3/8 BSP Male X 1/2 BSP Male Couplings. The seller is 23bsolutions and is located in this country GB. PA VB75 unloader valve controlset for a pressure washer pump. Water Flow 30 Litres Per Minute. Pa vb75 unloader valve controlset pressure power washer pump bypass 220 bar 30 l it is the trapped pressure type and will fit a range of interpump pumps and more.