Water (Fire) Pump Engine

Fire pump engines Parameters

FAWDE offers a bespoke programme for the maintenance, servicing, repair and remanufacture of diesel engines used in fire pump drive applications. These are diesel engines designed for stationary emergency standby fire pump service.

Fire engine gasoline engine vs diesel engine

Diesel fire pump engines starting speed is higher than gasoline engine starting speed. As the fire truck diesel engine is near the end of the compression stroke, diesel fuel to mist sprayed into the cylinder, and compressed air to form a mixture and spontaneous combustion. In order to make the temperature of the compressed air is higher than the temperature of diesel fuel (about 330 degrees), and to ensure a good quality of fuel injection, the need for higher starting speed (200-300 rpm); and gasoline engine is in the carburetor to start the formation of the mixture, the mixture is formed under good conditions, and its combustion is ignited by the electric spark, so the starting speed is lower (30-60 rpm).

Fire truck diesel engine than gasoline engine compression ratio is large. For example, 160F diesel engine compression ratio of 20:1, 1E45F gasoline engine compression ratio of 7.63:1, compression ratio of large starting resistance, so the diesel engine than gasoline engine is difficult to start.It can be seen that the diesel engine not only needs a larger starting torque than the gasoline engine, and the need for higher starting speed.

Main structure and working principle of engine

cylinder block

Air cylinder ,adopting long men structure, HT250 casted, is the basic skeleton of engine.

When installing the main bearing, it can't arbitrarily interchange and the direction cannot be reversed. The main bearing assembly should be in the thread before bolts and head bearing surface oil, tighten bolts adding a few not allow a tight in place, we should start, once among three times to take turns evenly on both ends, tighten the program as follows to :

First tightened torque: 60-80 N.m

second tightened torque:: 160-180 N.m

third tightened torque:: 180-260 N.m

Every tightened, turning the crankshaft to check for flexibility.

Finally, ensuring bolts for checking the torque well at 180 N.m - 260 N.m.

diesel fire pump engines are designed to help power you through a building disaster. Whether it's a small copier fire in your office or a major heat event on an oil platform, turn to us for fail-safe products that will leave you high and dry. Our team offers you customizable expertise backed by the reputation and reliability of a world leader in engine technology.

Many of our fire pump drive engines are Underwriters Laboratories (UL) listed and Factory Mutual (FM) certified

FAQ for Fire pump engines

What type of drive should be used in a fire pump

diesel fire pump engines are typically driven by electric motors or diesel engines. Consideration must be given to ensure that there is enough power or enough fuel to operate these drives in the event of a fire. Engines are often used as pump drivers where there is an unacceptable risk of interruption, unreliability, unavailability or unsuitable power. 

Fire pumps can be driven by electric motors, diesel engines or steam drives. Diesel engines are often used when the electrical supply to the property is unreliable or of insufficient capacity. They are also used by customers who require a primary electric motor driven fire pump system and a redundant diesel engine driven fire pump system, or for properties that require a redundant system due to their seismic zone or height. 

Diesel engines have been used in light and heavy duty applications for decades. Diesel engine drives are commonplace for larger generating sets. While gensets and fire pump systems may use similar diesel engines, they are designed and installed very differently in certain critical areas.

FAWDE is responsible for ensuring that diesel engines are suitable for fire service. Owner and installation manuals must be reviewed and followed to ensure trouble-free operation and to maintain any warranty policies. In order for a diesel engine to operate properly, it needs to be able to feed, breathe and cool itself. 

The fire pump diesel engine needs to deliver clean fuel to the engine's fuel injection pump, usually under gravity pressure. The fuel supply tank should be positioned so that the connection to the engine's fuel supply pipe is no lower than the height of the engine's fuel supply pump. The engine manufacturer's fuel pump hydrostatic head pressure limit must not be exceeded when the fuel in the tank is at its maximum.

Fire pump diesel engine fuel storage

In areas prone to icing, the tank must be located in a fire pump house. Dedicated fill and vent ports and a visible and monitored fuel level gauge are required. 

