Check valve should determine the appropriate size, the valve provider must provide the selected size of the data, so that you can find the valve when the valve is fully open at a given flow rate of the size of the valve size. Insulated check valve Insulated check valve is practical for easy to produce water hammer on the pipeline, the barrier can be very good to eliminate the media counter-current occurred when the water hammer, it is also commonly used in low-pressure room temperature pipe, especially useful Water pipe, as usual medium matter temperature between -12--120 ℃, things pressure <1.6MPa, but the gap check valve can do larger caliber, DN maximum can reach 2000mm above; ball check valve Ball check valve is used in medium and low pressure pipe, can be made of large diameter; spherical check valve housing material can be made of stainless steel, the seal of the hollow sphere can be wrapped Teflon engineering plastics, so as often corrupt The medium of the pipeline can also be applied, things temperature between -101--150 ℃, the nominal pressure ≤ 4.0MPa, nominal pass through the category between 200-1200; otherwise, to deal with non-compressive fluid only The first step in the selection of the check valve is to evaluate the required closing rate. The second step is to select an example of a check valve that is approximately satisfactory with the closing rate. With a check valve for compressible fluids, The option of using the same essentials of a non-return valve for compressible fluids can be used to select a check valve for compressible fluids that uses a decelerator if the media activity is large and if the media flow is stopped quickly for some reason And start, such as the compressor outlet, then the use of landing check valve. Check valve should determine the appropriate size, the valve provider must provide the selected size of the data, so that you can find the valve when the valve is fully open at a given flow rate of the size of the valve size.