Watts FV-4-1/4 Brass Float Air Vent 150 psi 240F

Brass Float Air Vent for Hydronic Systems

The Watts FV-4-1/4 is a brass float-type air vent designed for hydronic heating installations. It removes trapped air from water or glycol systems operating up to 240F and 150 psi. The unit features a polyethylene float and silicon rubber gasket for reliable sealing. It installs via a male-threaded inlet port with a single-port configuration.

Continuous Air Removal Under Pressure

The float mechanism vents air automatically as it accumulates during sustained system operation rather than only during initial fill. A condensate capacity of 2 lb per hour handles ongoing air separation in glycol applications. The brass body withstands continuous exposure to hot water and glycol mixtures at the rated temperature limit. Operation remains consistent across the full 33 to 240F range.

Low-Maintenance Thermal Performance

Brass construction transfers heat efficiently without deforming at the 240F maximum operating temperature. The polyethylene float and silicon rubber gasket maintain sealing integrity through repeated thermal cycles. No external power or control signal is required for the venting action. The transparent body allows visual confirmation of float position and water level during normal use.