Installation of welded ball valve

• Welded ball valves can be installed in any position with any direction of the working medium flow.
• Before installation, the plugs from the valve nozzles should be removed, and its operability should be checked by turning the handle, visually verifying the rotation of the ball. The handle axis must be parallel to the axis of the passage opening in the ball.
• If the welded valve is installed on a horizontal pipeline, the ball should be fully open during installation.
• If the installation is carried out on a vertical section, during the welding of the upper nozzle, the ball should be fully open to avoid damage by slag, and during the welding of the lower nozzle, the ball should be closed to avoid overheating from the welding heat.
• The welding of the ball valve should be done by electric welding. Gas welding is allowed for valves with a nominal diameter of less than 150 mm.
• During welding, it is necessary to avoid overheating of the end seals of the ball. The maximum permissible temperature on the surface of the valve body is 80°C. If the temperature rises above 80°C, the valve body should be cooled with a wet rag.
• It is not allowed to turn the valve handle immediately after welding without waiting for it to cool.
• Cutting of welded nozzles is not allowed since their length corresponds to the minimum length at which the welding does not overheat the end seals of the ball.
• The valve should not withstand loads from attached pipelines (bending, compression, tension, twisting, displacement, vibration). If necessary, supports or compensators should be provided that remove the load from the valve body. It is not allowed to install welded valves on pipelines that are subject to vibration.
• The valve should not be used as a support for the pipeline.
• Ball valves with electric and pneumatic actuators should be installed with the stem pointing vertically upwards. If installed outdoors above an electric actuator, a protective pavilion should be arranged.
• When installing large-diameter ball valves using lifting equipment, suspension should be made through the factory mounting holes in the body. It is forbidden to use a flywheel, reducer, or electric drive for suspension.
• During underground trenchless installation, a compacted sand bed with a thickness of at least 200 mm should be arranged under the ball valve, made of material with a particle size not exceeding 10 mm without sharp corners.
• After installation, hydraulic testing of the section must be carried out. The test pressure during pressurization should not exceed the test pressure established for each of the tested elements. During hydraulic testing, all ball valves, except for drain and compartment ones, must be in the fully open position.
• If solid impurities can appear in the working medium at the installation location of the ball valve, a mesh filter must be installed before the valve. Otherwise, abrasive wear of the ball may lead to a violation of the sealing of the closure.

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