General • Inspections

Checklist for Valve Inspection

Use this procedure to check for your valves. Note that steam valves are especially important to check regularly. They can be more prone to stem failure from internal steam pressure or condensation when open, resulting in worn plugs or seals or even broken plugs or stems.

MaintainX

09/16/2022

Checklist for Valve Inspection

The following steps are recommended as part of an effective valve inspection program:

Valve Checklist:

Test for control loop stability by monitoring the control temperatures and valve positions over time either at the plant room or from the higher level BMS to which the devices are connected.
Create a trend graph with valve/damper actuator positions, available temperature (supply, discharge, and space) and observe that the heating and cooling systems are functioning as designed during normal operation. If irregularity is observed, such as hunting or temperature response, then tune the control loop accordingly.
Visually check the valve for leakage.
Close the drive valve and allow time for the downstream temperature to stabilize. Then check with a temperature probe to establish the valve is shutting off. If there is evidence of let-by then investigate further. (See Appendix for more information)
Check for valve stem showing signs of weeping around the gland. If present, replace gland kit or entire valve.
Look for signs of galvanic corrosion on valve body and pipe work. This can lead to leaking and requires wire brushing and anti-corrosive paint applied or the connection remade in severe cases.
Check valve bonnet for evidence of scoring, likely caused by faulty actuator mounting; tighten accordingly.
Check for rattling sounds (preferably use acoustic listening device) which can indicate the plug becoming detached from the stem. If necessary, replace stem and plug assembly or entire valve.

Note that steam valves are especially important to check regularly. They can be more prone to stem failure from internal steam pressure or condensation when open, often resulting in worn plugs or seals or even broken plugs or stems. Special precautions and additional care should be taken when inspecting/working with steam control valves.

Source: MaintainX (Community Member)

The following steps are recommended as part of an effective valve inspection program:

Valve Checklist:

Test for control loop stability by monitoring the control temperatures and valve positions over time either at the plant room or from the higher level BMS to which the devices are connected.

Visually check the valve for leakage.

Close the drive valve and allow time for the downstream temperature to stabilize. Then check with a temperature probe to establish the valve is shutting off. If there is evidence of let-by then investigate further. (See Appendix for more information)

Check for valve stem showing signs of weeping around the gland. If present, replace gland kit or entire valve.

Look for signs of galvanic corrosion on valve body and pipe work. This can lead to leaking and requires wire brushing and anti-corrosive paint applied or the connection remade in severe cases.

Check valve bonnet for evidence of scoring, likely caused by faulty actuator mounting; tighten accordingly.

Check for rattling sounds (preferably use acoustic listening device) which can indicate the plug becoming detached from the stem. If necessary, replace stem and plug assembly or entire valve.