The standard for brass windmill pumps

The heart of the windmill pumping system is the pump. If this part of the system is not well built then maintenance will be both costly and annoying. The Alderdice company has been producing quality brassware for over 100 years.

The Flush Cap Bore Pump

Alderdice Flush Cap Pump.GreyAlderdice Bore Pumps have flush caps enabling them to be lowered or raised from the bore without fouling inside the bore casing. This means the largest size pump can be fitted inside the bore casing.


  • Casting made from Leaded Gun Metal
  • 3.3mm cold drawn Brass cylinder
  • Two high quality tanned leather buckets (Nitrile and Neoprene are optional)
  • Nitrile faced valves on both the Plunger and Bottom Valve (Brass to brass valves also available)
  • Heavy Cages to withstand years of shock loads
  • "O" rings to seal end caps
  • 7 Pump sizes
  • Two stroke lengths
  • Clearance at each end of the stroke
  • Long threads


Pump Size Stroke Length Pipe Size (Suction & Discharge) Plunger Rod Bore Casing Nett
Standard Optional Size Weight
2" (50mm) 8" or 12" 1.1/2" 1.1/4" 1/2" 4"  
2.1/4" (56mm) 8" or 12" 1.1/2" 1.1/4" 5/8" 4"  
2.1/2" (65mm) 8" or 12" 1.1/2" 1.1/4" 5/8" 4"  
2.3/4" (70mm) 8" or 12" 2" 1.1/2" 5/8" 4"  
3" (75mm) 8" or 12" 2" 1.1/2" 5/8" 4"  
3.1/2" (90mm) 8" or 12" 2.1/2" 2" 3/4" 5"  
4" (100mm) 8" or 12" 2.1/2" 2" 3/4" 5"  

Differential Compensator (Diff. Heads)

Alderdice Diff Comp.Grey

The Differential Compensator is used where the delivery tank is higher than the delivery tee beneath the windmill. They consist of Differential Cups facing downward in a brass tube. The Differential Cups are designed to seal the water and stop leakage from the top of the pumping column. The Differential Compensator is usually fitted with a Compensator Centraliser to ensure the pump rod is kept straight and central in the compensator barrel.

Alderdice Differential Heads are made in two sizes, 1.3/8" (35mm) internal diameter and 1.3/4" (44mm) internal diameter, the barrels are made from 3.3mm thick brass tubing.

The 1.3/8" I.D. Differential Head has a 1.1/4" BSP thread cut on both ends of the barrel. The plunger has three leather cup buckets, the rod is 5/8" Whitworth. Caps are available screwed 1.1/4" B.S.P. or 1.1/2" B.S.P.

The 1.3/4" I.D. Differential Head has a three leather cup bucket plunger, with 5/8" W. rod. It is fitted with one cap (single end) or two caps (double end), screwed 1.1/4" B.S.P. or 1.1/2" B.S.P. or 2" B.S.P.

Strokes: 8" (200mm) & 12" (300mm) - Longer to order.

Foot Valve

Alderdice Foot Valve.GreyAlderdice Foot Valves are made of Gunmetal Bronze. They have a nitrile faced valve giving a positive non-return seal. The barrel shaped body allows an easy flow around the valve.

Sizes available