The R312H Series first-stage regulators are designed for use as the first stage portion of a two-stage regulation system on domestic applications. With an overall length of only 4.13-inches (105 mm), they fit easily under the tank dome.

The unit is nonadjustable and virtually tamper proof. Outlet pressure remains at the factory nominal setting of 10 psig (0,69 bar). These units contain a relief valve and a large vent. The spring case is color-coded red to easily identify the unit as a first stage regulator.

The R522H Series first-stage regulators are designed for use as the first portion of a two-stage regulation system on domestic applications. This unit features the latest design in regulator technology and is constructed using corrosion-resistant and wear-resistant materials.

A large 3/4-inch FNPT drip lip vent reduces the chance of blockage by freezing rain or sleet when properly installed with the vent pointing down. The overall 6.13-inch (156 mm) profile makes the R522H Series ideal for under the dome installations.