You are not logged in.

Dear visitor, welcome to SPRINKLER TALK FORUM - You Got Questions, We've Got Answers. If this is your first visit here, please read the Help. It explains how this page works. You must be registered before you can use all the page's features. Please use the registration form, to register here or read more information about the registration process. If you are already registered, please login here.


New Member


Monday, July 26th 2010, 1:47pm

Different pipes sizes in same run....

Hello... This might seem like a stupid question but I am going to ask.... I am attempting to refurnish a sprinkler system that installed in my new home and have found that in one of the runs does not have the water coming from the six (6) heads that I think it should. I have found out that while is starts out using 1/2 inch PVC there is about a seven foot section in the center of the run that is 3/4 inch PVC and then goes back to being 1/2 inch. To me this seems like it should be a problem but in reading it seems that nothing in the hydromechanics of sprinkler systems is what it would seem.

Thank you for any insight you might give. Stan


Supreme Member


Monday, July 26th 2010, 5:34pm

In an irrigation system... bigger pipes are better because it means less pressure losses due to friction between the water and the pipe wall.

The only negatives to larger pipes is that generally, larger means more money, and of course you would lose more water if the pipes drain between each use.

And mixing and matching doesn't hurt anything provided your system is designed to handle the smallest pipe.

As a general comment, from what I've read, you generally don't want to use 1/2" pipe in an irrigation system unless it's for feeding drip irrigation or its the last few feet of pipe suppying water to a single spray. The general reasons include typically huge pressure losses and higher likelyhood of water hammer (because the smaller the pipe, the faster it has to go).

Rate this thread