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Pool Pipe Sizing

Pool pipe sizing is a major consideration when determining the proper pump size for your pool. 
The larger the diameter of the pipe, the more water can flow through it.

As a general rule, the velocity of the water through the pipe should not exceed 6-7 feet per
second.  Consult pipe sizing tables or the following chart for details.

1.5 Inch Pipe

44 GPM

2.0 Inch Pipe

78 GPM

2.5 Inch Pipe

120 GPM

3.0 Inch Pipe

160 GPM

Add up the total capacity feeding the pump at any one time and
you will find out the maximum flow rate that you should look for in a pump.  

In the diagram at the left, the system has two inch piping. 
While there are three pipes coming from the pool, there is only one coming from the spa.  That fact limits the maximum flow to 78 gallons per minute.  The
flow on the return side is also limited to the same 78 gallons per minute.  

In reality, it is not as dangerous to exceed the capacity of
the piping slightly on the return side, the pipe sizing MUST be correct on the intake side or the pump will not operate properly.




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a FREE PUMP SIZE recommendation specifically
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