Spring Check Valve
Spring loaded check valves prevent reverse flow and ensure one flow direction. They have one single inlet and one single outlet that can only be used in the correct orientation for proper functionality. It is called a non-return valve or one-way valve.
The valve prevents back flow by utilizing a spring or back pressure to close the valve. The valve is often used in applications that have no back flow as even the slightest possibility of back flow may damage the equipment or contaminate the media upstream. The stainless steel material of the valve provides excellence in corrosion resistance. |
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What are spring check valve
1. What is a spring check valve?
Check valve requires a pressure differential to function properly and flow moves from high pressure to low pressure. Therefore, the high pressure on the inlet side when higher than the cracking pressure will allow flow to move through the check valve by overcoming the spring strength. They are simple to understand and install due to the reliability and durability.
Check valve requires a pressure differential to function properly and flow moves from high pressure to low pressure. Therefore, the high pressure on the inlet side when higher than the cracking pressure will allow flow to move through the check valve by overcoming the spring strength. They are simple to understand and install due to the reliability and durability.
It comes with two types of sealing and there are metal seats and soft seats.
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- Metal seats valves are able to withstand high temperatures, working pressure and severe service conditions. A metal seat endures severe flashing, abrasive process fluid, hydraulic shock and high temperature up to 537°C (1,000°F). They are applicable in high erosion or corrosion applications. However, it is easy to leak as it provides relatively poor sealing performance in between metal to metal.
2. What does cracking pressure of the valve mean?
Cracking pressure is the minimum upstream inlet pressure where a normally closed check valve requires to open and fluid starts to flow through. When the inlet pressure meets the cracking pressure, the spring inside the valve will open to allow flow of the body in one direction and blocking the reverse flow direction. The standard cracking pressure is either 0.5, 1.0 or 2.0 bars and the manufacturer can customize it during production. The different cracking pressure can be customized upon request.
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Technical specifications for spring check valves are:
The spring forces the disc to close the orifice when the inlet pressure drops below the cracking pressure. The only drawback is if the valve needs to be inspected or undergo maintenance and repairs, the valve needs to be completely removed from the pipeline for the procedures to be conducted.
- Material for chemical compatibility
- Minimum cracking pressure
- How quickly the check valve closes
- End connection options
- Pressure drop across the valve when it is completely open
The spring forces the disc to close the orifice when the inlet pressure drops below the cracking pressure. The only drawback is if the valve needs to be inspected or undergo maintenance and repairs, the valve needs to be completely removed from the pipeline for the procedures to be conducted.
3. Can a spring check valve be installed horizontally?
Spring check valves can be installed in horizontal or vertical position in the pipeline with condition that the flow is running upwards. Upon installing the check valve, a label of flow direction that allows the valve to perform can be found stamped on the valve body. The flow arrow is labelled on the body to make sure the valve is installed correctly in position.
Mounting for vertical installation is critical. Check valves are frequently used as a great solution to prevent back flow that causes damage to equipment. The main selection criteria to consider are as per below:
3.1 Design type: Determine on the media and application.
3.2 Connection: Ensure the valve connection to have a good sealing upon installation.
3.3 Size: Size determines the pressure and flow rate that the valve can handle. Therefore, select the correct size to increase system efficiency.
3.4 Material: Ensure the material does not contaminate the media and it can withstand the media characteristics.
Spring check valves can be installed in horizontal or vertical position in the pipeline with condition that the flow is running upwards. Upon installing the check valve, a label of flow direction that allows the valve to perform can be found stamped on the valve body. The flow arrow is labelled on the body to make sure the valve is installed correctly in position.
Mounting for vertical installation is critical. Check valves are frequently used as a great solution to prevent back flow that causes damage to equipment. The main selection criteria to consider are as per below:
3.1 Design type: Determine on the media and application.
3.2 Connection: Ensure the valve connection to have a good sealing upon installation.
3.3 Size: Size determines the pressure and flow rate that the valve can handle. Therefore, select the correct size to increase system efficiency.
3.4 Material: Ensure the material does not contaminate the media and it can withstand the media characteristics.
4. What is the difference between a spring check valve and a swing check valve?
Both valves function in the same way to ensure one flow direction with no reserve flow. Swing check valve operates with a disc and spring check valve operates with a spring. The swing check valve has a disc inside that covers the opening of the valve. The disc is attached to a hinge, so that it can swing open or close when fluid hits the disc.
Both valves function in the same way to ensure one flow direction with no reserve flow. Swing check valve operates with a disc and spring check valve operates with a spring. The swing check valve has a disc inside that covers the opening of the valve. The disc is attached to a hinge, so that it can swing open or close when fluid hits the disc.
The spring stays close when there is no flow in the correct direction. It is easy to get the swing and spring check valve confused and it comes with different purposes. Both valve bodies have an arrow sign to show the flow direction as it is the most important thing when using a check valve. Swing check valves are forced close by backflow and while spring check valves are closed by default. The default standard for spring check valve is it requires cracking pressure to push the spring and allow fluid through the valve.
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