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Requirements for the selection and piping of water pumps in pipelines: To improve the suction performance of water pumps, the suction pipeline of the pump should be as short as possible, with as few bends as possible (elbows should preferably have a large radius of curvature), in order to reduce pipeline resistance losses. To prevent cavitation in the pump, gas accumulation in bulged sections of the pump’s suction pipeline should be avoided as much as possible; if this cannot be avoided, an exhaust valve with a diameter of DN15 or DN20 should be installed in those bulged sections. When the pump’s suction pipe is vertical, if a reducer is used on the suction pipe, an eccentric reducer should be employed to prevent the formation of air pockets. To prevent the forces and moments generated by the weight of pipes and valves, as well as pipe thermal stresses, from exceeding the maximum allowable external loads at the pump’s inlet and outlet, pipe supports must be installed on the pump’s suction and discharge pipes. The maximum allowable load at the pump outlet shall be provided by the pump manufacturer. For pumps with vertical inlet or vertical outlet, in order to reduce the force acting on the pump outlet, a pipe support must be installed above the outlet; its horizontal position should be as close to the outlet as possible. The pipes can be supported using the longitudinal beams of the pipe rack, which is why pumps are often placed beneath such pipe racks. When transporting liquids with a density of less than 650 Kg/m³, such as liquefied petroleum gas and liquid ammonia, the suction pipeline of the pump should have a slope of 1/10 to 1/100 leading toward the pump, so that the gas generated by vaporization can return to the suction tank and cavitation in the pump can be avoided. At the inlet of a single-suction pump, it is advisable to install a section of straight pipe with a length of about 3 times the inlet diameter. For double-suction pumps, in order to avoid cavitation in two-way suction horizontal centrifugal pumps, the double-suction pipes must be arranged symmetrically to ensure even flow distribution on both sides. Vertical pipes are connected directly through elbows, but the axis of the pump must be perpendicular to the plane in which the elbow is located. At this point, the inlet piping is required to be as short as possible, with elbows connecting the reducers and then the inlet flange. Under other conditions, there should be a straight pipe section of at least 3 times the pipe diameter in front of the pump inlet. The area between the cut-off valve and the check valve at the pump outlet is drained using a drain valve. When the pipe diameter is larger than DN50, a drain valve can also be installed by drilling a hole in the valve cover of the check valve. For pumps of the same specification, the inlet and outlet valves should preferably be at the same elevation. The weight of the valves on the inlet and outlet pipelines of non-metallic pumps must not be borne by the pump body; pipe supports should be installed to prevent damage to the pump body as well as twisting of the pipelines ahead of and behind the valves when they are opened or closed. The steam reciprocating pump’s exhaust pipeline should have as few bends as possible; drainage pipes should be installed at locations where condensation may accumulate, and silencers should be fitted in cases where there is a large amount of venting. A condensate drain pipe should be installed on the steam inlet pipeline in front of the steam inlet valve to prevent water hammer from affecting the cylinder. Steam reciprocating pumps generally experience significant vibration during operation, and the pipelines connected to the pump should be properly secured. When the distance between the center line of the pump outlet and the center line of the pipeline column is greater than 0.6 m, the swing check valve on the outlet pipeline should be placed in a horizontal position; in this case, it is not allowed to install a drain valve on the valve cover. When the pipelines are placed above the pump and motor, they must have sufficient height so as not to interfere with the lifting operations of the lifting equipment. Pipelines carrying corrosive liquids should not be installed above the prime mover equipment. The clear distance from the bottom of the pipelines in the lower part of the pipe tray to the floor should not be less than 4 m, in order to meet the requirements for maintenance. When the pipeline is placed above the pump body, the clear height from the bottom of the pipeline to the ground should be no less than 2.2 m.