The JF-100RVG is a combination isolation and pressure relief valve. With the ability to customize the valve end connections, relief connections and pressure ratings, the valve is extremely versatile, Jomar adds. Available with factory set points of 80, 100 or 125 psi, and a patent-pending O-ring connection design, every valve includes a 3/8" barb, a 1/2" PEX and a 3/8" compression connection in the box. Jomar Valve.