a priority control valve for the priority steering control and the auxiliary circuits of the hydraulic system of a fork lift truck or the like characterized in that the housing interchangeably accommodates different priority flow control spools according to the type of steering control valve which is used i . e . a closed center steering control valve with a variable meter - in orifice in the pressure feed circuit or a closed center steering control valve with a variable meter - out orifice in the steering cylinder return circuit or an open center steering control valve with an orifice in the priority flow divider spool to determine the priority circuit flow by controlling a variable displacement pump when the priority circuit itself is operated or when the priority circuit load pressure is greater than the load pressure of the auxiliary circuit .