Description
Initially, flow passes freely from 2 to 1. When the pressure at 1 exceeds the pressure setting, the valve acts to restrict input flow at 2. This increases the pressure drop through the valve and maintains consistent pressure at 1. The spring chamber is drained at 3 to prevent a build-up of back-pressure against the spool. Additionally, if pressure at 1 rises above the pressure setting, flow is relieved to 3 until the setting is re-attained. An undesirable increase in pressure in main port 1 is additionaly prevented by lifting the spring plate off the control spool. Tank pressure is additional to the spring setting.
Note: The valves are not provided with any surface protection.
