How to choose a valve?

For water pumps, butterfly valves should be given priority, as they have a lower pressure drop compared to globe valves

For large diameters, butterfly valves are preferred; for diameters up to 200, gate valves can be used.

For economy, choose a butterfly valve; for performance, choose a globe valve.

Ball valve, gate valve； Ball valves have good shut-off performance

It doesn’t seem to be a mandatory requirement, right? However, butterfly valves are much cheaper in certain regions compared to other types of valves

I don’t understand it that well, but I do know there are many factors to consider regarding a pump’s inlet and outlet, such as negative pressure and backflow! Check out the information related to pumps. The valves were not chosen randomly.

 3.4.6 Valves used in water supply pipelines should be selected according to the application requirements following these principles:  1 When it is necessary to regulate flow rate and water pressure, control valves or globe valves are recommended；  2. For areas where low water flow resistance is required, gate valves, ball valves, and hemispherical valves are preferred ；  3 In locations with limited installation space, butterfly valves and ball valves are recommended ；  Check valves shall not be used in pipe sections where the 4 water flows need to flow in both directions ；  For water pumps with a diameter of 5, it is advisable to use a multi-functional valve on the outlet pipe. (This is included in general design manuals and is part of the specifications.)  3.4.7 Check valves shall be installed on the following sections of water supply pipes:  1 The inlet pipes that connect directly to the urban water supply network and lead into residential complexes or buildings ；  Note: Pipe sections equipped with check valves do not require additional check valves.  2 On the water inlet pipes of sealed water heaters or water-using equipment ； (Determined to meet the requirements for the check valve setup)  On the outlet pipe of Pump 3 ；  On the outlet pipe sections of water tanks, water towers, and elevated water reservoirs that share a single pipe for 4 inlet and outlet pipes. (Meet the requirements for backflow prevention; hydraulic conditions are necessary.)  3.4.8 The type of check valve to be selected should be determined based on factors such as the installation location of the check valve, the water pressure before the valve, the requirements regarding its sealing performance when closed, and the magnitude of water hammer generated upon closure. It shall also meet the following requirements:  1 In locations where the water pressure before the valve is low, swing-type, ball-type, and plug-type check valves are suitable choices ；  2 For areas where tight sealing performance is required after closure, check valves equipped with closing springs are advisable ；  3 It is necessary to weaken the areas prone to water hammer; quick-closing noise-reducing check valves or slowly-closing check valves equipped with damping devices are suitable choices ；  The disc or plug of the 4 check valves should be able to close automatically under the action of gravity or spring force ；  The check valve should open automatically when the minimum pressure in the pipeline system or the lowest water level in the tank is reached. (As stated in general technical manuals)  6 When the water inlet and outlet for the water tank or water tower are through the same pipe, check valves of the swing-type or lift-type type, which generate significant vibration, should not be used. (Architectural environment integration)