VALVE FEATURES

A VIP valve (patented by OMAL exclusively) is a proper automaticvalve embodying both interception device (between pipe C-D) and control device (A-B).
It works thanks to the internal movement of a piston supplied with air. At the end of its stroke (a VIP valve is an ON/OFF valve), the piston presses on the seat seal or moves away from it letting the intercepted fluid flow or stopping it from flowing. As the seat is perfectly
tight and the intercepted fluid pressures discharge on it, the pressure necessary to move the piston is completely independent of the fluid pressure. As a result OMAL has been able to design a light space saving and lasting valve. Its full bore and its improved internal dynamics allow minimum pressure losses, too.

CLOSED VALVE

Supplying the hole “A” with air (the hole “B” must be discharging) atthe end of its stroke the piston presses on the seat seal: the valveis closed.
As in Spring Return N.C. executions the spring is in “A”, if there is no control, the piston will touch the seat seal: therefore, the preferable position is the closed one.

TRANSITIONARY PHASE

During the transitionary phase (the picture shows the opening transition in a Double Acting execution), one of the two holes is supplied. The piston moves axially changing the previous closed or open state. In Spring Return N.C. executions, the closing is causedby the spring (if there is no control). In Spring Return N.O. executions, the opening is caused by the spring (if there is no control). Both opening and closing transitionary phases last less than a second.

OPENED VALVE

Supplying the hole “B” with air (the hole “A” must be discharging) atthe end of its stroke the piston is at maximum distance from the seat seal: the valve is open.
As in Spring Return N.O. executions the spring is in “B”, if there is no control, the piston will be away from the seat seal: therefore, the preferable position is the open one.