By Ian Duncan
When selecting the correct valve for an application, two main criteria must be considered: pressure and flow. Recently, there has been a movement within industry to run machines with increased system pressure. The push to use smaller and lighter weight components has forced pressures to rise above the formerly standard 3000 psi range in order to achieve a similar system performance. When higher pressures are used, valves must be chosen to handle it, along with all the other parts in the system. It is not uncommon to be in the 4000-5000 psi range, or even higher, on today’s mobile equipment. This pressure must be considered in a valve design. The second important piece of information is flow. Valves must be sized for the correct flow passing through them. Flow forces could actually cause a valve to shift unintentionally. Valves will malfunction if pressure and flow are inadvertently overlooked.