Pneumatic orbit ball valves has the characteristics of frictionless opening and excellent sealing performance sealing performance operating torque operating torque and high automation. It is widely used in fluid control system of petroleum, gas, chemical industry, power generation, LNG and other industries. Although these valves have a long service life, the routine maintenance of scientific specifications is the key to ensuring stable valve operation in the long run.
Proper maintenance can not only reduce failure rate, but also extend the service life of valves and the pneumatic actuator, while minimizing downtime and maintenance costs. The following is an introduction to routine maintenance of pneumatic orbit ball valves.
1.Check Valve Appearance regularly
During daily inspection, the first step is to observe the overall appearance of the valve for any abnormalities.
Highlights include:
Check the valve body for cracks, corrosion or mechanical damage;
Check flange connection bolts are loose;
Ensure that the the valve nameplate is clear and intact;
Check for peeling or rusting of anticorrosion coating;
Check for media leakage at pipeline connection points.
If visual abnormality is detected, the cause should be analyzed and timely maintenance measures should be taken to prevent the problem from escalating.
2.Check Sealing Performance
Sealing performance directly affects the safe operation of piping system.
In maintenance process, attention should be focused on:
Check valve stem packing for leakage;
Check the flange sealing surfaces for leakages.
When the valve is closed, verify complete closure of the medium;
Check the integrity of valve seat seal.
Frequency of seal inspections should be increased for systems transporting natural gas, flammable/explosive substances or toxic media. Airtightness tests may be conducted if necessary to ensure zero leakage.
3. Maintenance of the Pneumatic Actuator
The pneumatic actuator is the key part of driving track ball valve, and its working condition directly influences the opening and closing performance of valve.
Daily maintenance should include:
Check that the air supply pressure complies with the design specifications;
Make sure air supply is clean and dry without moisture or oil.
Check for leaks in air piping and fittings;
Verify correct operation of solenoid valves, filter regulator and locator;
Observe whether the actuator is moving smoothly and check for abnormal noise or vibration.
Stable and clean air supply effectively reduces wear and tear of internal components of the actuator and improves operational reliability. Open and close volume tests are conducted regularly
If the valve is in a fixed opening or closing position for a long time, the operation performance may be affected by the accumulation or insufficient lubrication of the medium.
It is recommended that, depending on the actual operation, periodic opening and closing tests be conducted to check the following:
Smooth operation on and off;
Normal opening and closing times;
existence of stickiness or tardiness;
Accuracy of feedback of limit switch;
Correct response to automated signals.
Regular business testing can identify potential problems early and prevent business problems caused by prolonged inactivity.
4. Keep valves clean
Industrial environments often contain pollutants such as dust, moisture and oil, and long-term accumulation can affect the normal operation of valves and actuators.
During maintenance process, we should focus on the following aspects of cleaning:
The body surface;
(a) The casing of the implementing body;
Solenoid valves and control accessories;
Gas connection;
nameplates and indicator labels.
For outdoor facilities, also inspect wind and weatherproofing and dust protection measures to prevent rainwater from entering the control system.
5.Check for lubrication and abrasion
Although the crawler ball valve adopts frictionless opening and closing design, some transmission mechanisms still require proper lubrication.
Maintenance inspections should include:
Lubrication status of valve stem transmission components;
Bearing and transmission mechanisms wear;
Seal ring aging;
(a) Harden or wear the packaging material;
Flexibility of fasteners.
Seals and worn parts shall be replaced in a timely manner after reaching the end of their useful life to ensure stable operation of the valve in the long term.
6.Develop a periodic maintenance plan
In order to strengthen equipment management, it is suggested that a perfect maintenance system should be established.
Maintenance plans may include:
Daily visual inspection;
Opening and closing tests questions each month;
Check actuators and control attachments quarterly;
Seal performance is Semi-annual checks;
Annual overhaul and performance testing.
In addition, maintenance records should be established of inspection times, maintenance activities, replacement parts and operational status to provide the basis for equipment management and failure analysis.
Conclusion:
Pneumatic track-type ball valves has the advantages of reliable sealing, low operating torque and high automation, but in order to make full use of its performance capabilities, it is necessary to carry out standardized daily maintenance. By regularly inspecting the exterior, sealing performance, pneumatic actuator, opening andclosing operation, lubrication status, vulnerable parts, etc.,and drawing up a scientific repair plan, the failure rate can be effectively reduced, the service life of the equipment can be extended, and the safety and operating efficiency of industrial piping systems can be improved.
Frequently Asked Questions
Q1.Do pneumatic trunnion-mounted ball valves require to be regular lubrication?
Yes. ' Although trunnion-mounted ball valves has a a friction-free sealing structure, the valve stem, transmission mechanism and some moving parts still require to be periodic lubrication to the manufacturer's specifications to minimize wear and ensure smooth operation.
Q2.How often are pneumatic actuators checked?
It is recommended that the air supply and exterior be inspected in the course of daily inspection, and that electromagnetic valve, filter regulator valve, locator and pneumatic connections be thoroughly inspected quarterly. For applications involving high frequency circulation or critical operating conditions, inspection interval should be shortened accordingly.
