The soft start valve is needed to prevent harming people or equipment when pressurising a pneumatic system. The specification of this component allows the gradual pressurisation of a pneumatic system. Pressure is gradually increased until 50% of the system pressure is reached. System pressure then increases to 100% of the set pressure in a very short time.

The natural location of the slow start valve is after the F.R.L.; in fact, the flanging allows for perfect adaptability with G1 Series C. Two different types of slow start valves are available: with electrical or pneumatic operation. For electrically operated soft start valves, a 3-way normally closed solenoid valve model A631- AC2- is used. This valve starts only when the electrical switch is operated. For pneumatically operated soft start valves, the base A631-AC2- AVP/-P incorporating a Super Rapid fitting ø4 is used. This Super Rapid fitting receives the signal produced by a NC 3-way manually oper-ated valve which acts as a general switch.