Fluorine lined ball valve is a valve that uses a ball with a circular through-hole as the opening and closing element. The ball rotates around the centerline of the valve body along with the valve stem to achieve valve opening and closing. Fluorine lined ball valves are professionally designed to control the opening and closing of various highly corrosive media, and are widely used in industries such as petroleum, chemical, dyeing, pesticide, acid and alkali production. They are currently the ideal choice for anti-corrosion valves.
1、 Installation precautions
1. Preparation before installation
(1) Check valve parameters: Before installation, carefully check the model, specifications, pressure rating, material and other parameters of the fluorine lined ball valve to ensure that it fully matches the design requirements of the pipeline system, and to avoid valve damage or medium leakage caused by parameter mismatch. At the same time, confirm that the flow direction identification of the valve is consistent with the actual flow direction of the medium. Fluorine lined ball valves usually have bi-directional flow, but some special operating condition valves have clear flow direction requirements that must be strictly followed.
(2) Check the valve status: After opening the box, check whether the valve appearance is intact, whether there are defects such as bulges, cracks, and detachment in the lining layer, whether the valve stem rotates flexibly, whether the ball opens and closes smoothly, and whether there are scratches or impurities attached to the sealing surface. If any damage or abnormality is found, it is necessary to contact the manufacturer in a timely manner for handling, and forced installation is not allowed.
(3) Cleaning up pipeline impurities: The pipeline ports where valves are installed need to be cleaned to remove welding slag, rust, oil stains, debris, etc., to prevent impurities from entering the interior of the valve and scratching the lining layer or sealing surface, which may affect the sealing performance and valve service life. At the same time, ensure that the flange surface of the pipeline is flat and free of deformation, and that the selection of sealing gaskets meets the characteristics of the medium and pressure temperature requirements.
2. Installation process specifications
(1) Avoid strong installation: During installation, it is strictly prohibited to use strong alignment, tapping valve flanges, or other methods to prevent deformation of the valve housing and damage to the lining layer. It should be ensured that the coaxiality between the valve and the pipeline is consistent. When connecting the flange, the bolts should be tightened evenly, using a diagonal step-by-step tightening method to ensure that the flange surface is evenly stressed and avoid damage to the lining due to excessive local pressure.
(2) Reserved operating space: Sufficient operating and maintenance space should be reserved at the installation position of the valve, especially for manually driven fluorine lined ball valves. It is necessary to ensure that the rotation of the valve stem is not obstructed and there is no interference when operating the handle or handwheel; For pneumatic and electric driven valves, it is necessary to reserve maintenance space for the actuator and ensure that the installation direction of the actuator meets the operational requirements.
(3) Stay away from heat and vibration sources: The heat resistance of fluorine lined materials is clearly limited (different lining materials have different heat resistance ranges, such as PTFE at -200 ℃~180 ℃). When installing, avoid placing the valve near high-temperature equipment or heat sources to prevent the lining layer from aging or deforming due to overheating. At the same time, try to stay away from equipment with strong vibrations. If unavoidable, shock absorbers should be installed on the pipeline to reduce the impact of vibration on valve sealing performance and structural stability.
(4) Correctly connect the driving device: For pneumatic and electric fluorine lined ball valves, when installing the driving device, it is necessary to ensure that the valve stem is coaxial with the output shaft of the actuator, the connection is firm and not loose, and to avoid valve stem wear and jamming caused by different shafts. After the connection is completed, a no-load trial run is required to check whether the actuator action is accurate and smooth, and whether the signal feedback is normal.
3. Installation requirements for special working conditions
(1) Corrosive medium pipelines: When installing valves on pipelines transporting highly corrosive media, corrosion-resistant gaskets (such as PTFE gaskets) should be used for flange connections, and stainless steel or corrosion-resistant alloy materials should be selected for bolts to avoid loosening the connection due to corrosion. At the same time, protective measures should be taken around the valve to prevent the leakage of corrosive media from causing damage to the surrounding equipment and environment.
(2) Low temperature or high temperature conditions: When installing under low temperature conditions, attention should be paid to the low-temperature brittleness of the fluorine lining material to avoid collision with the valve during installation; Under high temperature conditions, it is necessary to confirm the thermal expansion of the pipeline and install compensators if necessary to prevent additional stress on the valve caused by thermal expansion and contraction of the pipeline, which may damage the lining layer and sealing structure.
