International Options
United Kingdom

United Kingdom
Shopping Basket
Your basket is empty
About Pressurised Fresh Water Pumps
30620.jpg (4232 bytes)
The size and shape of your vessel or vehicle, and the number of water outlets you require, will determine the size of the pump and the other system components, and how much pipework you will need. This schematic diagram depicts a typical system, and shows how the components are linked.



For installations with up to 6 outlets59450.jpg (4560 bytes)

JABSCO 'Par Max' multi-diaphragm pumps are light, compact, quiet and efficient. They maintain the high reputation of the earlier PAR diaphragm pump range for reliability.

The flow of water from a JABSCO 'PAR-MAX' multi-diaphragm pump appears smooth, but actually pulsates rapidly. The pump may be noisy if mounted on a light, unsupported surface - particularly if metallic pipework is used. A solid, non-resonant mounting surface, and the use of plastic pipework, will suppress the noise.

Pump model

Output, litres/minute
(imperial gall/minute)

Recommended for:
Par Max 2.9  up to 11 litres/minute (2.4 gallons/minute) open flow galley & toilet with small diameter shower
Par Max 3.5 up to 13 litres/minute (2.9 gallons/minute) open flow galley & toilet with standard domestic shower
Par Max 4 up to 16 litres/minute (3.5 gallons/minute) open flow galley & 2 toilets with standard domestic shower
VFlo  up to 19 litres/minute (4.2 gallons/minute) open flow Jabsco's latest microchip controlled pump adjusts its speed automatically to meet demand, while maintaining a constant output pressure. It doesn't need an accumulator tank (see below), but note that systems with water storage heaters will still need an expansion tank.


For a recommendation for a plastic pipework system,  or for larger systems (i.e. - more than 6 outlets), visit Cleghorn Waring.


Accumulator Tanks

An accumulator tank is an important part of any pressure-controlled water system. Fitted close to the pump discharge, it acts as a pressure buffer, absorbing flow from the pump when demand is low, and smoothing the outlet pressure. By removing the need for the pump to run immediately an outlet is opened, it extends pump life and reduces battery drain. The larger the accumulator tank, the less often the pump has to start.

The larger tanks have an appreciable water storage capacity - approximately half the nominal tank volume. The larger your pressurised system, or the higher the demand for water, the larger the accumulator tank should be. For minimum wear and tear on your pump, fit the largest accumulator tank you can.

Accumulator tanks are also used as expansion vessels in conjunction with water storage heaters.

Water Storage Heaters

Even the smallest water-cooled marine engine discharges large amounts of 'waste' heat. This rejected energy won't help to propel your boat, but it's ideal for heating your domestic fresh water supply, and far too useful to be dumped straight overboard. Why waste it? With a fully-insulated C-WARM water storage heater, you can heat a full tank of water (small or large) within half an hour, and keep it usefully warm for many hours after you have stopped the engine. Visit Cleghorn Waring for more information.

Pipework and Fittings

The best plastic pipework is flexible, non-toxic, resistant to algal growth, immune from electrolysis, frost-resistant, noise-suppressing, and remarkably easy to fit, extend, alter or dismantle - visit Cleghorn Waring to find out more.

warning.gif (455 bytes)
No Jabsco pump should be used for petrol, solvents or any liquid with a flash point below 37oC( 98oF)