DescriptionASME Section IV capacity certified bronze safety relief valve for protection of hot water heating boilers, systems, and similar equipment. It can be pre-set to any pressure ranging from 15 to 160 psig (1 to 11 bar) at 250°F (121°C) max. Sizes: 3/4" - 2" (20 - 50mm). ASME Section IV certified capacity. Corrosion resistant construction. Extremely high capacity. Diaphragm isolated spring chamber. Made in the USA.