2、 Maintenance precautions
1. Daily inspection and maintenance
(1) Sealing performance inspection: Regularly check whether there is any medium leakage at the flange connection, valve stem packing box and other parts of the valve. If a leak is found, for the flange connection part, the bolts can be tightened appropriately (with even force); For the leakage of the packing box, the bolts of the packing gland can be adjusted. If the packing ages and fails, it should be replaced in a timely manner. When replacing, PTFE packing or other corrosion-resistant packing compatible with the medium should be selected.
(2) Operational flexibility check: Manual valves require regular rotation of the handwheel to check if the valve stem rotates flexibly and if there is any jamming; Pneumatic and electric valves need to undergo regular no-load and load test runs to check the response speed and stability of the actuator, as well as whether the signal transmission is normal. If problems such as jamming or delay are found, the cause should be promptly investigated (such as valve stem corrosion, lining layer deformation, actuator failure, etc.).
(3) Appearance and environmental maintenance: Keep the valve surface clean and avoid dust, oil stains, and corrosive media from adhering. For fluorine lined ball valves installed outdoors, measures should be taken to prevent rain, sun, and freezing to prevent rainwater from seeping into the actuator, damage to the lining layer caused by low temperatures, and accelerated aging of the lining in high temperature environments.
2. Regular maintenance and upkeep
(1) Lubrication and maintenance: Regular application of lubricant is required for moving parts such as the connection between the valve stem and packing box, and the connection between the valve stem and the actuator. Lubricants should be of a type that is compatible with the medium and has strong corrosion resistance (such as fluorine grease), to avoid the use of ordinary lubricants being corroded and ineffective by the medium, and to prevent lubricant contamination of the medium.
(2) Lining layer inspection: Regularly inspect the valve lining layer. If defects such as bulges, cracks, detachment, and wear are found in the lining layer, the valve should be shut down for maintenance or replaced in a timely manner. After the lining layer is damaged, the medium will directly corrode the valve shell, causing valve failure and even leading to safety accidents.
(3) Seal replacement: Seals (such as valve seat seals and flange gaskets) are vulnerable parts and need to be replaced regularly according to the operating conditions and usage time. When replacing, it is necessary to choose sealing components that are consistent with the original specifications and compatible with the material. Before installation, impurities on the sealing surface should be cleaned to ensure that the sealing surface is flat and avoid leakage caused by improper installation of the sealing components.
3. Fault handling and taboos
(1) Do not forcefully close or open: When the valve encounters difficulties in opening and closing, it is strictly prohibited to forcefully turn the handwheel or start the actuator to avoid causing the valve stem to bend, the ball to deform, and the lining layer to be damaged. The cause should be investigated first, such as medium crystallization blockage, valve stem rust, lining aging, etc., and targeted treatment should be carried out (such as valve cleaning, rust removal, component replacement, etc.).
(2) Avoid medium overheating and overpressure: Strictly control the operating conditions of the valve to prevent the medium temperature and pressure from exceeding the rated range of the valve. Overheating can cause aging and decomposition of fluorine lining materials, while overpressure can damage the sealing structure and valve housing, shorten the service life of valves, and even lead to safety accidents.
(3) Proper cleaning and storage: If the valve is not in use for a long time or the medium is prone to crystallization or solidification, it is necessary to rinse the inside of the valve with a compatible cleaning medium before use to remove residual medium and prevent medium crystallization from blocking the valve or corroding the lining layer. When storing, the valve should be in the closed state to avoid damage to the ball and sealing surface from external forces. At the same time, it should be stored in a dry, ventilated, and non corrosive gas environment to avoid aging of the lining layer.
(4) Professional maintenance requirements: Disassembly and maintenance of valves must be carried out by professional personnel, and collision and scratching of the lining layer and sealing surface must be avoided during disassembly. After the maintenance is completed, pressure tests (such as water pressure tests and air tightness tests) need to be conducted to ensure that the sealing performance and structural integrity of the valve meet the requirements before it can be put back into use.