Danfoss SFA 15 angle-way safety relief valve, code 148F3321, set pressure 21 bar (305 psig), supplied with a TUV pressure-setting certificate. The SFA 15 is a standard, direct-loaded, back-pressure-dependent safety relief valve specially designed to protect pressure vessels and other refrigeration components against excessive pressure. The spring housing is closed tightly to avoid refrigerant leakage. On a rise in pressure above the set pressure the valve initially starts to open slightly; it is fully open before the pressure is 10% above the set pressure and fully closed before the pressure is 10% below the set pressure. Inlet connection 15 mm (G 1/2 in) outside pipe thread to ISO 228/1, outlet 20 mm (3/4 in); inlet flow diameter (do) 13 mm (0.512 in), flow area (A0) 133 mm2 (0.206 in2), de-rated certified discharge coefficient (Kdr) 0.73, effective discharge area 97 mm2 (0.150 in2). Housing is special steel approved for low-temperature operation; spindle, cone and seat are stainless steel, and the cone gasket is a special chloroprene (neoprene) compound. Applicable for the refrigerants HCFC, HFC, R717 (ammonia) and R744 (CO2) within a temperature range of -50 to 100 C (-58 to 212 F); below -30 C full tightness is only guaranteed when the refrigerant pressure is equal to or lower than 0.5 x set pressure. The set pressure is adjusted and sealed at the Danfoss factory. PED 2014/68/EU conformity assessment category IV, fluid group I, 13 mm nominal bore. Specifications per Danfoss store code 148F3321.