Installation of welded ball valve

• Welded ball valves can be installed in any position with any direction of flow of the working medium.
• Before installation, remove the plugs from the valve ends and check its operability by turning the handle, visually confirming the rotation of the ball. The axis of the handle should be parallel to the axis of the passage hole in the ball.
• If a welded valve is installed on a horizontal pipeline, the ball should be fully open during installation.
• If installation is carried out on a vertical section, during the welding of the upper pipe, the ball should be fully open to avoid damage from slag, and during the welding of the lower pipe, the ball should be closed to avoid overheating from the welding heat.
• The welding of the ball valve should be performed using electric welding. Gas welding is allowed for valves with a nominal diameter of less than 150 mm.
• During welding, avoid overheating the end seals of the ball. The maximum allowable temperature on the surface of the valve body is 80°C. If the temperature exceeds 80°C, the valve body should be cooled with a wet cloth.
• Do not turn the valve handle immediately after welding, wait until it cools down.
• Cutting the welded pipe ends is not allowed, as their length corresponds to the minimum length that ensures the welding does not overheat the end seals of the ball.
• The valve should not bear the loads of connected pipelines (bending, compression, stretching, twisting, displacement, vibration). If necessary, supports or compensators should be provided to relieve the loads from the valve body. It is not allowed to install welded valves on pipelines that are subjected 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 vertically upwards. In the case of outdoor installation, a protective pavilion should be equipped over the electric actuator.
• When installing large-diameter ball valves with hoists, suspension should be carried out through the factory mounting holes in the body. It is prohibited to use the handwheel, gearbox, or electric actuator for suspension.
• For underground installation without a trench, a compacted layer of at least 200 mm thickness, made of material with a particle size of no more than 10 mm without sharp edges, should be arranged under the ball valve.
• After installation, hydraulic testing of the section must be carried out. The test pressure during the pressurization should not exceed the test pressure established for each of the tested elements. During hydraulic testing, all ball valves, except for the release and cut-off elements, should be fully open.
• If solid impurities in the working medium may appear at the installation site of the ball valve, a mesh filter should be installed before the valve. Otherwise, abrasive wear on the ball may compromise the tightness of the closure.

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