4.3. Valves and Fittings
1) Elbows should be no closer than 350mm to the inlet. Do not install 90° elbows directly into the pump
inlet/outlet. Joints must be tight.
* The pump inlet/outlet union size: optional with 48.5/50/60.3/63mm
2) Flooded suction systems should have gate valves installed on suction and return line for maintenance;
however, the suction gate valve should be no closer than seven times the suction pipe diameter as
described in this section.
3) Use a check valve in the return line where there is a significant height between the return line and the
outlet of the pump.
4) Be sure to install check valves when plumbing in parallel with other pumps. This helps prevent reverse
rotation of the impeller and motor.
4.4 Check before initial startup
1) Check whether pump shaft rotates freely;
2) Check whether power supply voltage and frequency conform to the nameplate;
3) Facing the fan blade, the direction of motor rotation should be clockwise;
4) It is forbidden to run the pump without water.