China Check Valve Manufacturer

Check Valve

NINGBO SALVADOR is a check valve supplier, providing five types of check valves: single union ball check valve, double union ball check valve, flap check valve, wafer check valve and foot valve. We manufacture our valves in three materials: PVC, CPVC and PPH. These are suitable for use in plastic piping systems such as PVC CPVC PPH to prevent various problems such as pipe backflow, contamination, damage and leaks.
PVC Single Union Ball Check Valve

PVC Single Union Ball Check Valve

CPVC Single Union Ball Check Valve

CPVC Single Union Ball Check Valve

PPH Single Union Ball Check Valve

PPH Single Union Ball Check Valve

PVC Spring Type Foot Valve

PVC Foot Valve

PVC True Union Ball Check Valve

PVC True Union Ball Check Valve

CPVC True Union Ball Check Valve

CPVC True Union Ball Check Valve

PPH True Union Ball Check Valve

PPH True Union Ball Check Valve

PVC Flange Type Ball Foot Valve

PVC Flange Type Ball Foot Valve

PVC Flange type True Union ball check valve

PVC Flange type True Union ball check valve

PVC Flange type Single Union ball check valve

PVC Flange type Single Union ball check valve

PVC Swiming Check Valve

PVC Swiming Check Valve


All You Need To Know About Check Valves

Check valve, often termed as a non-return check valve or a one-way check valve by manufacturers, serves a crucial role in preventing the reverse flow of media. These valves function automatically, eliminating the need for manual operation or intervention through actuators.

Check valves become indispensable when there is a necessity to avert backflow or mitigate the risks of medium contamination leading to emergency damage. This underscores the importance of ensuring that the inlet and outlet are correctly oriented to enable the check valve to operate effectively.

This article delves into key aspects of check valves, encompassing their diverse applications, operational mechanisms, factors to ponder when making a purchase, and the various classifications that categorize check valves.

Common Uses of Check Valves

Check valves, renowned for their non-return functionality, find extensive applications primarily focused on preventing backflow concerns. These include:
  1. Sewage Systems: In sewage lines, especially where the risk of upstream contamination is a concern, check valves play a pivotal role in maintaining fluid direction.

  2. Reverse Osmosis Filters: Check valves are integral components in reverse osmosis filters, ensuring that water flows in the intended direction without backflow.

  3. Vacuum Sealing: Applications requiring vacuum sealing benefit from check valves, as they help maintain the desired pressure conditions.

  4. Equipment Protection: Check valves are employed in various applications to safeguard equipment against potential damage caused by unwanted backflow.

Check Valve Types By Design

Classification based on valve structure and check method

Swing Check Valve

Swing Check Valve is a common type of check valve, named after its unique flipping wing or gate.

There is a door wing inside the flap check valve, usually flat, which is installed inside the valve body. The door wings are free to rotate around their axes to control the flow of fluid.
These valves are relatively simple in design and usually have few moving parts, so they are relatively easy to maintain.
The flap check valve can quickly respond to changes in the flow direction of the fluid and close quickly to prevent backflow.

Swiming Check Valve
Swiming Check Valve

Wafer Check Valves

The wafer check valve has a compact design, and both ends need to be installed on the pipeline with flanges during installation. During forward flow, the pressure of the fluid lifts the disc from its seat, allowing fluid to flow freely through the clip-on check valve. During reverse flow, the reverse pressure of the fluid forces the disc to fit against the valve seat, preventing reverse flow.

Wafer Check Valve
Wafer Check Valve

Ball Check Valve

The valve body of the ball check valve contains a ball core inside, which moves in a fixed guide rail, and the rubber with good elasticity is attached to the outside to ensure the sealing and reduce the damage to the pipeline system during the valve closing process.

The ball check valve can quickly close to prevent reverse flow. When the fluid attempts to flow in the opposite direction, the valve ball will be pushed to the closed position by the pressure of the fluid, preventing backflow.

Some ball check valves have a spring that helps the ball close more quickly for reliability.

True Union Ball Check Valve
True Union Ball Check Valve

Foot Valve

The Foot valve is usually designed for various water pumps and pipeline systems, and its main function is to prevent the water in the pipeline from flowing back into the water source or well after the water pump stops working. This can keep the suction pipeline full of water, in order to reduce air intake and improve suction efficiency when restarting the water pump.

