Centrifugal pump installation
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When installing a centrifugal pump, what is the minimum length of straight pipe required at the suction inlet?
Horizontal suction requires a certain length of straight pipe; 800 MM is generally sufficient, as this ensures smooth flow of the fluid before it enters the pump
Additional note: The length of the straight pipe is related to its diameter; generally, it should be more than 300 and at least 4 times the diameter of the pipe. That’s what it seems to be; I hope experts can correct me if I’m wrong
Please refer to HG/T20549.5 Specifications for the Design of Pipeline Layout in Chemical Plant Equipment, Section 7: Piping for Pumps. 7.3.2 Pump inlet piping 2. To prevent flow deviation and swirl currents from reducing the pump’s performance, the piping requirements are as follows: 1) If there is a horizontally arranged elbow at the single-sided suction inlet, a straight pipe section with a length greater than three times the pipe diameter should be provided between the suction inlet and the elbow. 2) The arrangements at the bilateral inlets shall be as specified in item 1 of paragraph 2 of section 7.3.2 of this chapter, but the length of the installed pipe section shall be at least seven times the pipe diameter. 3) When the straight pipe section is not long enough, rectifying or guiding plates should be installed inside the short pipe, or the piping layout should be changed.
For details, refer to HG/T20549 Specifications for the Design of Pipeline Layout in Chemical Plant Facilities
Does this also require a corresponding medium? ?
The inlet prevents flow pattern changes such as deflection and vortices from affecting the impeller; straight pipe sections should be used as much as possible, with fittings such as elbows and tees avoided. Also pay attention to the pressure drop in the inlet pipeline; the lower it is, the better, as this reduces the need for pipe fittings.
The centrifugal water pumps used in our factory have inlet pipes under pressure, at around 0.4 MPa – will the phenomenon mentioned on the 7th floor really occur?
Brother on the 8th floor, it’s okay. If it’s already installed, then there’s no need to worry about it. It’s indeed something that should be taken into consideration when designing.
I remember that the diameter of the suction pipe of a centrifugal pump should be larger than that of the outlet pipe.