... valve. Pressure of pump can be regulated freely. high pressure washer , High pressure cleaning pump unit, portable or stationary, has two ... or frequency-changing. Main parts:Pump body:(material used: HT250)Fluid cylinder body: (material used: 304ss,316ss,316L ss, 2205,630ss ... wear resistant and anti-corrosive after special treatment. high pressure washer, hyper pressure cleaning pump unit