Some bottom valves have filter screens or screens to prevent particles or impurities from entering the water pump system and protect the water pump from damage.

Foot Valve
Foot Valve

How Do Check Valves Work?

Check valves use pressure differentials in the pipeline to automatically open and close the valve. When there is sufficient pressure in the pipeline to the inlet end of the valve, the valve opens automatically. When there is sufficient pressure at the outlet of the valve, the medium will push the valve core and automatically close the valve.

Check valves utilize the flow direction and pressure differential of fluid to automatically control the opening and closing of the valve, ensuring that fluid can only flow in one direction, thus preventing backflow. This automatic operation makes check valves particularly suitable for applications where preventing the reverse flow of media is essential, such as preventing contaminants from entering a water supply system or protecting equipment from the adverse effects of backflow

Open State: When fluid flows from the inlet side to the outlet side of the check valve, fluid pressure pushes the valve, automatically opening it. This allows fluid to pass freely through the valve without creating resistance.

Closed State: Once fluid attempts to flow in the reverse direction, the valve’s leaf or piston is pushed into the closed position by the reverse pressure of the fluid. This rapidly seals off the pipeline, preventing further backflow.

Normal Flow Direction: When fluid flows as per the designated direction defined by the check valve’s design, the valve remains in the open state, permitting fluid passage.

Prevention of Reverse Flow: If fluid attempts to reverse its course, the valve promptly closes, preventing backflow.

Why Choose Check Valves?

Preventing backflow

The most obvious reason is that check valves can effectively prevent backflow of fluid in the pipeline. This is important to prevent pollutants, waste water or other media from entering the water supply or other equipment where backflow is undesirable.

Protect equipment

Check valves prevent reverse flow from damaging equipment. In some cases, reverse flow may lead to overstressing or other adverse effects on equipment.

Maintaining System Pressure

In some systems, check valves help maintain the normal operating pressure of the system. If reverse flow occurs, the pressure in the system may drop, affecting supply or operating efficiency.

Avoiding Leaks

By preventing backflow of media, check valves can reduce or avoid leaks in piping systems. This is important to reduce resource waste, maintenance costs and environmental impact.

Ensure system stability

In some industrial processes, such as chemical, oil and gas production, the flow direction of media must be precisely controlled to maintain system stability and efficiency. A check valve ensures that the medium flows in the intended direction.

Regulations and Standards Requirements

In some applications, regulations and standards require the installation of check valves to ensure system safety and compliance.


Considerations When Purchasing Check Valves

several critical factors should be taken into consideration:

#1.Application Requirements: Start by identifying the specific application where the check valve will be used. Consider factors such as the type of fluid, pressure levels, temperature range, and flow rate requirements. Different types of check valves are suitable for different applications.

#2.Valve Types: Familiarize yourself with the various types of check valves available, such as swing check valves, ball check valves, and lift check valves. Choose the type that best suits your application’s needs.

#3.Material Compatibility: Select materials that are compatible with the fluid being handled to ensure long-term resistance to corrosion or damage. Common materials include cast iron, stainless steel, brass, and plastics.

#4.Size Matching: Ensure that the chosen check valve’s size matches the dimensions of your pipeline system to guarantee effective operation.

#5.Pressure Rating: Understand the maximum operating pressure of your pipeline system and choose a check valve with a suitable pressure rating. Check valves come in different pressure ratings to accommodate varying needs.

#6. Temperature Range: Verify that the selected check valve is suitable for the temperature conditions of your application. Different materials and designs are intended for specific temperature ranges.

#7. Safety Standards: Check if the check valve complies with international or regional safety and quality certification standards. This ensures that the product meets performance and safety requirements.

#8. Reputation: Opt for a reputable manufacturer or brand known for producing high-quality check valves and providing reliable after-sales support.

#9. Price Comparison: Prices for check valves may vary among suppliers and brands. Conduct price comparisons while considering the balance between performance and cost.

#10. Expert Consultation: If you’re uncertain about the best type of check valve for your application, seek advice from professionals or valve engineers.

#11. Warranty and Support: Understand the warranty terms for the check valve and the manufacturer’s policies regarding after-sales service and support.

