Pipe Sizing

A general rule of thumb is that you want the water to flow through the pipe at a rate of 4 to 7 feet per second.   If you size the pipe too small, the velocity goes up and you get more friction loss and also wear out the pipe faster.  If you size the pipe too big, minerals start to precipitate out and you end up with too much scaling on the inside of the pipe and building up on top of the check valves.    When looking at the charts below, pay attention to the material of the pipe (steel vs plastic).   Remember, when we pull a pump, it is our job to advise the customer as to what size pipe SHOULD be installed in order to achieve the best results, NOT just stick with the same improperly sized pipe that someone else installed years ago.   Also, keep in mind that friction is cumulative.  It's perfectly fine to set a 10 GPM pump on 1" pipe at a depth of 210' but it's not okay to set a 10 GPM pump on 1" at 420'.