AUTOMATIC FIRE PUMP PRIMING SYSTEM – MULTI-LOCATION
A Trident Model #31.011.23 automatic multi-location air operated priming system shall be installed. The unit shall be of all brass and stainless steel construction and designed for fire pumps of 1,250 GPM (4,690 LPM) or more. Due to corrosion exposure no aluminum or vanes shall be used in the primer design. The primer shall be three-barrel design with ¾” NPT connection to the fire pump.
The primer shall be mounted above the pump impeller so that the priming line will automatically drain back to the pump. The primer shall automatically drain when the panel control actuator is not in operation. The inlet side of the primer shall include a brass ‘wye’ type strainer with removable stainless steel fine mesh strainer to prevent entry of debris into the primer body.
Performance, Safety, and NFPA Compliance
The priming system shall be capable to a vertical lift to 22 inches of mercury and shall be fully compliant to applicable NFPA standards for vertical lift. The system shall create vacuum by using air from the chassis air brake system through a three-barrel multi-stage internal “venturi nozzles” within the primer body. The noise level during operation of the primer shall not exceed 75 Db.
Air Flow Requirements
The primer shall require a minimum of 15.6 cubic foot per minute air compressor and shall be capable of meeting drafting requirements at high idle engine speed. The air supply shall be from a chassis supplied ‘protected’ air storage tank with a pressure protection valve. The air supply line shall have a pressure protection valve set between 70 to 80 PSIG.
Automatic Primer Control
The 12 volt primer control shall be an “automatic” type, with a pump panel three-way switch to operate an air solenoid valve. The panel switch shall operate a 12-volt solenoid to direct air pressure from the air brake system to prime the pump. To prevent freezing, no water shall enter the primer valve control.
A vacuum gauge 2” in diameter, with graduations from zero to 30 feet, shall be installed in the primer control panel. The gauge shall be physically connected to the vacuum side of the primer and read only when the primer is running so it will never see or be subject to damage from high pump intake pressures.
The automatic priming switch shall have three positions as follows:
Three (3) additional "push to prime" remote primer controls shall be installed on the panel for the specified additional intakes. The additional controls shall operate the air primer to pre-prime and may be used to remove air from the auxiliary intake piping and hose, while the fire pump is operating. To prevent freezing, no water shall enter the primer valve control.
To reduce the electrical power requirements on the fire apparatus the priming system shall be air powered. The system shall not require annual tear-down and maintenance, an electric motor, lubrication, belt drive, or clutch assembly. The maximum current draw shall not exceed 0.5 amps during operation.
The primer shall be covered by a five (5) year parts warranty.
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