What should a fire team leader expect portable fire pumps to be able to do?
Published: 01 April, 2006
Aidan Turnbull spoke to Michael Mills to get the answers.
WHAT SHOULD A PUMP BE ABLE TO DO?
A portable pump must be able to perform three different functions:
(1) Relay pumping. Depending on the layout it is essential that pumps in a relay chain can accept inlet pressures as high as 3 or 4 bar. Generally only pumps made specifically for fire and rescue applications have pump casings that can withstand inlet pressures this high without the risk of failure.
(2) Feeding one or more fire hoses from a hydrant or reservoir. In practice fire fighters are unlikely to run more than 4 hoses at one time from one pump and the old JCDD/30 standard pump which can supply up to 6 hoses is considered unnecessary particularly as it is heavy and large compared to modern air-cooled pumps.
WHAT IS THE IDEAL WEIGHT/SIZE OF A PORTABLE PUMP LIKELY TO BE CARRIED ON A RESCUE TENDER?
Limitations in space and weight on fire appliances have led some fire services to replace large portable pumps (designed to comply with JCDD/30) with smaller models without compromising operational performance. The lower weight and more compact size of the Angus Fire range of air-cooled pumps make them ideal for meeting the demands of a modern fire service. The weights and sizes of the latest Angus Fire aircooled pump models range from 58 to 89 Kg. However, in more traditional water-cooled engined pumps the heat exchanger, the water and the water jacket around the engine all add weight and size. As a result air-cooled engines are gaining popularity.
Flow l/min @ 6bar Number o f hoses We ight kg Cube m 2
Angus LW800 850 4 89 0.18
Angus LW1300* 1,520 7 107 0.24
(3) Salvage pumping. In salvage applications such as pumping out a cellar, supply pressure is not critical. The chart below shows the predicted time taken for three different sizes of pump to pump out a cellar 4m x 3m x 3m deep.
Set up and break down time Pumping time Total time to pump dry:
Angus LW1300 15 + 10 mins 9 mins 34 mins
Angus LW900 15 + 10 mins 12 mins 37 mins
Angus LW500 15 + 10 mins 17 mins 42 mins
SHOULD PORTABLE PUMPS BE MAINTENANCE-FREE?
No pump is completely maintenance-free. However, pumps manufactured to the highest professional standards using top quality materials come close to being maintenance-free.
Air-cooled industrial engines are now available in portable pumps which offer a degree of reliability and simplicity never available before. Easy to maintain and lightweight, these power units avoid the complexity, weight and bulk of engines derived from cars.
WHAT LEVELS OF DEBRIS IN THE FLOW SHOULD THEY BE ABLE TO COPE WITH?
It is clear from this that set-up time plays a Nearly all water pumps for fire and rescue services more important role than the actual pumping are centrifugal pumps. Only centrifugal pumps time and a larger pump does not necessarily save offer the combination of pressure, flow and as much time as its size would indicate team leader expect to be able to do? efficiency required for fire fighting and flood relief operations and have the ability to handle dirty water when necessary. Generous clearances between the impeller and the body, and the water ways inside the impeller, allow dirt and stone particles to pass through the pump without damage. In addition, all Angus Fire pumps are fitted with an inlet filter sized to eliminate all particles that will not pass through the impeller.
DOES IT MAKE A DIFFERENCE IF PUMPS ARE PUMPING SEAWATER AS OPPOSED TO FRESH?
When pumping seawater gunmetal pump bodies and impellers manufactured from marine grade LG2 alloy bronze (optional on most Angus Fire models) should be used. However, it is possible to pump salty or corrosive water provided care is taken to flush the pump thoroughly after use.
THE ESSENTIAL PUMP PARTS: SHOULD THESE BE GALVANISED METAL, GUNMETAL OR BRONZE? WHAT IS RECOMMENDED?
Angus Fire pumps are manufactured from high grade cast aluminium to reduce weight. Cheaper pumps, mainly used in the building trade, are made from lower grade aluminium. Angus Fire lightweight pump bodies are machined from grade CC601 aluminium castings with the following composition: Silicon (6.5-7.5%), Iron (0.20%), Copper (0.05%), Manganese (0.05%), Zinc (0.05%), Titanium (0.20%) and Aluminium (remainder). In addition, portable pumps designed for professional fire fighting require a frame that is more robust than builders/trash pumps and manufactured from high quality materials that are both strong and resistant to corrosion such as SS304.
WHAT ARE THE MAIN METHODS BY WHICH PORTABLE PUMPS ARE ENERGISED? (VEHICLES, PORTABLE GENERATORS, HYDRAULIC POWERED ETC?)
The only motive power available in practice for a portable pump for use by fire and rescue professionals is a petrol or diesel engine. Electric power is either dependent on a convenient supply, making the pump not truly portable or needs heavy batteries which makes the pump either very heavy or with a limited duration before the battery runs out. IF YOU COULD OFFER TWO TIPS ON CHOOSING THE RIGHT PORTABLE PUMP FOR A FIRE SERVICE, WHAT WOULD THEY INCLUDE?
On pumping capacity & Size?
Simplicity, lightweight and compact size are more important than a large flow at a high pressure. Modern pumps need to fit small lockers and be easy to handle. Air cooled petrol engined pumps generally fulfil this criteria well. Flows of 700 to 800 l/min at 7bar with a good salvage flow (1,800 l/min) will meet most fire and rescue applications.
Petrol or diesel?
Petrol engines are generally much lighter than diesels and are preferred for portable fire pumps. However, some applications, typically refineries, require diesel engines.
