Valve installation precautions

The quality of the valve installation directly affects the use, so careful attention must be paid.

1, direction and location

Many valves have directionality, such as shut-off globe valves, throttle valves, pressure reducing valves, check valves, etc., if installed reversed, it will affect the effect and life (such as throttle), or not at all (such as Pressure reducing valve), even causing danger (such as check valves). Generally, the valve has a direction mark on the valve body; if it is not, it should be correctly identified according to the working principle of the valve.

The valve installation position must be convenient for operation. It is best to match the valve handwheel with the chest. The floor valve handle wheel should be facing up, do not tilt. The valve against the wall machine should also leave room for the operator to stand. It is necessary to avoid the operation of the sky, especially acid and alkali, toxic media, etc., otherwise it is very unsafe. Do not flip the gate (ie, the handwheel is down), otherwise the medium will remain in the bonnet space for a long time and it will easily corrode the valve stem. Open the gate valve, do not install it in the ground, otherwise the exposed valve stem will be corroded due to moisture. Lifting check valve, the valve flap should be vertical when installing, so that the lifting is flexible. Swing check valve, to ensure the level of the pin when installing. The pressure relief valve should be installed upright on a horizontal pipe and not tilted in all directions.

Cast Steel Ball Valve

2, construction work

Care must be taken during installation and construction. Do not hit the valve made of brittle material. Before installation, the valve should be inspected, check the specifications and models for damage, especially for the valve stem. Also turn a few times to see if it is skewed, because it is most likely to hit the valve stem during transportation. Also remove debris from the valve. When the valve is lifted, the rope should not be attached to the handwheel or the valve stem to avoid damage to these parts and should be attached to the flange.

Always clean the piping connected to the valve. When installing a flange type butterfly valve, pay attention to tightening the bolt symmetrically and evenly. The valve flange and the pipe flange must be parallel and the clearance is reasonable to avoid excessive pressure or even cracking of the valve. Pay particular attention to brittle materials and valves that are not strong enough. The valve to be welded to the pipe shall be spot welded first, then the closing member shall be fully opened and then welded.

  1. Protection measures

Some valves must also have external protection, which is insulation and cold preservation. Hot steam lines are sometimes added to the insulation layer. What kind of valve should be kept warm or cold, according to production requirements.

In principle, if the medium in the valve reduces the temperature too much, it will affect the production efficiency or freeze the valve, so it needs to be insulated or even mixed with heat; if the ball valve is exposed, it is unfavorable to production or cause frosting and other undesirable phenomena, it needs to keep cold.

4, bypass and instrumentation

Some valves, in addition to the necessary protection facilities, also have bypass and instrumentation. A bypass is installed. Easy to repair the trap. Other valves are also installed with bypass. Whether to install the bypass depends on the condition of the valve, the importance and the requirements of the production.