Danfoss SFV 20 back-pressure-dependent safety relief valve, store code 2416+294, set pressure 22 bar g (319 psig), supplied with a pressure-setting certificate. SFV 20 and SFV 25 are standard, back-pressure-dependent safety relief valves in angle-way execution, designed to protect pressure vessels and other components against excessive pressure in industrial refrigeration plant. On a rise above the set pressure the valve starts to open, is fully open before the pressure is 10% above set pressure, and is fully closed again before the pressure falls 10% below set pressure (DIN 3320 characteristic). The housing is special steel approved for low-temperature operation; the spindle and seat are stainless steel for precise operation, and the valve cone gasket is a special chloroprene (neoprene) compound. The spring housing is closed tightly to avoid refrigerant leakage. After the set pressure is adjusted at Danfoss the valve is sealed, and a metal plate records the flow diameter, set pressure, date of production, production number and type-approved code. Applicable for R717 (ammonia), HFC and HCFC (e.g. R22, R134a, R404A) and R744 (CO2), within a temperature range of -30 to +100 C (-22 to +212 F). The valves are designed for a strength test of 43 bar g (624 psig). It is recommended that the valves be installed in pairs in conjunction with the DSV double stop / change-over valve so one valve can be inspected or replaced while the other keeps the vessel protected. Approved in accordance with the Pressure Equipment Directive (PED) and CE marked; discharge capacity certified to ISO 4126-1 / EN 13136. This code is an SFV 20 (nominal valve size 20 mm (3/4 in), flow diameter 18 mm (0.709 in), flow area 254 mm2 (0.394 in2)) with G outside-pipe-thread connections per ISO 228/1: inlet G 1 1/4 in, outlet G 1 1/2 in. Set pressure 22 bar g (319 psig); de-rated certified coefficient of discharge Kdr 0.54; valve lift 4 mm. PED 2014/68/EU category IV, fluid group I, CE marked. Specifications per Danfoss store code 2416+294.