/T12235.

4. Various piping flange standards and flange sealing types can be used to meet various engineering needs and user requirements.

5. The valve body has a complete range of materials, and the gasket can be reasonably selected according to actual working conditions or user requirements, and can be suitable for various pressure, temperature and medium working conditions.

According to user requirements, check valves with different structures and connections can be designed and manufactured for use with various equipment.

H41H lift check valve: Do not allow the check valve to bear weight in the pipeline. Large-scale check valves should be independently supported to prevent them from being affected by the pressure produced by the pipeline system. When installing, pay attention to the direction of medium flow should be consistent with the arrow direction indicated by the valve body. Suitable for water, steam, oil, nitric acid, acetic acid, oxidizing medium, urea and other media.

H41H, H41Y type PN16~PN100 lifting steel check valve is one of the important links in the production process regulation system. It is a valve that controls the one-way flow of the medium in the pipeline to prevent the medium from flowing back. It is widely used in purification equipment, petroleum, chemical industry, metallurgy, electric power, textile and other production processes.

Product features of lift check valve:

1. H41H and H41Y lift-type steel check valves have the advantages of simple structure, reliable action and convenient maintenance.

2. When the medium flows into the valve body from the direction indicated by the arrow of the valve body, the pressure of the medium acts on the valve flap to produce an upward thrust. When the medium thrust is greater than the weight of the valve flap, the valve opens. When the force of the medium pressure acting on the disc after the valve plus the weight of the disc itself is greater than the force of the pressure acting on the disc before the valve, the valve is closed to prevent the medium from flowing back.

Lift check valve refers to the valve that automatically opens and closes the valve flap depending on the flow of the medium itself to prevent the medium from flowing back, also known as check valve, one-way valve, reverse flow valve, and back pressure valve. Check valve is a kind of automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and discharge the container medium. Check valves can also be used to supply pipelines for auxiliary systems whose pressure may rise above the system pressure. Check valves can be divided into swing check valves (rotating according to the center of gravity) and lift check valves (moving along the axis).

Check valves are also called check valves, check valves, reverse flow valves, and back pressure valves.

The function of the check valve is to only allow the medium to flow in one direction and prevent the reverse flow. Usually this kind of valve works automatically. Under the action of the fluid pressure flowing in one direction, the valve flap opens; when the fluid flows in the opposite direction, the fluid pressure and the self-coincidence of the valve flap act on the valve seat, thereby cutting off the flow. Among them, the internal thread check valve and the butterfly check valve belong to this type of valve.

It includes swing check valve and lift check valve. The swing check valve has a hinge mechanism and a valve flap like a door that rests freely on the inclined valve seat surface. In order to ensure that the valve clack can reach the proper position of the valve seat surface every time, the valve clack is designed in a hinge mechanism so that the valve clack has enough space for rotation and makes the valve clack really contact the valve seat. The valve disc can be made of metal, or inlaid with leather, rubber, or synthetic covering, depending on the performance requirements. When the swing check valve is fully opened, the fluid pressure is almost unimpeded, so the pressure drop through the valve is relatively small. The valve disc of the lift check valve is seated on the sealing surface of the valve seat on the valve body. Except that the disc can be lifted and lowered freely, the rest of this valve is like a shut-off valve. The fluid pressure lifts the disc from the sealing surface of the valve seat, and the backflow of the medium causes the disc to fall back onto the seat and cut off the flow. According to the conditions of use, the valve disc can be an all-metal structure, or it can be in the form of a rubber pad or a rubber ring inlaid on the disc holder. Like a shut-off valve, the passage of fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow rate of the swing check valve is restricted Rarely.

Swash plate type non-impact check valve

“Swash plate check valve” generally refers to tilting disc swing check valve.

Chinese name: PXH44H-150LB swash plate type non-impact check valve

8 tilting-disc-swing-check-valve-3

8 tilting-disc-swing-check-valve-3

Structure length: ASME B16.10
Product design press: ASME B16.34
Inspection and testing: API 598

PXH44H-150LB swash plate type non-impact check valve details:

1. Product overview:

It is a new type of check valve developed by combining our company’s many years of valve production technology with foreign advanced product design and development. Its main advantage is to overcome the impact and water hammer caused by the swing check valve and the lift type upper return valve under working conditions. Phenomenon, to achieve no impact operation.

2. Design specifications:

Flange size according to: ASME B16.5 GB HG SH

Pressure rating: Class 150, 300, 600 PN 2.0, 5.0, 10.0 MPa

3. Structural features:

The double eccentric valve flap gradually contacts the sealing surface when it is closed, so that it can work without impact and noise.

Micro-elastic metal seat with good sealing performance.

