Hi Cheryllou,

I believe your T-30 is just rotor nozzle that fits on a pop-up sprinkler. Here is a Rainbird link that may be useful.

http://www.rainbird.com/drip/products/control/xeri-caps.htm

I hope this helps. Aloha

It sounds to me like you have the old T-Bird rotor heads in your yard, which are no longer made. I dont believe there is a way to turn off a particular T-Bird head short of capping the head off. You could replace the head with a newer model that you have the ability to turn off if you wanted to turn off that head on a temporary basis.