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The pipe size is selected, not calculated


Many friends are asking how to calculate the diameter of water pipe... It's really hard to say clearly in a few words.

In the pipeline system, how to select the pipeline... Pay attention to whether the selection is calculated.

You must confirm how much traffic there is at your end... It's actually very simple... You don't need to calculate the traffic of the device. Just ask your users.

You can add up the traffic at the end as many as you have... So there is traffic.

You can find the recent flow data like you according to the following table... The corresponding pipe diameter is what you want.


Note: the top row is the flow rate... A large piece of data in the middle of the above table is the flow... The left row is the nominal diameter of the water pipe... Q: which one do I choose for so many flow rates... Don't worry... Look at the table below (there is a difference between open system and closed system)


The above table is worth saving... No matter where you go in the future, others ask you how big the pipeline has to be... You ask the flow, open the table and you can tell him

But you should note that the diameter of the suction pipe shall not be less than the diameter of the pump inlet. The suction pipe diameter of centrifugal pump is generally 1 ~ 2 grades larger than the pump inlet diameter, and the suction pipe diameter of reciprocating pump is generally 1 ~ 3 grades larger than the pump inlet diameter.

The reasons are as follows:

1) Make the flow at the suction inlet meet the design requirements, prevent pump evacuation and protect the pump impeller (for the same reason, the suction pipe diameter of centrifugal pump is generally not less than the discharge pipe diameter of pump).

2) The suction pipe diameter is large, the flow rate is small at the same flow rate, and the flow loss is reduced, which is conducive to avoiding cavitation erosion (for the liquid with transmission density less than 650kg / m3, the suction pipe of the pump shall have a slope of 0.01 ~ 0.1 towards the pump, so as to return the gas generated by gasification to the suction tank to avoid cavitation erosion of the pump. When the liquid in the suction pipe of the pump is close to the bubble point, the suction pipe of the pump should be low slope to the machine pump).

The discharge pipe of the pump is provided with a flare, and the section of the flow channel is enlarged, which can convert the dynamic head of the high-speed fluid in the pump into a static head, that is, into the head of the pump for further pressurization. For pumps with small head, small flow and small diameter, under the requirements of process permission, the suction pipe and discharge pipe can also be without reducer.