General Discrption

Changeover , also called selector valve, is a three way device usually for changing the direction of the flow in pipelines. It also can be put in the situation of two safety valves and a pressurized system as a pressure relief system where the changeover valve ensures that we always have one standby valve ready for emergency. The condition also permits regular maintenance can be carried out without interrupting the work of the whole device.

The simple design from Dervos allows easy assembly, dis-assemble and easy maintenance. The valve also can handle various applications--high temperatures, cryogenic service, dangerous fluids and many others.

Design Features

Full Bore: The full-bore channel brings superior transporting performance. This valve is also designed to minimize the pressure drop and flow-resistance.

Zero Leakage: With emission-free packing and the static sealing part of the body, which is double-sealed by oval-ring and metal jacketed graphite gasket, the valve meets the demands of corresponding working conditions.

Long service life: The valve enjoys easy maintenance and long service life, which benefits from the plane sealed sealing face of the valve and the alloy welding technology.

Quick Detail

Technical Drawing

Dervos Quality Checking System

In Dervos, we control quality throughout the whole manufacturing process.

Casting inspection:

We can find out the problem of raw material, such as shoddy casting, unqualified wall thickness, chemical composition and so on, which ensure that you will not be cheated.  

Machining Inspection:

On the one hand, we could ensure machining accuracy through this process. On the other hand, we could find out machining mistake as early as possible, to win more time for repairing and remaking

Final Inspection:

Final inspection activities include document and QC record review, visual examination, dimension check, pressure test, painting and packing check. You don’t need to come and inspect in person and all the documents could be provided as proof.