Watts 0590716 Air Vent 20" WC rating on your

20" WC rating on your existing switch to ensure proper pressure differential matching

Reliable Performance: Built to withstand industrial-grade gas environments including natural gas

This assembly is typically used when the control circuit requires additional resistance to match the electrical characteristics of specific 36C valve and pilot combinations

The Rheem-Ruud 68-21812-04 Fiberglass Gasket is a genuine OEM replacement part engineered for critical sealing applications within high-efficiency HVAC systems

Lower ports typically require different diameters

Watts 0590716 Air Vent 20" WC rating on yourThe Watts 0590716 (Series FV 4M1) is a heavy duty 1 4 inch automatic air vent designed for high performance hydronic heating systems. As the direct replacement for the discontinued 590715, this valve is engineered to purge entrapped air from hot or cold water distribution systems automatically. Built with a rugged brass body and cover, it features a high temperature resistant polyethylene float and a durable silicone rubber seal, making it fully