four poppet valves are mounted in a common machined body which has a single inlet port , a pair of working ports and a pair of exhaust ports . the body interior has four valve ports , two of which connect the inlet port to the two working ports and the other two connecting the working ports with the exhaust ports . the housing also has identically sized guide supports and piston chambers for the poppet valves . these may be chosen either as normally closed or normally open straight way valves in a variety of arrangements . with each arrangement one or more pilot valves , either straight way , three - way or four - way , normally closed or normally open , may be connected to the piston chambers . thus , the valve system may be arranged to have a four - way function as controlled by a single normally closed three - way pilot valve , operate two independent fluid motors using two three - way pilots , or can be arranged for various other control functions .