For static seals, there are usually only two forms: gaskets and sealing rings, and sealing rings are used in the form of O-rings; for dynamic seals, chemical pumps rarely use packing seals, and mainly use mechanical seals. Mechanical seals are divided into single-end and double-end, balanced and unbalanced types. Balanced type is suitable for sealing high-pressure media (usually refers to pressure greater than 1.0 MPa), and double-end mechanical seals are mainly used for high-temperature, easy-to-crystallize, viscous, particle-containing and toxic volatile media. Double-end mechanical seals should inject isolation liquid into the sealing cavity, and its pressure is generally 0.07~0.1 MPa higher than the medium pressure.
The material of chemical pump static seals is generally fluororubber, and polytetrafluoroethylene materials are used in special cases; the material configuration of mechanical seal dynamic and static rings is more critical, and it is not the best for cemented carbide to cemented carbide. The high price is one aspect, and it is not reasonable that there is no hardness difference between the two, so it is best to treat them differently according to the characteristics of the media.
Equipment initial use management
The main contents of initial use management are:
(l) Adjustment and trial run of equipment in the initial use to make it achieve the functions expected by the original design.
(2) Technical training for operators on the use and maintenance of equipment.
(3) Observe, record and analyze the changes in the operating status of equipment in the initial use.
(4) Improvement measures to stabilize production and improve equipment production efficiency.
(5) Carry out information management in the initial use, formulate information collection procedures, make original records of initial failures, fill in the equipment initial use appraisal and commissioning records, etc.
(6) The using department shall provide various original records, including actual start-up time, use range, use conditions; component damage and failure records; early failure records and other original records.
(7) Study typical failures and component failures, and propose improvement measures and countermeasures.
(8) Propose reasonable improvement suggestions for defects in the original design or manufacturing of equipment, and take measures for improvement maintenance.
(9) Conduct technical and economic analysis and evaluation of the costs and effects in the initial use.
(10) Analyze and process the information collected in the initial use.