Butterfly valve disc design, fast, sensitive and long service life.

The swash plate structure makes the fluid channel streamlined, with low flow resistance and energy saving effect.

4. Materials for main parts:

code valve body valve flap valve sealing/seat
P CF8 CF8+STL 0Cr19Ni9 PTFE
R CF8M CF8M+STL 0Cr17Ni12Mo2
K CF3 CF3+STL 00Cr19Ni11
J CF3M CF3M+STL 00Cr17Ni14Mo2
E CN7M CN7M+STL 20 alloy
C WCB WCB+13Cr 0Cr19Ni9
D LCB CF8+STL 0Cr19Ni9

5. Main properties:

Items normal swing check valve swash plate type non-impact check valve
Closing force big small(about 1/5~1/8 of the former)
compact force big None
sealing  performance as per API 598, leakages allowed can realize no leakage
flow resistance big(ξ=1.3~2.5) small(ξ=0.18~0.6)
flow ability small(Cv=76) big(Cv=154~333)
weight big small(about 80% of former)

Related news /knowledge:
Current status and development of Chinese valves;
Classification of check valves;
What is double plate swing check valve;
Wafer type double disc swing check valve introduction;

The difference between one-way valve and check valve

One-way valve means that the fluid can only flow along the water inlet, and the medium at the water outlet

double-wing-check-valve-3

double-wing-check-valve-3

cannot return. Used in hydraulic systems to prevent reverse flow of oil or pneumatic systems to prevent reverse flow of air. Check valve refers to a valve whose opening and closing parts are circular discs and rely on its own weight and medium pressure to generate actions to block the back flow of the medium. It is an automatic valve.

There are two types of check valves: straight-through and right-angle. The straight-through check valve is installed on the pipeline with a threaded connection. Right-angle check valves have three forms: threaded connection, plate connection and flange connection. Hydraulic control check valve is also called lock valve or pressure maintaining valve. It is the same as check valve to prevent reverse flow of oil. However, when the oil flow is required to flow in the reverse direction in the hydraulic circuit, the oil pressure can be controlled to open the one-way valve so that the oil flow can flow in both directions. The hydraulic control check valve adopts a conical valve core, so the sealing performance is good. When the oil circuit is required to be closed, this valve can be used as a one-way locking of the oil circuit to maintain pressure. There are two types of hydraulically controlled check valve to control oil leakage: internal leakage and external leakage. The internal drain type can be used in the oil circuit where the oil flow reverse outlet has no back pressure; otherwise, the external drain type is required to reduce the control oil pressure.

The  check valve can also be used to supply the auxiliary system whose pressure may rise above the system pressure. Check valves can be divided into swing check valves (rotating according to the center of gravity) and lift check valves (moving along the axis). The function of this type of valve is to only allow the medium to flow in one direction and prevent the flow in the opposite direction. Usually this kind of valve works automatically. Under the action of the fluid pressure flowing in one direction, the valve flap opens; when the fluid flows in the opposite direction, the fluid pressure and the self-coincidence of the valve flap act on the valve seat, thereby cutting off the flow.

One-way valve is a directional control valve in which air flow can only flow in one direction but not in the reverse direction. Its working principle is the same as the hydraulic one-way valve. Compressed air enters from port P, overcomes the spring force and friction force to open the one-way valve port, and the compressed air flows from P to A; when there is no compressed air at port P, it will be under the action of spring force and remaining force of port A (cavity) ; The valve port is in the closed state, so that the air flow from A to P is blocked. The one-way valve is used in occasions where the air flow is not allowed to flow in the opposite direction. For example, when the air compressor is inflating the air tank, a one-way valve is set between the air compressor and the air tank to prevent the air tank when the air compressor stops working. The compressed air in the air flow is returned to the air compressor. One-way valves are often combined with throttle valves and sequence valves to form one-way throttle valves and one-way sequence valves.

Check valves have a wide range of uses, and there are many types. The following are the check valves commonly used in water supply and heating:

1. Spring type: the liquid is from bottom to top, and the valve clack controlled by the spring is pushed up by the pressure. After the pressure disappears, the spring force pushes down the valve clack to seal the liquid back flow. Often used for check valves with small diameters.

2. Gravity type: Similar to spring type, it is closed by the gravity of the valve disc to prevent backflow.

3. Swing type: The liquid flows directly through the valve body, and the rotating disc on one side is opened by the pressure. After the pressure is lost, the disc relies on its own weight to return to the position, and the reverse liquid pressure closes the disc.

4. Plastic diaphragm type: Both the shell and the diaphragm are plastic. The general shell is ABS, PE, PP, NYLON, PC. The diaphragm includes silicone resin, fluororesin, etc.

