Brief Introduction to Cock Valves for Glass Plate Level Gauges

1. Connect & cut off the medium channel When fully opened, they link the container and glass plate gauge to form a communicating vessel, so operators can directly observe liquid level height through the sight glass. When closed, they completely isolate the level gauge from the tank.
2. Safe maintenance & replacement Before cleaning, repairing or replacing the broken glass plate, close both upper and lower cocks to cut off medium circulation. No need to shut down the whole equipment, which greatly simplifies maintenance workAlibaba.co....
3. Emergency self-sealing protection Most cocks are equipped with built-in anti-leak steel balls. If the glass plate bursts accidentally, medium pressure will push the ball to block the passage instantly, avoiding massive leakage of high-temperature, high-pressure or hazardous fluid and ensuring site safety.
4. Drainage & venting operation The small side branch port on the cock can discharge residual liquid inside the level gauge, or exhaust trapped air to eliminate air bubbles that interfere with level reading.

Maintenance Methods for Cock Valves of Glass Plate Level Gauges

1. Daily Inspection

   Regularly check the sight glass level gauge valves for boilers for liquid or gas leakage at the sealing surfaces, thread joints and discharge nozzles. Confirm the handle rotates smoothly without jamming or abnormal resistance. Check whether the built-in self-sealing ball inside each cock is intact.

2. Regular Lubrication

   Every 1–3 months, add high-temperature resistant lubricant to the rotating plug of the cock. Avoid excessive grease to prevent contamination of the measured medium. After lubrication, turn the handle back and forth several times to spread lubricant evenly.

3. Cleaning Treatment

   Shut off both upper and lower cocks first, then drain residual medium through the drain port. Remove sediment, scale and impurities attached to the plug and valve cavity. Hard scale can be cleaned with a neutral descaling agent; rinse thoroughly with clean medium afterward.

4. Sealing Performance Maintenance

   If leakage occurs when the cock is fully closed, replace the PTFE sealing gasket inside the valve. Check the conical matching surface of the plug for scratches or corrosion. Grind slightly if minor abrasion exists; replace the whole cock if there is severe damage.

5. Self-sealing Ball Inspection

   Disassemble periodically to inspect the anti-spill steel ball. Ensure the ball moves freely without jamming. Replace deformed, rusted or stuck balls immediately, as they are critical for emergency leakage prevention when the glass plate breaks.

6. Periodic Functional Test

   Carry out opening and closing tests on the cocks regularly. Verify that the valve can completely cut off the flow without seepage. Test the vent and drain ports to guarantee smooth exhaust and drainage.

7. Long-term Shutdown Protection

   If the equipment stops running for a long time, drain all media inside the cocks completely, clean the inner cavity, apply anti-rust oil on metal parts, and close the valve slightly (not fully tight) to protect the sealing surface from permanent compression deformation.

8. Replacement Standard

   Replace the sight glass level gauge valves for boilers for boilers directly when there is severe corrosion, deep scratches on the plug sealing surface, or irreparable leakage after gasket replacement.