Boiler Relief Valv Abrz030 3/4 For pressure protection of hot water heating boilers. Iron body with forged bronze inlet, 550,000 BTU/hr. rating. Female inlet and outlet connections. Seat located above drain: water can't be trapped and sediment can't foul seat. Non-mechanical seat-to-di sc alignment will not stick or freeze. Water seal of high temperature resisting material isolates spring working parts from water during relief. Standard Pressure Setting: 30psi (206.9 kPa), Pressure Range: In 5psi (34.5 kPa) increments from 30 to 150psi (2 to 10 bar) with corresponding high ratings at 550,000 BTU/hr.