In general, the check valve and the check valve are basically the same thing, but there are some differences. The check valve is a controlled check valve, and the check valve is a non-controlled check valve. That is to say, the one-way valve is used to provide pressure, and its main function is to maintain pipeline pressure. Although the check valve can also provide this function, it is mainly used to control the return of the medium and does not require pressure.

The above is about the difference between check valve and check valve. In fact, a check valve is only one type of valve, and a oneway valve is only a type of check valve. It is only a one-way open-close valve that prevents backflow of fluid in various pipelines or equipment. Check valves have a wide range of uses.

Related news /products:
The principles and difference between one-way valve and check valve;
The difference between globe valve and check valve;
Working principle diagram of three-way valve;
Valve actuator / actuation -(3)-classifications;

What is double plate swing check valve

Main features of Double plate swing check valve:

double wing check valve (5)

double wing check valve (5)

Two valve plates are fixed on the valve body along a pivot axis, and two springs are installed on the butterfly plate above the sealing surface. Driven by the pressure of the medium flow, the spring is compressed to force the butterfly plate to open. When the medium flows back , The spring forces the valve to close. This kind of valve can be assembled on horizontal and vertical pipelines.

Design Features of Double plate check valve:
Design standard: API 594, API 6D, ASME B16.34, GB/T 12236
Good sealing performance
Small size and light weight
Wide application, flexible disc, fast closing
Valve plate closes quickly
Small closing impact

Product Range:
Body material: carbon steel, stainless steel, alloy steel
Caliber: 1/2″~60″(DN15~DN1500)
Pressure range: Class150~2500 (PN10~PN420)
Connection method: RF, RTJ, BW
Working temperature: -196℃~+560℃

TH VALVE is one of the largest double plate check valve manufacturers in China, main products are butterfly valves, check valves: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)

Related news /products:
Wafer type double disc swing check valve introduction;
Working principle diagram of swing check valve;
Installation instructions of double eccentric butterfly valve;

What is a Single-disc swing check valve

Product details of Single-disc swing check valve:
Brand: THV

single disc swing check valve body

single disc swing check valve body

Type: TH-CKV-SDS
Material: Stainless steel, cast iron, etc.
Connection form: Wafer structure Butterfly type
Nominal diameter DN15-DN400 (mm)
Applicable medium: fresh water, sea water, steam, food, medicine —-
Form Butterfly Pressure Environment Normal Pressure Standard British Standard American Standard National Standard Flow Direction Two-way Drive Mode Manual Operating Temperature Normal Temperature Type (Channel Position) Straight-through

Applicable medium:
Fresh water, sea water, air, steam, food, medicine, and various oils, acids, alkalis, salts, etc.

Features of single disc swing check valve:
Long service life, reliable sealing performance and no frequent maintenance. The flow characteristic of the butterfly valve is 3 times that of the globe valve and 75% of the gate valve of the same specification. The butterfly valve can realize the switching and regulating function of the fluid in the pipeline. Compared with the gate valve and the stop valve, it has a better multifunctional type. The various choices of internal parts and elastic materials make butterfly valves widely used in the chemical industry.

The butterfly valve is light in weight and small in size. For example: the weight and volume of a 10″ butterfly valve are respectively 1/9 and 1/6 of a 10″ gate valve. Therefore, the butterfly valve is easy to install and can save the cost of the piping system. Compared with metal-sealed gate valves and globe valves, soft-sealed butterfly valves can achieve complete air tightness. The butterfly valve is easy to operate and can realize the opening and closing function within a 90° rotation range. The price of the butterfly valve of the same specification is about 35-40% of the price of the gate valve, and the installation cost of the butterfly valve is relatively low. The correctly installed butterfly valve has a certain degree of self-cleaning, and it is not easy to fail due to the stolen goods in the pipeline.

Note: The valve connecting flange size in this table conforms to BS4504 PN10, and the transmission connecting flange size conforms to ISO5211. In addition, it also meets the flange connection standards of other countries and the special connection sizes required by customers.

TH valve is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves.., Main products: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)

Related news/products:
Wafer type double disc swing check valve introduction;
Working principle diagram of swing check valve;
Classification of check valves;

What is a single plate check valve

Single-plate check valve is also called single-disc check valve, wafer check valve: it is a valve that can automatically

6 single-plate-swing-check-valve-2

6 single-plate-swing-check-valve-2

prevent fluid backflow. The disc of the check valve is opened under the action of fluid pressure, and the fluid flows from the inlet side to the outlet side. When the pressure on the inlet side is lower than that on the outlet side, the valve flap is automatically closed under the action of the fluid pressure difference, gravity and other factors to prevent the fluid from flowing back. It can be installed horizontally or vertically. For vertical installation, pay attention to the water flow from bottom to top, and pay attention to whether the installation direction is correct.

