OR valve delivers air at the outlet (A) always supplied by higher pressure (X or Y) - If two signals of different pressure is applied, the higher pressure is connected to outlet (A) -An OR valve (or shuttle valve) is used to allow a function to be executed from either of 2 different places. An output signal is present whenever at least one of 2 signal inputs is activated. It can be used in safety circuits and logic controls. - While ordering OR Valve, mention the ordering number given in the corresponding tables.