Check Valve Types By Material

Stainless steel (Stainless Steel) check valve:
Advantages: Stainless steel has excellent corrosion resistance and is suitable for various media, including corrosive liquids. It is resistant to high temperature and low temperature, long life, and has high strength.
Disadvantages: high cost, relatively heavy. Not suitable for strong oxidizing media such as chlorine gas.

Cast iron (Cast Iron) check valve:
Advantages: Cast iron check valves are relatively inexpensive and suitable for general industrial and municipal applications.
Disadvantages: poor resistance to corrosive media, easy to rust. heavier.

Brass (Brass) check valve:
Pros: Brass has good corrosion resistance and is suitable for cold water, hot water, and general gas applications. Corrosion resistance is relatively good, and the manufacturing process is easy.
Disadvantages: higher cost, not suitable for high pressure and high-temperature applications.

Alloy Steel (Alloy Steel) check valve:
Advantages: Alloy steel has high strength and good corrosion resistance, suitable for high temperature, high pressure, and corrosive media.

Disadvantages: high cost and relatively heavy weight.

Plastic (Plastic) (such as PVC, CPVC, PPH) check valve:
Advantages: Plastic check valves are suitable for general purposes, are relatively inexpensive, will not rust, are suitable for corrosive media, and are light in weight.
Cons: Not suitable for high temperature and high-pressure applications.

PVC Check Valve
PVC Check Valve

Nickel Alloy Check Valve:
Pros: Nickel alloys have excellent corrosion resistance and high-temperature performance for applications in extreme environments.
Disadvantages: high cost, usually used for special requirements.

Precautions for installing check valves

The correct installation of the check valve is a necessary condition for ensuring the normal operation of the pipeline.

#1.Proper Orientation: Check valves often need to be installed in a specific orientation to ensure they open for forward flow and close for reverse flow. Make sure that the flow direction marked on the valve matches the actual flow direction of the pipe.

#2.Avoid Water Hammer Effect: A water hammer is a shock wave caused by a sudden stop or change in the direction of fluid that can damage valves and piping. Install a pressure-reducing valve or relief device near the check valve to reduce the effect of the water hammer.

#3.Proper Size: Select the correct size check valve and make sure it matches the size of your piping system. Incorrect sizing may prevent the valve from functioning properly or cause flow restriction.

#4.Maintenance and Cleaning: Before installation, make sure the check valve and the inside of the piping are clean and free of debris or deposits. Clean and maintain the check valve regularly to ensure it is functioning properly.

#5.Support and Securing: Properly support and secure the check valve to prevent it from vibrating or loosening. This helps prolong the life of the valve and ensures its stable operation.

#6. Avoid air ingestion: Ensure that the piping downstream of the check valve remains full of liquid at all times to prevent air ingestion. This helps prevent air pockets from forming in the pipe, which could affect the performance of the valve.

#7.Regulations and Standards Compliance: Follow applicable regulations and standards to ensure that check valves are installed in compliance, especially in areas involving water supply, wastewater treatment and industrial processes.

#8. Pressure Test: Perform a pressure test prior to start-up to ensure the check valve is functioning properly and leak-free.
Antifreeze measures: If installed in a cold area, take appropriate antifreeze measures to prevent the check valve from freezing and damage.

#9.Safety: When operating the check valve, ensure that the operator understands the working principle of the valve and safe operating procedures

The difference between Foot Valve and Check Valve

The Foot Valve is a kind of Check Valve, and both the check valve and the bottom valve are important equipment used in the pipeline system. But they differ significantly in design, function, and application.

Check valve:

Check valves are usually installed anywhere in the pipeline to prevent the medium from flowing backward in the pipeline. Can be installed in horizontal or vertical piping, depending on the specific need to prevent backflow.
Foot Valve:

A foot valve is usually located at the bottom of the suction pipe, directly connected to a water source such as a well or tank. They must be installed vertically to ensure that the pump can effectively draw water and prevent the water in the pipe from flowing back to the source.
Application fields:

Check valve: suitable for various piping systems, including industry, municipal water supply, sewage treatment, chemical industry, heating and cooling, etc.
Bottom valve: mainly used in water pump systems, such as municipal water supply, agricultural irrigation, well water extraction, etc.

PVC Socket Foot Valve

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