Combination seals (O - ring seals used for general performan
Structure device
I. performance and purpose
It consists of an anti-wear filling polytetrafluoroethylene (PTFE) ring and O - shaped rubber sealing ring. O ring provides pre-tension. It can compensate for the wear of (PTFE) square ring. Suitable for sealing of hydraulic cylinder piston. General and guide ring supporting use. Dimensions less than F40 should be in split groove.
Second, the material
PTFE+ NBR, the rubber elastomer is used in special case.
Working conditions
Working pressure: 0-40mpa
Reciprocating speed: less than 5m/s;
Temperature: for butadiene-acrylonitrile rubber o-ring NBR: - 30 ~ + 120 ℃, fluorine rubber FKM: - 20 ~ + 200 ℃
Working medium: hydraulic oil, gas, water (choose fluorine adhesive in the hydraulic oil of phosphate ester).
Iv. Design standards
This series conforms to the ISO 7425/1 standard, which conforms to GB/T15242.1-94 and GB/t15242.3-94.
O-ring installation
The following matters should be noted during the installation of o-ring:
(1) make sure the edges of the edges or the transition holes are chamfered or dull and remove burrs.
(2) check whether the sealing surface is defective.
(3) remove all processing residues.
(4) the thread on the installation path shall be fitted with a protective cover to prevent the screw-point from scraping the o-ring.
(5) for easy installation, lubricate the surface of the o-ring installation.
(6) when installing manually, do not use sharp tools, but try to use tools as effectively as possible to ensure that the o-ring is not distorted.
(7) excessive stretching of o-rings is prohibited.
(8) an o-ring made from the seal strip, which prohibits stretching at its joints.
(9) if it is installed automatically, it must be fully prepared. For example, for easy installation, it can be coated with molybdenum, graphite, talcum powder or PTFE coated on the surface of O ring.
stockpile
The seals are often stored as spare parts for a long time. In order to avoid the physical and chemical properties of the o-ring due to external factors, the elastomer is damaged and some rules should be observed in storage:
(1) store in a dry place.
(2) the temperature between + 5 ℃ ~ + 25 ℃, avoid direct contact and heat source.
(3) avoid direct exposure to sunlight or neon lights.
(4) in the original container or in the airtight container to prevent oxidation.
(5) keep away from harmful gas sources (such as ozone) to prevent elastomers from being damaged.