Daily maintenance methods for sanitary electric sealed butterfly valves:
1、 Daily inspection and cleaning
Appearance and sealing inspection: During daily inspections, check whether there are residual media or pollutants attached to the surface of the valve body, with a focus on observing whether there is leakage at the flange connection and valve stem sealing parts. It is recommended to use alcohol or non corrosive cleaning agents to wipe the surface to avoid scratching with hard objects that may cause excessive surface roughness.
• Electric actuator status: Check if the power circuit, indicator lights, and control signals of the actuator are normal, record the range of current fluctuations during valve opening and closing actions, and abnormal fluctuations may indicate increased mechanical resistance or seal wear.
Sealing surface cleaning: After each production, rinse the sealing surface of the valve seat and butterfly plate with sterile water or steam to prevent medium crystallization or microbial growth. For soft sealed butterfly valves, it is necessary to avoid direct impact of high-temperature steam on the sealing material.
2、 Lubrication and anti-corrosion management
Lubrication of transmission components: Add food grade grease (such as NSF H1 certified products) to moving parts such as valve stems and bearings every month, and remove excess grease after lubrication to prevent contamination of the medium.
Sealing component maintenance: Check the elasticity and wear of the sealing ring every quarter, and prioritize the use of sanitary grade seals made of EPDM or PTFE materials. If the indentation depth on the sealing surface exceeds 0.1mm, it should be replaced in a timely manner.
Anti corrosion treatment: For valves that have been exposed to acidic and alkaline media for a long time, a polytetrafluoroethylene coating should be sprayed on the valve cavity every six months, and the integrity of the passivation film on the electropolished surface should be checked.
3、 Periodic functional verification
Sealing performance test: Conduct a pressure holding test every quarter, close the valve and pressurize it to 1.1 times the design pressure. If there is no leakage after holding for 10 minutes, it is considered qualified. It is recommended to use pure water or inert gas as the testing medium.
Calibration of actuator: Verify the linear relationship between valve opening and feedback signal annually through a standard signal generator. If the error exceeds ± 2%, recalibrate the positioning module.
CIP/SIP compatibility verification: Regularly simulate online cleaning (CIP) and sterilization (SIP) processes to confirm the sealing reliability of valves under high temperature (≥ 121 ℃) and strong acid and alkali cycling.
4、 Key points for maintenance under special working conditions
High viscosity medium working condition: Rinse the flow channel after each use to prevent residual solidification of the medium. It is recommended to shorten the lubrication cycle to 15 days per cycle and choose high permeability lubricants.
• Aseptic production environment: Maintenance operations need to be completed in a clean area, and disassembled parts need to be sealed in double-layer sterilization bags. Before reassembly, surface microbial sampling testing is required.
5、 Storage and deactivation maintenance
When not in use for a long time, the medium inside the valve chamber should be emptied and food grade antifreeze should be injected, and the electric actuator should be sealed for moisture resistance. Before reactivation, a 48 hour no-load operation test is required.