Preparing for installation:< /p>
- For the installation of seals, it is necessary to have an appropriate drawing;
- Before starting work, it is necessary to check the dimensions, as well as the corresponding maximum tolerances, including allowable deviations from the specified shapes and arrangements;
- all edges and shoulders on which the mechanical seal is mounted must be cleaned, rounded and have a chamfer of no more than 30 ° x 2 mm;
- Deviations of linear and angular dimensions must comply with DIN ISO 2768 tolerances;
- Surface quality must comply with EN 12756 (DIN 24960).
Remember that axial runout tolerance depends on RPM.
The extrusion resistance of elastomeric O-Rings can be greatly improved by using back-up rings.
Radial run-out of the shaft or shaft protection sleeve in the contact area of the mechanical seal surfaces for diameters < 50 mm should not exceed - 50 µm, for diameters from 50 to 100 mm - 80 µm and for diameters > 100 mm - 100 µm, according to DIN ISO 5199.
At sliding speeds < 25 m/s misalignment of the seal chamber with respect to the shaft should not exceed - 200 µm, and when using the built-in impeller due to the effect on the feed characteristic - 100 µm. For sliding speed > 25 m/s lower values apply.
Installation:
- The basic principle of mounting mechanical seals is maximum cleanliness and careful execution.
- Contamination and damage to the sealing surfaces and O-rings will affect the life of the seals.
- Protective coatings on sliding surfaces must be completely removed.
- Never apply grease to the sliding surfaces, they must be completely dry, free of dust and dirt before installation.
- It is essential that you follow the included installation instructions and the drawings exactly.
Recommendations:
Before installing the seal on the shaft or the cartridge seal in the chamber, to reduce the friction force, it is necessary to apply a thin layer of silicone grease or oil to the O-rings. Attention! This does not apply to seals with elastomer bellows.
EPDM O-rings must never come into contact with mineral oil or grease. When installing/pressing in the counter rings, protect the sliding surfaces, monitor the uniform distribution of the pressing force and lubricate the O-rings to reduce friction only with water or alcohol.
If a special threadlocker is not available, a suitable adhesive (e.g. Loctite) must be applied to the set screws after removing the grease before installation.
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