Batescrew Axial Flow Pumps
Lubrication Options

The lineshaft bearings of axial flow pumps are lubricated by either water or oil, according to customer preference and water quality.
The initial-cost comparison between water and oil lubrication depends upon the overall length of the pump.  On long-column pumps, the oil lubricated system tends to be lower priced, whereas water lubrication costs less on short pumps.
Oil Lubrication.
Oil lubrication gives increased bearing life and is essential when grit or suspended solids are to be pumped.  Batescrew supply a suitable biodegradable oil, which is drip-fed from above the pump.
The main shaft is enclosed within a steel lube-tube, which carries multiple bronze bearings.  The lube-tube is hot dip galvanised, internally and externally, protecting the lubricant from contamination by the products of condensate corrosion.
The lowest bearing, located beneath the impeller, is bronze and is grease lubricated via a tube extending down from the pump mounting plate at the discharge head.
Adjustable drip-feeders are fitted as standard.  Solenoid operated drippers are available for use with automatic start systems, allowing lubrication to commence fifteen minutes prior to starting the pump.
Water Lubrication.

Clear sand-free potable water is necessary for water-lube. 
Water lubricated pumps have stainless steel shafts running in EPDM rubber bearings and are fitted with either packing glands or mechanical seals, depending on the level of pressure to be expected in the discharge head.
Bearing Spacing.
Maximum spacing of the lineshaft bearings is limited to 1.22 metres, ensuring that the design stress of the shaft is in compliance with ‘Fixed Fire Pump Standard AS2941'.  This often means ‘more bearings per pump on Batescrew pumps'.

Shafts are reversible, for extra wearing life.
Water-cooled Thrust Bearing.
Thrust bearings, located at the top of the drive column, are held in a water-jacketed cast iron housing.  Cooling water is tapped from the pump discharge, circulates through the bearing housing and is returned to the discharge line.  If a pump has a long drive column extension (as for underground discharge) and low operating head, there may be insufficient pressure for cooling water to reach the thrust bearing.  In such cases a special air-cooled bearing assembly or a separate thermosyphon cooling system may be specified.