Page 41 - SKF-bearing-housings

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Sealing solutions

Table 6
Corrosivity categories 1)
Corrosivity Examples of typical environments in a temperate climate
category Exterior Interior
C1 – Heated buildings with clean atmospheres, e.g.
(very low) offices, shops, schools, hotels.
C2 Atmospheres with low levels of pollution. Unheated buildings where condensation may
(low) Typically inland rural areas. occur, e.g. depots, sport halls.
C3 Urban and industrial atmospheres with Production rooms with high humidity and some
(medium) moderate levels of sulphur dioxide. Coastal air pollution, e.g. food-processing plants,
areas with low salinity. laundries, breweries, dairies.
C4 Industrial and coastal areas with moderate Chemical plants, swimming pools, coastal
(high) salinity. ship- and boatyards.
C5-I Industrial areas with high humidity and Buildings or areas with almost permanent
(very high, aggressive atmosphere. condensation and with high pollution.
industrial)
C5-M Coastal and offshore areas with high Buildings or areas with almost permanent
(very high, salinity. 2) condensation and with high pollution.
marine)

1) In accordance with ISO 12944-2.
2) In hot, humid coastal areas, the mass loss or thickness loss can exceed the limits of category C5-M and special precautions
should be taken when selecting protective paint systems.

Table 7
Converting circumferential speed limits to rotational speeds
Shaft diameter Rotational speed
at the seal lip for circumferential speed limits
2 m/s 4 m/s 7 m/s 8 m/s 12 m/s 13 m/s
mm r/min

20 1 910 3 820 6 680 7 640 11 460 12 410
25 1 530 3 060 5 350 6 110 9 170 9 930
30 1 270 2 550 4 460 5 090 7 640 8 280
35 1 090 2 180 3 820 4 370 6 550 7 090
40 950 1 910 3 340 3 820 5 730 6 210
45 850 1 700 2 970 3 400 5 090 5 520
50 760 1 530 2 670 3 060 4 580 4 970
55 690 1 390 2 430 2 780 4 170 4 510
60 640 1 270 2 230 2 550 3 820 4 140
65 590 1 180 2 060 2 350 3 530 3 820
70 550 1 090 1 910 2 180 3 270 3 550
75 510 1 020 1 780 2 040 3 060 3 310
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