The selection criteria for check valves involve many aspects, as follows:
◉ High, medium and low pressure selection
(1) For high and medium pressure check valves, when the nominal diameter is less than DN50mm, it is recommended to use a vertical lift check valve or a straight lift check valve.
(2) For low pressure check valves, when the nominal diameter is less than DN50mm, it is appropriate to choose a butterfly check valve, a vertical lift check valve or a diaphragm check valve.
◉ Preferred types for different diameters
(3) When the nominal diameter of the high and medium pressure check valve is between DN50mm and 600mm, a swing check valve is recommended.
(4) For medium and low pressure check valves, when the nominal diameter is greater than DN200mm and less than DN1200mm, a wear-free ball check valve would be an ideal choice.
◉ Selection under specific conditions
(5) If the nominal diameter of the low-pressure check valve is in the range of DN50mm to 2000mm, then butterfly check valves and diaphragm check valves are more suitable.
(6) In pipelines that require the reduction or avoidance of closing water hammer, slow-closing swing check valves or slow-closing butterfly check valves should be selected.
(7) For water pump inlet pipelines, foot valves are the appropriate choice.