In today's market there are two types of tank available: single-wall tanks and double-wall tanks. While single-walled tanks are initially cheaper, an overflow containment system must be provided for the full tank capacity. By design, double-walled tanks include an overflow containment device. Their holding space must be monitored for leaks from the inner walls. The venting of the double-walled tank interstitial space must not be collectively piped with the venting of the main tank compartment. 

The minimum capacity of a tank is determined by a simple formula: 1 gallon per rated horsepower plus 5% for the sump and 5% for expansion. While you should install at least the minimum size tank, it is not always a better idea to provide a tank that is too large. Diesel fuel has a shelf life and requires regular fuel quality testing.

Diesel fire pump engines safety

In a typical installation, the fire pump system will run for an average of 30 hours or less per year. The tank needs to be refilled as required to keep it close to full capacity at all times; however, it should not be less than two-thirds of full capacity. This ensures that the engine is always able to run at full capacity for the required duration. However, this may result in the fuel becoming stale.

The fuel grade required by the engine must be posted on a label on the fuel tank. The engine manufacturer has precise requirements regarding the type of fuel that must be followed. Residual fuels, domestic heating oil, drained lubricating oils, biodiesel above a certain percentage limit, No. 1 diesel, paraffin and similar fuels are not normally permitted. 

If a diesel fire pump drive is not listed for use with No. 1 diesel fuel, engines listed for use with No. 2 diesel fuel should be permitted. However, if the engine manufacturer approves the use of No. 1 diesel, the nameplate horsepower rating must be reduced by 10%.

Diesel fire pump engines exhaust system

Diesel engines require large amounts of air to be consumed and combustion gases to be processed for proper operation. The manufacturer's data sheet provides the amount of combustion air required. This amount of air must be freely available at the air filter inlet and not exceed 120 F. Depending on the particular installation location, vents, ducted fresh air or other means of access to the outside must be designed and installed.

A suitable exhaust system is required to safely handle all combustion gases. It must be transported to a safe venting location; the design and installation must comply with the engine manufacturer's installation manual, NFPA 20, municipal or other regulations, and meet the requirements of the governing authority. 

The selection of the exhaust system needs to be completed by a calculation procedure to ensure that the back pressure of the diesel engine is in accordance with the list. The type of silencer chosen, the size and length of the pipework, the number and type of fittings and other factors will all affect the minimum pipe size required. 

Exhaust system piping should be as short, insulated and protected as possible to protect personnel and minimise heat transfer to the fire pump room or other surfaces. In many current installations the exhaust system is not designed or assessed correctly. In most cases, the system works well, but the available power is compromised and damage occurs to the diesel engine. 

Diesel engines need to be installed in an environment that meets the requirements of NFPA 20 and the engine manufacturer. Typically this means maintaining an ambient temperature between a maximum of 120 F when the fire pump system is at full load and a minimum of 40 F when the fire pump system is not operating. The engine manufacturer's data sheet will provide data on the heat dissipation of the engine when running at full load. 

The 40 F value is usually based on the block heater provided on the diesel engine block. The block heater needs to be connected to a power source; my personal preference is to have the power source supplied from a standby power circuit.NFPA 20 states "Where electrical power is unreliable and there is a risk of pump house icing, standby power should be provided to maintain space heating, battery charging, engine block heating and lighting."

Cooling of a diesel fire pump engines

Cooling a running diesel engine is a key requirement. There are two ways to achieve this. As with generator sets, a large radiator with a fan to provide the required airflow for heat exchange is a perfectly acceptable method. In reality, however, this is rarely used. The amount of airflow and the ease of other processes usually make the choice a "no-brainer". 

The second method uses a heat exchanger with water from the discharge side of the fire pump to provide cooling. Because water absorbs heat much better than air, the relative size and ease of use of this method is utilised in most applications. In addition, with this method, the cooling water acts similarly to a casing relief valve. Therefore, NFPA 20 does not require the installation of a casing safety valve when using this method.

diesel fire pump engines are an excellent choice as drivers for fire pump systems; they are reliable and effective. Fuel supply and associated components, combustion air, exhaust, ventilation, operating environment, engine cooling - all of these need to be considered in the design and installation to provide a reliable and quality system.