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

My new Rainbird 3500 risers do not pop up properly. There are seven to a circuit and it seems the pressure can only manage 5 to pop up completely. With a little assistance and pulling one up manually, all the others pop up properly and function as they should.

The reason is (excessive blow-by) of all the heads whilst not in the fully upright position. This causes pressure loss which makes that the other heads cannot pop up properly...

As these are all new rotors I suppose that the blow-by is something that cannot be changed.

Another solution could be a 'check valve' of some kind. This I would like to install underground, connected to the PE-main tube (25"), after 5 rotors (with 5 rotors everything still works fine). This valve should be closed and only when the pressure is high enough and the first 5 rotors work properly, should this be opened to also include the last 2 rotors.

Questions:

1. Does all this make sense?

2. Which exact type of valve would I need? This valve should be adjustable to be set to the correct pressure at which it should open.