Slave Exhaust Valve

The exhaust valve operates when the pilot exhaust valve is opened, allowing air to be exhausted quickly.

The slave exhaust valve also provides the system pressure relief function which protects the air suspension system from over inflation. The valve is pneumatically operated, responding to air pressure applied to it to overcome force from its internal spring. The valve is connected into the main pressure gallery which is always subject to the system pressure available in either the air springs or the reservoir. The valve is controlled by a spring which restricts the maximum operating pressure to the specified limit.

The minimum pressure in the system is also controlled by the slave exhaust valve to ensure that, even when deflated, the air springs contain a positive pressure with respect to atmosphere. This protects the air spring by ensuring it can still 'roll' over the piston without creasing.