These compact, heavy duty, pilot operated, iron alloy (ASTM A126 Class B) Outlet Pressure regulators are suitable for Ammonia, R-12, R-22, R502 and other common refrigerants and fluids approved for use in refrigerant valves. All A4 Regulators are pilot operated using upstream pressure for the opening force and requires a minimum 0.14 bar (2 psig) pressure drop to fully open. These valves are generally ordered with close coupled strainer to prevent entrance of foreign material into the valve and the rest of the system. (See current Bulletin 00-10 for strainer information.) The fluid tempeature range for the A4 Series of Regulators is -45C to 105C (-50°F to 220°F).