Miaoliu air valveThe installation and maintenance of intelligent air valves in laboratory ventilation systems should follow strict standards. The following are specific points:
1、 Installation specifications
Pre-installation check
Structural inspection: Confirm that the air valve frame is firm, and that the adjustment braking and positioning devices are flexible and reliable. Electric (pneumatic) air valves need to be tested for sensitivity when powered, and residual pressure valves need to be tested for balance.
Applicability confirmation: Check whether the scope of application, installation position, airflow direction, and operating surface of the air valve meet the design requirements. Some brands of air valves are equipped with observation holes to facilitate checking the opening status during later debugging.
Connection inspection: Check whether the reserved flange size, aperture, hole spacing, flange surface flatness, and gasket material of the air duct match. Non metallic air ducts need to confirm that the connection method complies with the specifications.
Installation position and direction
Convenience of operation: The air valve should be installed in a location that is easy to operate, and the manual device of the high-altitude valve should be 1-1.5 meters above the ground or platform.
Airflow direction: Install according to the direction indicated on the air valve housing, and do not install it in reverse. The check valve needs to be installed on the outlet pipe section of the fan, with the opening direction consistent with the airflow, flexible shaft, and tightly closed valve plate.
Space requirements: The effective distance between the air valve operating surface and walls, roofs, or other equipment or pipelines shall not be less than 200mm, and it shall not be installed in structural layers or holes. The width of the seam around the valve should be greater than 150mm.
Support and hanger installation
Independent support and hanger: For single air valves weighing more than 50kg, electric (pneumatic) air valves, constant air volume valves, and soft non-metallic air duct system air valves, independent support and hanger should be installed.
Special requirements for fire dampers: Fire dampers with a diameter or long side size ≥ 630mm must be equipped with independent support hangers and double lifting to prevent parts from jamming and failure due to valve body rotation.
Marking after installation
Mark the direction and degree of opening of "open" and "close" clearly on the outside of the valve body. The insulation system needs to be clearly marked outside the insulation layer for easy debugging and management.
2、 Maintenance points
Daily cleaning
Surface cleaning: Regularly clean the dust, oil stains, and rust on the outer surface of the air valve using a clean soft cloth or brush. For stubborn stains, appropriate cleaning agents can be used (such as mild alkaline cleaning agents for stainless steel valves).
Nameplate protection: Ensure that the nameplate information is clear and readable during cleaning. The nameplate includes key information such as model, specifications, pressure rating, etc.
leak test
External leakage: Check if there is any medium leakage at the sealing part of the valve stem and the flange connection. You can apply leak detection liquid (such as soapy water) around the valve stem and observe the formation of bubbles.
Internal leakage: Depending on the valve type and working medium, internal leakage can be determined by observing downstream pressure changes after closing the valve or using gas detection instruments.
Operational performance check
Manual valve: Regularly operate the valve, check whether the opening/closing is flexible, whether the operating force is uniform, and whether there is any jamming or abnormal resistance.
Electric valve: Check whether the power connection and wires are damaged, whether the control signal transmission is normal, whether the operating speed meets the requirements, and whether there is any abnormal vibration or noise.
Lubrication and maintenance
Lubrication point inspection: Determine the lubrication points of valve stem, bearings, gears, etc., and check whether the lubricant is sufficient.
Lubricant selection: Choose the appropriate lubricant according to the working environment (such as lithium based grease for normal temperature environment and fluorine based grease for chemical corrosion environment).
Lubrication operation: Lubricate according to the correct method and cycle, avoiding excessive injection. After lubrication is completed, operate the valve several times to evenly distribute the lubricant.
attachment check
Filter: Regularly check whether the upstream filter is clogged, judge by pressure difference, and clean or replace the filter element in a timely manner.
Pressure gauge and safety valve: Check whether the pressure gauge pointer accurately indicates the pressure, whether the opening pressure of the safety valve meets the requirements, and whether the sealing performance is good.
Professional maintenance (grease injection maintenance)
Fat injection amount and pressure: Accurately calculate the grease injection amount based on the valve type and sealing capacity. The grease injection pressure should be moderate to avoid excessive or insufficient pressure affecting the effect.
Inspection of grease injection effect: Open or close the valve to check the lubrication effect and confirm that the surface of the valve ball or gate is evenly lubricated.
Discharge and pressure relief: Discharge and pressure relief should be carried out before grease injection to ensure smooth operation. Seal the grease injection port after injection to prevent impurities from entering.