SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

While I have no practical experience with pumps, it would make logical sense to have a filter before a pump to keep stuff out of the pump. I don't see how filtering the water could ever harm a pump. About the only caviot for the pump is to make sure enough junk doesn't build up in the filter that the pump could run dry. The only caviot for the filter would be to make sure it is rated for the constant pressure it will be under. That doesn't mean if you have a water system with a static pressure of 50psi that you can use a filter rated for 50psi. Any plumbing system is going to have pressure spikes as water starts and stops and other things happen in the system. So as an example, I would think that a filter would have to be rated for a MINIMUM of 150psi before installing it in a system that has a static pressure of 70psi or less. Even then, its questionable in the long run what might happen to it. As an example, plumbing codes dictate that if you use PVC, it must be burried under ground. Yet 1" Sch 40 PVC has a max operating pressure of 270psi (and a bursting strength of 1440psi). For exposed applications (such as in a basement) PVC can not be used, and instead copper is rated for use. But copper has an operating pressure rating of about 500 psi.