1.Screw type for buck-boost, return test are easy to ... high reliability, easy to maintain, no leak, screw type for buck-boost and the pressure is very stable in this ... -off valve, can test the tightness for the gauges calibrated. 4. screw type for buck-boost, and the pressure is ... return test are easy to operate. 5. open type structure for easy cleaning and maintenance. 6. This hydraulic source can ...