This two valve system has been designed to prevent risks in case of failure of High Pressure Preheaters.

It consists of one 3 way valve and one 2 way valve having both an internal piston connected to the stem and sliding into a cylindrical chamber.

In case of heater tube bundle failure, a level switch sensing the water level in the Preheater shell will open the exhaust valves generating differential pressure between the two parts of the cylindrical chamber.

This pressure difference actuates the stem movement, operating the valves and deviating the flow, therefore bypassing the Preheater.

Operating speed can be controlled by an external regulating valve. All this system does not need any external power (i.e. electric or pneumatic) so giving best protection in case of accident.

We produce this system according to rating ASME 900, 1500, 2500 and Special Classes in size up to DN 18".

Click on the link below
to see how the system works