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  • Mirab Co.

Double Flanged Butterfly Valve with By-Pass

Size (mm) : 500-1400
Pressure rating : 6-40 (bar)
Body Material: All Types of Ductile Cast Iron, Cast Steel, Stainless Steel, Copper Alloys
Disc Material: All Types of Ductile Cast Iron, Cast Steel, Stainless Steel, Copper Alloys

This valve is equipped with a bypass system and an on/off valve. Bypass system is used for connecting both side of the disk for special applications. The usual diameter of bypass valve is approximately 1/10 of nominal diameter of the main valve. For installation of bypass the face to face of the main valve is increased.

Paint Coating :
Electrostatic epoxy powder (RAL 5005 or 5015) with min. thickness 250 micron.

Application:
This system (bypass) is used for making equal pressure in both side of the disc so the main valve can be operated with minimum force for opening and closing. This system can be used for filling up piping systems. As long as the pipeline system is protected from water Hammer phenomenon and the pipeline will fill up gradually and at the same time air will be ejected from pipeline (through air valves) without any disturbance and minimum sound.

Operation:
Opening the valve: to start operation when the main valve and bypass valve are in closed position first open the bypass valve, and after opening the by pass valve the main valve will be opened. For transferring the liquid during operation time, both valves (main and bypass) should be open. Closing the valve: When system is not in use or the system has to be shut down, first main valve should be closed and then by pass valve will be closed.If the above procedure takes place, difficulties with air and water hammer will be reduced enormously.