As the weather gets colder and the temperature drops - especially in areas with large diurnal temperature fluctuations or below freezing - maintenance of electric valves becomes crucial. The core principle is to prevent freezing, moisture, condensation, and ensure that the mechanism remains flexible and reliable to avoid problems such as valve jamming, seal damage, or electrical component failures caused by low temperatures.

The following are detailed maintenance steps and key points, which can be adjusted according to the installation environment (indoor/outdoor) of the valve and the type of medium being processed (whether it is easy to freeze):

I. Mechanical component maintenance (valve body, actuator)
Insulation and heat tracing (the most critical measures)

For valves conveying water or media that may solidify: if the valve is installed outdoors or in unheated space, heat insulation materials (such as mineral wool, glass fiber, polyurethane foam shell) must be installed on the valve body and connected pipes.

For cold regions: Install heat tracing cables inside the insulation layer. The heating belt provides continuous heat to prevent the medium from freezing, thereby avoiding the risk of valve plug freezing or valve body cracking due to expansion.

Checkpoint: Regularly check the integrity of the insulation layer to ensure proper heat tracing function.

Drainage and antifreeze

When the system is shut down or undergoing maintenance, be sure to drain all water or residual media from the valves and pipelines, especially for valves that have not been used for a long time. Open the drain plug or valve and completely remove any remaining liquid.

For pneumatic actuators (if your electric valve uses an electric pneumatic converter), please ensure that the air line filter and dryer are working properly. Regularly drain the condensate from the gas storage tank and dehydrator to prevent it from freezing in the pipeline.

lubrication

Low temperature can cause the lubricating grease to thicken or even solidify, making valve operation difficult.

Before winter arrives, check and replace lubricants suitable for low-temperature environments (such as low-temperature lithium based grease). Lubricate moving parts such as valve stems and bearings. Be careful not to lubricate excessively to avoid attracting dust.

Sealing inspection

Low temperature can cause certain rubber sealing materials (such as NBR) to harden, become brittle, and lose elasticity, leading to leakage.

Check for signs of leakage in the sealing areas such as valve stem packing and flange gasket. If the valve is in critical use, consider replacing the seals with low-temperature resistant materials such as fluorocarbon rubber (FKM/fluororubber) or polytetrafluoroethylene (PTFE).

2、 Maintenance of electrical components (electric actuators, positioners, limit switches)

Moisture and condensation prevention

The temperature difference between day and night can cause condensation inside electrical enclosures, leading to short circuits and component corrosion.

Installation of heater: A small wattage anti condensation heater can be installed in the control cabinet of the electric actuator. It will automatically start at low temperatures to keep the interior dry.

Check the seals: Ensure that the gaskets and seals of the electrical enclosure are intact and tighten the cover bolts to prevent moisture and water from entering.

Use desiccant: Place the silicone desiccant bag inside the casing and replace it regularly.

Connection check

Check if all power, signal, and control wiring is securely fastened. Look for loose terminals, as thermal shrinkage can cause loose connections.

Check the waterproof integrity of the cable sealing sleeve entrance.

Mechanical operation test

As the weather begins to cool down, regularly perform full open and full closed cycle tests on the valve. This helps:

Identify sticking issues caused by low temperatures.

Evenly distribute lubricant.

Prevent the mechanism from getting stuck in one position due to prolonged inactivity.

Important reminder: If the medium freezes, do not attempt to operate the electric actuator as this may burn out the motor or damage the gearbox.

III、 Daily maintenance and management
Increase inspection frequency

Increase the frequency of winter inspections, with a focus on:

Any abnormal leakage (from valve body, valve stem).

Whether the insulation and heat tracing are working properly.

Any abnormal noise or hesitation during the operation process.

Condensation or water ingress inside the electrical enclosure.

Maintenance and upkeep records

Record each maintenance activity - date, tasks performed, and issues discovered. This helps with status tracking and facilitates planning for preventive maintenance.

Summary: Winter Maintenance Checklist for Electric Valves
Maintenance category specific task indoor valve outdoor valve (no freezing risk) outdoor valve (freezing risk)
Mechanical component emission medium ★★★★★★★★★★★ (basic)
Install insulation layer ★★☆★★★★★★★★★ (basic)
Install heat tracing ☆☆☆★★★★★★★★★ (basic)
Use low-temperature grease ★★★★★★★★★★★
Check/replace low-temperature sealing components ★★☆★★★★★★★
Electrical component inspection shell seal ★★★★★★★★★★
Install anti condensation heater ★☆☆★★★★★★★★
Check the tightness of the connection ★★★★★★★★★★★
Regular operation and management testing ★★★★★★★★★★
Increase inspection frequency ★★☆★★★★★★★★
★ Symbol Guide: ☆ (optional/depending on specific situation) ★ (recommended) ★★ (recommended) ★★★ (important) ★★★★ (crucial)