This 1/2 inch dial set high capacity feed water pressure regulator is for use in commercial and residential hydronic heating systems to fill the boiler and piping system with water, and to maintain water pressure in the system at all times. It also provides make-up water to the system in the event of system leaks. It consists of an easy-to-read dial pressure setting indicator, bronze body with union threaded inlet and NPT threaded outlet connections, tight seating check valve, fast-fill purge lever for manual purging, and a stainless steel strainer. It has high capacity performance and a simplified servicing design. It is suitable for use in the boiler feed lines of hydronic heating systems. The maximum pressure is 100 psi