The GM series of mini liquid pumps are single acting, single 80mm air drive units that are capable of pressures in excess of 11,000 PSI / 800 BAR. The Gretec Pump model number reflects the pumps nominal pressure ratio , while the technical data indicates exact ratios. The outlet stall pressure is easy to set by adjusting the air drive pressure and by simply multiplying the pressure ratio by the air drive pressure, the nominal liquid pressure can be calculated.