SUN Hydraulics 77722558 Balanced Piston Relief Valve Cartridge

The 77722558 is a pilot-operated, balanced piston relief valve cartridge manufactured by SUN Hydraulics (model RPGC-LCN) for Sandvik Mining and Rock Technology (formerly Tamrock) underground drilling equipment. It functions as a main system or circuit pressure limiting device in hydraulic systems. The cartridge fits the standard T-10A (SAE-10) cavity. It features a pressure adjustment range of 70 to 350 bar (1000 to 5000 psi) with a maximum flow capacity of 120 L/min (30 GPM). The valve construction includes a hardened steel poppet and cage for extended service life in contaminated mining environments. Seals are Buna N (Nitrile) standard, compatible with mineral-based hydraulic fluids. The valve is interchangeable with Sandvik OEM part numbers 77722558 and 777 225 58.