Double Block & Bleed Ball Valve

The installation procedure for ball valves is critical to ensuring both long life and satisfying performance. Valves stored on site awaiting installation should be kept in their original packing, in dry conditions, where damage cannot occur.

Before carrying out the installation, it is important to follow the basic procedures described below:

Carefully unpack the valve and check valve nameplate for identification of materials.

Remove all packing materials.

All valves are bi-directional and supplied ready to use. Valves can be placed with stem oriented to any direction.

Check the valve for any flow direction indication marks. Appropriate care must be taken, to install the valve for proper flow orientation.

Inspect the valve interior through the end ports to determine it is clean and free from foreign matter according to ASME G93-03E1.

Ensure that all auxiliary connections, if any, (lubricators, drains, vents) are free of damage and properly tightened.

Cycle the valve and inspect any functionally significant features.

Read all the literature and note any special warning tags or plates attached to the valve.

Before installation check to insure the ball is in the fully open position in order to prevent possible damage to the ball and seats. The valve performance depends on its original

Welding of valves shall be performed by a qualified person according to the ASME Boiler Construction Code Section IX. For valves to be welded within the E.U., refer to the requirements of ESR 3.1.2 of the Pressure Equipment Directive 97/23/EC.

Valves that will be welded directly to the line must be in the fully open position to protect the ball and seats from excessive temperatures during the welding procedures.

Protect or remove actuators from weld splatter or arc strikes. Valves in the “Fail Close” position should be cycled to the open position.

Allow free flow of water through the drain bottom valve and overflow through the vent valve to prevent overheating all through the welding process. DO NOT heat the center section over 150° C.

Align valve to pipe line, ensuring proper fit to minimize pipe load. Tack weld only.

Complete welding in small segments. Allow enough time for cooling between each segment.

Do not rotate the valve before flushing the line.

Valves with flanged ends should be treated as a single unit and should not be dismantled when installing to pipeline.

Before installing the valves, make sure that the flanges on the mating pipe are free from excessive grit, dirt or burrs, and that there is no mechanical damage to the flanges on the pipe.

When inserting the flange bolts, make sure the bolts are correct size to hold pressure and axial forces.