Irritrol 100P1.5 1.5" Electric 100 Series Valve with Flow Control. The Irritrol 100P1.5 1.5" 100 Series Valve is an excellent example of a good valve getting better. Tracing its origin to the highly popular Century Series, the 100 Series delivers reliable performance with a host of enhanced features. Offered in a globe/angle configuration with sizes ranging from one to three inches, the 100 Series features a pressure range of 20-220 psi, optional modular pressure regulation, stainless steel metering, internal and external bleed, a nylon-reinforced EPDM double-beaded diaphragm and an anti-contamination design for dirty water applications (available on all 102 Models).