The Sensus-Gas Division 143-3/4 is a precision-engineered inline regulator valve for controlling gas flow and pressure in HVAC systems. This green valve has a 3/8-inch orifice and a typical 3/4-inch intake size. Its meticulous design maintains gas pressure in the range of 6 to 14 inches of water column. The 143-3/4 valve is an essential part of gas supply lines that modifies gas flow to maintain constant pressure levels in the HVAC system.