Contact UsFakai Valve Factory Site: Yongxing Industrial Zone, Longwan District, Wenzhou City Tel: 0577-88767789
Contact: Mr. Wang Email: firstname.lastname@example.org
Ordering and Selection Instructions for Check ValvesRelease Date: September 08, 2014
In order to facilitate the user's use, our company can provide matching flanges, gaskets, connecting bolts, nuts, pipe fittings, fluid equipment and other accessories for check valves , but users need to specify when ordering. Product standards can use GB, JB, API, JIS, DIN, BS, EN, SH, HG, etc.
In order to prevent the medium from flowing back, check valves should be installed on the equipment, devices and pipelines, which are generally suitable for clean media, and should not be used for media containing solid particles and high viscosity;
When selecting a check valve for incompressible fluids , the required closing speed must first be evaluated, and the second step is to select the type of check valve that may meet the required closing speed;
When selecting a check valve for compressible fluids , you can choose a similar method to check valves based on incompressible fluids. If the medium flow range is large, the check valve for compressible fluids can use a reduction device If the medium flow is stopped and started quickly and continuously, such as the outlet of a compressor, a lift check valve is used;
Check valve purchase
- Lift check valve : Generally, vertical lift check valves should be used on horizontal pipes with a nominal diameter of 50mm; straight-through lift check valves can be installed on horizontal pipes and vertical pipes; The swing-open type has good sealing performance and large fluid resistance. It should be installed horizontally on horizontal pipes and vertically on vertical pipes.
- Swing check valve : the installation position is not limited, it can be installed on horizontal, vertical or inclined pipelines, such as on vertical pipelines, the medium flow from bottom to top;
Swing check valve should not be made into a small-diameter valve, the working pressure (PN) can reach 42MPa, and the nominal diameter (DN) can reach more than 2000mm, and the operating temperature range is -196 ~ 800 ℃;
- Butterfly check valve : unlimited installation position, can be installed on horizontal pipelines, or on vertical or inclined pipelines;
- Diaphragm check valve : Suitable for pipelines that are prone to water hammer. The diaphragm can well eliminate the water hammer when the medium is flowing backward. It is generally used on low pressure and normal temperature pipelines, especially for tap water pipelines. The working temperature of general media Between -12 ~ 120 ℃, the working pressure is ≤1.6MPa, but the diaphragm check valve can achieve a larger diameter, and the maximum DN can reach more than 2000mm;
- Float check valve : also known as ball check valve, suitable for medium and low pressure pipelines, can be made into large diameter; the housing material can be made of stainless steel, the hollow sphere of the seal can be wrapped with PTFE engineering plastic, so It can also be applied to the pipelines of general corrosive media, the working temperature is between -101 ~ 150 ℃, its nominal pressure is ≤4.0MPa, and the DN is between 200 ~ 1200;
- Slow-closing check valve : For pipelines with relatively small or no water impact when closed, slow-closing swing check valves and slow-closing butterfly check valves should be used.
- Foot valve : For the inlet pipe of the pump, a foot valve should be used. The foot valve is generally only installed on the vertical pipe of the pump inlet, and the medium flows from bottom to top;
Select according to the nominal diameter of the check valve : high and medium pressure check valve below DN50mm, vertical lift check valve and straight-through lift check valve should be selected; low pressure check valve below DN50mm, butterfly check valve should be selected Vertical lift check valve and diaphragm check valve; high and medium pressure check valve greater than DN50mm and less than 600mm, swing check valve should be used; medium and low pressure check valve with DN greater than 200mm and less than 1200mm should be selected Non-wear ball check valve; low pressure check valve with DN greater than 50mm and less than 2000mm, butterfly check valve and diaphragm check valve can be selected;