Maintenance Of Valve Castings

‌Maintenance of valve castings mainly includes the following aspects:

‌Cleaning and lubrication‌: Regularly clean the outer surface and internal parts of the valve to remove impurities such as dust and sand to avoid clogging of the valve or reduced sealing performance due to accumulation of impurities. When cleaning, you can use a detergent and a soft brush to wipe the outer surface of the valve to ensure that there is no dirt residue. For internal parts, it is recommended to disassemble the valve cover and valve body, soak and brush with detergent, and finally rinse with clean water. Lubrication is a key measure to reduce valve wear and extend service life. Regularly apply an appropriate amount of lubricant to the friction surface of the valve to reduce the friction coefficient between moving parts and improve the flexibility of the valve. The choice of lubricant should be matched according to the material of the valve and the use environment to avoid corrosion or damage to the valve by using improper lubricants.

‌Sealing performance inspection‌: Regularly check the sealing surface, sealing gasket and other parts of the valve to ensure that they are free of wear and damage. The valve can be tested for sealing by a leak detection instrument. Once a leak is found, the seal should be replaced immediately. For example, a chemical company found that the gasket of a cast steel gate valve had aged due to long-term use during routine maintenance, resulting in a small amount of medium leakage. After the gasket was replaced in time, the valve restored its normal sealing performance and avoided possible medium leakage accidents.

‌Mechanical parts inspection and adjustment‌: Regularly check the mechanical parts of the valve, including the valve stem, valve stem nut, handwheel and other parts. Check whether the valve stem is bent, deformed or worn, whether the trapezoidal thread of the valve stem nut is intact, and whether the handwheel is loose or damaged. For the bolts on the flange and bracket, ensure that they are complete and the threads are not damaged or loose. If the valve is found to be inflexible or stuck during opening and closing, it should be adjusted in time. For example, a factory found that the valve stem of a cast steel gate valve was stuck due to long-term non-lubrication during routine maintenance. After cleaning and lubrication, the valve resumed normal operation.

‌Protection and storage‌: For valves installed outdoors or in polluted environments, appropriate protective measures should be taken. For example, a protective cover is installed on the valve stem to prevent rain, snow, dust and other dirt from corroding the valve stem. In addition, the integrity of the insulation jacket of the cast steel gate valve should be checked regularly.

Regularly check and replace wearing parts: Regularly check the key parts of the valve, such as the ball, valve stem, sealing ring, etc., to ensure that they are intact. Parts that are severely worn need to be replaced in time. For example, a chemical company found that the sealing gasket of a cast steel gate valve was aging due to long-term use during daily maintenance. After replacing the sealing gasket in time, the valve restored its normal sealing performance.