yupHome depot & lowes have them for drip irrigation and if you don't use the regular it will blow the drip regulator off the hose. Drip regulators are calibrated at a set water pressure, like 25 psi. If you put a pressure gauge after the filter you can tell when to change the cartridge.
also check out the drip irrigation section of www.rainbird.com.
my system is very simple. I stole the idea from Repair....his is the stuff!