There are two types of check valves. One is installed at the end of the vertical suction pipe in front of the water pump bai. The purpose is to fill the water pump without pumping water once, because the water pump can only be used when there is no water in the pump and the suction pipe in front of the pump. Idling cannot pump water, so the pump must be filled with water to pump out water. The installation of this pump is a method when it is above the liquid level. It is also called a negative pressure method such as pumping water up from a well. Another way to install the pump is that the liquid level is higher than the pump. This method is generally used for secondary water supply. Because the liquid level is higher than the pump, it is not necessary to close the pump outlet valve when starting and stopping the pump, so the check valve should be installed in the The rear of the water pump.
Whether the check valve is installed before or after the valve does not affect its function.

Precautions for installation of single plate check valve

1. The check valve is a one-way valve, so the installation position, height, and direction of inlet and outlet must meet the design requirements, and the direction of medium flow should be consistent with the direction of the arrow marked on the valve body.

2. Check the appearance before installing the check valve. The nameplate of the valve should comply with the current national standard “General Valve Marking” GB 12220. It can be used after all standards are qualified.

1. Do not allow the check valve in the pipeline to bear weight, especially the large check valve, which should have an independent support and not be affected by the pressure generated by the pipeline.

Related news /knowledge:
Accuracy requirements of Equipment installation;
Working principle diagram of swing check valve;
Current status and development of Chinese valves;
Flange telescopic butterfly valve application | advantages and disadvantages | installation instructions;

Process design of check valve

Process design of check valve:
(1) The quality control of the main body blank. All parts of this valve are forgings. The forging process is carried out

8 tilting-disc-swing-check-valve-3

8 tilting-disc-swing-check-valve-3

in strict accordance with the forging process regulations and process cards. The initial forging temperature, final forging temperature, deformation degree and deformation speed are strictly controlled, and the process regulations stipulate The cooling method performs cooling. Chemical composition analysis, mechanical property test, intergranular corrosion test, metallographic analysis of the forged product are carried out. After analysis, test and determination, they all meet the corresponding standards.

The quality of the forgings is guaranteed by ultrasonic inspection and liquid penetration inspection. The forgings are 100% ultrasonically inspected and evaluated in accordance with RCC-M requirements, and liquid penetration inspections and evaluations are performed on all surfaces of the forgings.

(2) Welding In order to improve the quality of surfacing welding, plasma argon arc welding is used for surfacing welding of the sealing surface of the valve disc and the valve seat. At the same time, in order to ensure the welding quality, the welding process used in production was re-qualified.

(3) Assemble test High-quality products not only require high-precision components, but also how to assemble these high-precision components into high-performance products. China Nuclear Su Valve has organized an assembly and commissioning team composed of multiple technicians and senior technicians with rich experience and excellent technology. It is responsible for valve assembly, commissioning and testing. It has formulated the cleaning process and assembly process of parts and components. Strictly check and keep improving during the commissioning to ensure the successful assembly and commissioning of the valve. Various performance tests have been carried out, and all indicators meet the requirements of the design task book.

(4) Process inspection has prepared a quality plan for the valve to ensure that the valve has been quality controlled from raw materials, blank input, machining, welding, heat treatment, non-destructive testing, cleaning, assembly, factory testing and various type tests, and has been verified Recognition and on-site witness by the Second Industrial Research and Design Institute.

Butterfly double flap check valve is suitable for high-rise building water supply pipe network, pipe network with

double-wing-check-valve-3

double-wing-check-valve-3

certain chemical corrosive medium, pipe network with limited installation space, and also suitable for sewage pipe network.

The lift-type silent check valve is suitable for pipe networks with high quality requirements for water supply and drainage projects; pipe networks with relatively high pressure requirements (PN2.5Mpa); it can be installed at the outlet of the pump and is an economical and practical waterproof hammer check valve.

The lift-type silencing check valve is suitable for water supply and drainage systems and high-rise building pipe networks. It can be installed at the outlet of the pump. With a slight structural change, it can be used as a suction bottom valve, but it is not suitable for sewage pipe networks.

The horizontal check valve is suitable for diving, drainage and sewage pumps, especially for sewage and sludge

6 single-plate-swing-check-valve-2

6 single-plate-swing-check-valve-2

systems.

Swing rubber check valve is suitable for domestic water pipe network; but not suitable for sewage with a lot of sediment

Swing single check valve is suitable for water supply system, petroleum, chemical industry, metallurgy and other industrial sectors. It is most suitable for places with installation space restrictions.

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