What is the function and principle of diaphragm valve? What should I do if the diaphragm valve malfunctions?
Qinhuangdao Victor undertakes diaphragm valve maintenance services. Qinhuangdao Victor has a "maintenance and inspection department" that can timely encounter and quickly solve various problems that arise during equipment use through maintenance services. Reduce the failure rate of equipment, improve the efficiency of equipment use, and make it more convenient, worry free, economical, and reassuring for customers to operate the equipment.
Introduction to diaphragm valve
The structural form of diaphragm valve is very different from that of general valves. It is a new type of valve and a special form of shut-off valve. Its opening and closing member is a diaphragm made of soft material, which separates the valve body cavity from the valve cover cavity and driving components. It is now widely used in various fields. The commonly used diaphragm valves include rubber lined diaphragm valves, fluorine lined diaphragm valves, unlined diaphragm valves, and plastic diaphragm valves.
1、 The function of diaphragm valve
The diaphragm valve connects the low-pressure oil system of the lubricating oil with the high-pressure oil system of the EH oil. Its function is to block the turbine through the EH oil system when the low-pressure oil pressure of the lubricating oil system drops to 1.4 MPa. When the steam turbine is working normally, the turbine oil from the lubrication system enters the oil chamber on the piston inside the valve, overcomes the spring force, and places the valve in the closed position, blocking the oil discharge channel of the EH emergency shut-off oil main pipe, and putting the EH system into operation. When the emergency governor is activated or manually tripped, it can cause the turbine oil pressure to decrease or disappear, thereby opening the compression spring to release the EH emergency governor oil and closing all inlet valves.
The advantage of diaphragm valve is that its operating mechanism is separated from the medium passage, which not only ensures the purity of the working medium, but also prevents the possibility of the medium in the pipeline impacting the working parts of the operating mechanism. In addition, there is no need to use any form of separate seal at the valve stem unless it is used as an safety facility in controlling hazardous media.
2、 Working principle of diaphragm valve
Diaphragm valve is a special form of shut-off valve, whose opening and closing component is a diaphragm made of soft material, which separates the valve body cavity from the valve cover cavity and driving components. Diaphragm valve is an elastic and flexible diaphragm connected to a compression element by bolts. The compression element is operated by the valve stem to move up and down. When the compression element rises, the diaphragm is raised, creating a passage. When the compression element descends, the diaphragm is pressed against the valve body weir (if it is a weir valve) or the bottom of the contour (if it is a straight through valve). Diaphragm valve is suitable for switching and throttling purposes.
The reason for the structural design of the diaphragm valve itself is particularly suitable for ultra pure media or heavily polluted, highly viscous liquids, gases, corrosive or inert media. When combined with control equipment, diaphragm valves can better replace other traditional control systems, especially suitable for solid and easily contaminated inert media.
Mainly used in biopharmaceuticals, food, and industries; In the industrial water treatment of industries such as power, chemical, electroplating, etc., diaphragm valves are also used in the production of semiconductor wafers. Diaphragm valves are particularly suitable for transporting corrosive and viscous fluids, such as mud, food, drugs, textile adhesives, etc. Because the operating mechanism of diaphragm valves in pipelines is not exposed to the transport fluid, they are non polluting and do not require packing. The valve stem packing part is also unlikely to leak.
The working temperature of diaphragm valves is usually limited by the materials used for the diaphragm and valve body lining, and its working temperature range is approximately -50 to 175 ℃.
3、 Maintenance of diaphragm valve
① Before installing the diaphragm valve, carefully check whether the operating conditions of the pipeline are consistent with the specified range of use of this valve, and clean the inner cavity to prevent dirt from blocking or damaging the sealing components.
② Do not apply grease on the rubber lining layer and rubber diaphragm surface to prevent rubber swelling and affect the service life of the diaphragm valve.
③ Handwheels or transmission mechanisms are not allowed for lifting purposes and collisions are strictly prohibited.
④ When manually operating the diaphragm valve, auxiliary levers should not be used to prevent excessive torque from damaging the driving components or sealing parts.
⑤ Diaphragm valves should be stored in a dry and ventilated room, and stacking is strictly prohibited. The channels at both ends of inventory diaphragm valves must be sealed, and the opening and closing components should be in a slightly open state.
4、 Solutions to Common Malfunctions of Diaphragm Valves
Common faults of diaphragm valve 1: diaphragm damage
① Cause: Aging of rubber and fluoroplastic diaphragms
Prevention and elimination methods: Regular replacement.
② Cause: Excessive operating pressure, damaging the diaphragm
Prevention and elimination methods: The operating force should be small, and attention should be paid to closing the mark.
③ Cause: Foreign objects embedded between the diaphragm and valve seat, compressing or wearing the diaphragm
Prevention and elimination methods: Do not force the valve to close during operation. It should be opened and closed repeatedly up and down several times, and after washing away foreign objects, the valve should be officially closed tightly; Replace the diaphragm promptly after it is damaged.
④ Cause: The opening height is too high, causing the diaphragm to break
Prevention and elimination methods: It is not advisable to open it too high during operation.
Common faults of diaphragm valve 2: operational failure
① Cause: Diaphragm and valve disc detachment
Prevention and elimination methods: Do not open too high, and repair or replace the diaphragm in a timely manner after it falls off.
② Cause: The connecting pin between the valve stem and valve disc falls off or breaks due to wear and tear
Prevention and elimination methods: Do not exceed the top dead center when opening, and repair promptly after detachment.
③ Cause: Wear and jamming at the connection between the movable valve stem nut, valve cover, and valve stem
Prevention and elimination methods: Regular cleaning, application of graphite and molybdenum disulfide dry powder for lubrication on moving parts; The fluorine diaphragm structure can add a small amount of lubricating grease to the active parts.
Qinhuangdao Victor Product Maintenance Scope: Proficient in various analytical instrument maintenance, laser scanner maintenance, thickness gauge maintenance, testing instrument maintenance, quality testing instrument maintenance, electronic measuring instrument maintenance, precision measuring instrument maintenance, and other testing instrument maintenance. Proportional valve maintenance, servo proportional valve maintenance, centrifuge maintenance, industrial electronics maintenance, motor maintenance, motor maintenance, hydraulic and pneumatic maintenance, pump valve maintenance, diaphragm valve maintenance, server maintenance, controller maintenance, inverter maintenance, frequency converter maintenance, sensor maintenance, servo amplifier maintenance, manual controller maintenance, photometric converter maintenance, sampler maintenance, DC speed controller maintenance, flow controller maintenance, circuit board maintenance, PLC maintenance, HMI maintenance, touch screen maintenance, display maintenance, power module maintenance, switch power supply maintenance, DC power supply maintenance, energy meter maintenance, liquid level meter maintenance, flowmeter maintenance, grating maintenance, infusion pump and other equipment maintenance.