Lead-free design is suitable for all no-lead potable water installations, in full compliance of all lead-free plumbing laws. Available with two factory pre-set water pressure relief pressures, to accommodate residential and commercial well applications: 75 p.s.i. and 100 p.s.i. Designed and calibrated for water well pressure relief, to prevent system damage. Adjustable relief pressures, from 75 or 100 p.s.i., to 150 p.s.i. Heavy-duty stainless steel coil-spring design ensures positive closure.