+ BROCHURE.

You can download our Axial Flow brochure here

+ APPLICATIONS.

In agriculture these pumps are used for irrigation, tail water control and on-farm storage schemes. They are used by Local Government and Semi-Government Authorities, for flood mitigation, town water supply, wastewater and environmental control projects. There are many other applications, from marine bow-thrusters to prawn farms. Batescrew 'Portax' portable pumps are part of the axial flow range.

+ PUMP SIZES.

Nineteen sizes are manufactured, pumping from 2 to 280 megalitres per day, to total dynamic heads of up to 28 metres per stage. Sizes are indicated by a two-part model number e.g. 14/16, indicating nominal diameters of impeller/column, in inches.

+ MODELS AVAILABLE ARE:

4/4; 5/6; 7/7; 7/9; 9/9; 9/11; 11/11; 11/14; 14/14; 14/16; 17/18; 17/21; 21/21; 21/24; 24/24; 24/30; 23/36; 32/42; 32/48.

+ PUMP CONFIGURATION.

As illustrated on the previous page and described below, Batescrew axial flow pumps are made in three configurations, to suit site conditions and installed cost considerations.

• Angle Application pumps are used for riverbank and storage dam installations. For river use they offer the least obstruction to river flow, less bank disturbance and require less infrastructure than vertical pumps. The flanged discharge outlet is inclined at an angle of 36 degrees to the main axis of the pump. Discharge may be either above or below ground. In the latter case an extended drive column may be fitted, keeping the power unit and pump thrust bearings above possible flood level. See also: Description; Drive Options; Dimensions; System Requirements.

• Vertical Application pumps, for non-river use, are simple to install and will cost less than angle pumps. When the depth of an excavation exceeds six metres, costs become excessive and an angle application pump should be considered. Split mounting plates allow a vertical pump to be rotated, in one hole increments of the base flange, to align the discharge outlet as required. Mounting plates are normally located immediately below the discharge head or, for below-ground discharge, may be located immediately above the head or at the top of an extended drive column. Please indicate the preferred location of mounting plates when ordering. See also: Description; Drive Options; Dimensions; System Requirements.

• Columnless pumps are the lowest cost version, used in wells or pre-fabricated structures. The cost of discharge Column and Head is avoided, although cost of the well or sump may be higher. A sliding non-return valve may be fitted to the drive shaft column, to seal on the upper flange of the pump body. Further details re. drive options, system requirements etc. are the same as for Vertical Application pumps at (2) above.

+ OIL OR WATER LUBRICATION.

Pump shafts may be oil or water lubricated, depending on water quality and customer preference (see Lubrication Options).

+ SPEED REDUCTION.

In some cases it will be necessary to match the optimum operating speed of a power unit, with the necessary RPM of a pump shaft. For diesel engines this may be achieved by twisted vee-belts, or by an angle gearbox of the required ratio, connected to the engine by universal shaft.

Crossed belts may be used, up to a maximum of six belts or 45 kW (60 hp). For electric motors, reduction may be achieved mechanically by vee-belts or angle gearboxes, or may be achieved electrically by a Variable Speed Drive unit. The latter option allows for the use of direct-coupled motors, avoiding belts, gearboxes and universal shafts.

+ FUEL COSTS.

Fuel costs can be calculated for any proposed installation, based on pump size, choice of impeller, system layout, required head & flow rate and the on-site cost of fuel. This calculation is normally done, as a free service, by the Batescrew Technical Services department. Calculations are made for both diesel and electric drives, to assist in drive selection. See Design Calculation Service.

+ Construction Materials

Impellers are cast Aluminium Bronze, enclosed within Stainless Steel Running Rings. Intake Bellmouth Housings and Stator Housings are of Cast Iron Other parts of the Column and Discharge Head are steel fabrications, hot dip galvanised.

Drive Shafts are of grade 431 Stainless Steel, for water-lubricated pumps and Bright Mild Steel (with Stainless Impeller Shafts) on oil-lubricated pumps. Lube-tube Columns, which house the bearings and lineshaft on oil lubricated pumps, are hot dip galvanised. Galvanising inside the tubes reduces contamination of lubricant by the products of condensate corrosion.Other materials, including Stainless Steel castings and Stainless fabrications, may be specified as required.

+ Pump Shaft Stress.

Maximum bearing spacing of the lineshaft is limited to 1.22 metres, ensuring that the design stress of lineshaft is in compliance with ‘Fixed Fire Pump Standard’ AS2941. This often means ‘more bearings per pump on Batescrew pumps'. Lineshafts are reversible, for extra wearing life.

+ 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.

Seven thrust bearing assemblies are available, matching pump power ratings from 18 kW (25hp) to 740 kW (992hp).These units are fitted to both Axial Flow and Turbine pumps, Thesmallest bearing, No.1, is air cooled, while all larger sizes have water cooled housings,for which pressurised cooling water is tapped from and recirculated to the discharge head.Sizes, power ratings and replacement parts are listed in the table at the foot of this page.