Composite plummer block housings for the SKF Food Line
Composite plummer block housings for the SKF Food Line are used in the unit series listed in table 1
. The units incorporate stainless steel insert bearings or insert bearings with zinc-coated rings, both types filled with a food-grade grease. The housings cannot be ordered as separate products.
The composite housings for the SKF Food Line are strong, yet lightweight and chemically resistant. Their hygienic design features make them particularly well-suited for following the highest food safety standards.
The housings remain highly stable dimensionally and maintain their expected physical properties, despite repeated operational and washdown cycles. Particularly in wet environments, the housings are more reliable compared to other materials.
The composite material is reinforced polypropylene, chosen for its dimensional stability and chemical resistance to detergents and contaminants (table 2
). Importantly, polypropylene is hydrophobic, distinguishing it from conventional composite housing materials.
The housings feature 40% long glass fibre reinforcement, to reduce the tendency of the housings to creep under temperature and load.
The external surface finish is comparable to food industry requirements for the internal surface finish on hygenic tubing and piping.
On the housing base, a food-grade rubber forms the base seal. The rubber is selectively overmoulded with the composite of the housing to create an effective seal. As the housing is tightened down, the overmoulded rubber deforms, thereby providing the base seal to the mounting frame.
Composite plummer block housings for the SKF Food Line have no relubrication feature and are available in two different designs:
P2BC series (fig. 1)
→ oblong bolt holes, reinforced with austenitic stainless steel inserts
P2BTC series (short base, fig. 2)
→ threaded austenitic stainless steel inserts in the support base
End covers and back seals
To protect the bearing arrangement at the end of a shaft, and to avoid the possibility of an accident caused by an exposed shaft end, composite plummer block housings for the SKF Food Line are able to accommodate ECB end covers (fig. 3).
If not used with sealed units (designation suffix DFH), end covers are supplied as accessories and must be ordered separately. The designations together with the distance A5 that the end cover protrudes from the housing (fig. 4) are listed in the product tables:
The complete assortment of end covers for insert bearing housings and units is listed in the product table.
ECB end covers are made of thermoplastic polyurethane (TPU), have good resistance to most chemicals and can withstand operating temperatures up to 100 °C (210 °F)
. They are installed in the interlocking areas of the housing (→ End covers
To protect the bearing arrangement from shaft-side contamination, composite plummer block housings for the SKF Food Line can accommodate back seals. These back seals are only available with sealed units (designation suffix DFH), which already have an end cover (fig. 5