FIRE PUMP SETS

FIRE PUMP SETS

FIRE PUMP SETS

 

  1. General Requirements

–        The pumping unit shall meet the requirements of NFPA 20 and listed and approved by UL and FM for fire fighting use.

–        All pumps and their drivers shall be mounted on a reinforced concrete foundation of an adequate construction and dimensions.

–        All pumps shall be located in accessible locations for ease of repair and maintenance.

–        All pumps shall be constructed of materials having a pressure rating not less than 16 bar.

–        All pumps shall be provided from the factory with plugged connections for casing vent, drain and suction and discharge pressure.

–        Each pump shall be tested at the factory to provide detailed performance data and to demonstrate its compliance with the specification.

–        Each pump shall be hydrostatically tested by the manufacturer for a pressure not less than 16 bar.

–        Piping shall be supported independently of pumps nozzles to prevent piping weight or stresses from bearing on or being transmitted to the pump nozzles.

–        Drain from base plate, pump, relief valves, etc. shall be piped to the floor drain located in pump room.

–        All pipes, fittings, valves and instrumentation shall have a pressure rating not less than 16 bar unless otherwise specified.

–        Other requirements of pipe work and valves shall be as called for in this specifications.

–        All conduit for electrical work shall be heavy gauge galvanized steel.

  1. Horizontal Split Case And End Suction Pumps (electric drive and diesel engine drive)

2.1     Foundation and Setting

The pump and driver shall be mounted on a common cast iron or steel base plate adequately reinforced against deflection and provided with drip rim and bolt holes.

The pump shall be directly connected to the driver through a heavy duty flexible coupling and provided with heavy gauge coupling guard from the factory. The base plate shall be securely supported on the foundation in such a way that proper pump and driver shaft alignment will be assured.

The base plate, with pump and driver mounted on it, shall be set level on the foundation and secured with proper size anchor bolts and completely grouted in to provide a rigid non deflecting support. Pump and driver shall be aligned at the factory.

2.2     Pump Construction

The pump casing shall be of high tensile strength close-grained cast iron fitted with bonze wearing rings.

The impeller shall bronze of the enclosed type and fitted to the shaft with stainless steel key. The impeller shall be dynamically balanced at the factory.

The shaft shall be stainless steel amply sized to carry all axial and radial thrust. The shaft shall be protected by stainless steel sleeves.

The pump rotating element shall be supported by heavy duty grease lubricated ball bearings mounted in a heavy iron housing. The bearing shall be lubricated by screw type grease cups.

2.3     Operating Characteristics

The pump shall be selected so that the operating point of specified flow and head falls near the point of maximum efficiency as obtained from the manufacturer published data. The pump shall never be selected to operate near the end of its curve.

The pump shall deliver not less than 150 percent of rated flow at a pressure not less than 65 percent of rated pressure. the shutoff pressure shall not exceed 120 percent of the rated pressure.

2.4     Pump Instrumentation

  1. a) Circulation Relief Valve

The pump shall be provided with a relief valve set below the shutoff pressure to provide circulation of sufficient water to prevent the pump from overheating when operating with no discharge. A 20mm relief valve shall be used.

Provision shall be made for a discharge to drain.

  1. b) Automatic Air release Valve

Each pump shall be provided with float operated air release valve not less than 15mm size, to automatically release air from the pump.

  1. c) Pressure Gauges

A pressure gauge shall be connected to the discharge side of the pump casing.

A compound pressure and vacuum gauge shall be connected to the suction side of pump casing with a pressure range not less than 100 psi (7 bar).

  1. Jockey Pump

A jockey pump is used to maintain the desired pressure of the fire protection system.

The pump shall be centrifugal vertical multi-stage type.

The pump casing shall be cast iron.

The pump impeller shall be stainless steel.

The shaft shall be stainless steel.

The pump shall be fitted with the following:

–        Gate valves of OS&Y indicating type on suction and discharge pipes.

–        A check valve on discharge pipe

–        One pressure gauge on pump discharge

–        One compound pressure and vacuum gauge on pump suction.

  1. Motors

The motors of all electric driven pumps shall be of squirrel cage induction type and rated for continuous operation at ambient temperature not less than 50 c.

The motors shall be totally enclosed fan cooled type with insulation class F and IP 54 protection. The motor shall be rated for 400/230 volt, 3 phase and 50 cycle. The motor shall be designed for Delta-Star Start for fire pump, and across the line start for jockey pump.

The locked rotor current of the motor shall not exceed approximately six times the full load current. The motor shall be sized so that the full load ampere rating will not be exceeded.

All motor terminals shall be marked in accordance with NEMA Standard MG1-part 2.

All motors shall be provided with nameplates in accordance with NFPA 70

The power supply feeder of the fire pumping unit shall be sized at 125 percent of the sum of the full load currents of duty fire pump, jockey pump and auxiliary loads.

Motor used at altitude above 1000 m shall be operated or derated according to NEMA standard MG1-part (14).

Motor power factor shall not be less than 0.85

The horsepower rating of the motor driving the pump shall be of such magnitude as to ensure non-overloading of the motor throughout the capacity range of the pump for the impeller size selected.

  1. Diesel Engine Drive

5.1     Engine Rating

The emergency fire pump shall be driven by a UL listed and FM approved diesel engine. The engine shall be rated at sea level and 50 C ambient temperature.

The engine horsepower rating shall be of a magnitude capable to drive the emergency pump at its maximum BHP, at altitude and ambient temperature as indicated on the drawings.

The engine speed shall not exceed 2900 rpm. The engine shall have a 4-hour minimum horsepower rating equal to or greater than the brake horsepower required to drive the pump at its rated speed under any conditions of pump load.

The engine shall be of the self-contained open type mounted on a suitable fabricated base.

5.2     Instrumentation and Control

The engine shall be provided with the following instrumentation and controls.

–        Warning light: to indicate engine running and crank termination.

–        Temperature gauge: to indicate cooling water temperature.

–        Oil pressure gauge: to indicate lubricating oil pressure.

–        Tachometer of totalizing type, to indicate rpm.

–        Hour meter: to record engine operation time.

–        Ammeter: to indicate ampere rating.

–        Speed governor: to regulate engine speed.

–        Over speed shutdown device: to shut down the engine at speed approximately 20 percent above the rated speed.

–        The engine should be equipped with ATS power supply.

All engine instruments shall be placed on a proper panel secured to the engine at a suitable location.

5.3     Engine Starting

The engine shall be equipped with a reliable device for electric starting.

Electric starting device shall take current from the storage batteries.

5.4     Storage Battery

The engine shall be provided with two storage battery units of Lead Acid Type.

Each battery unit shall have capacity, at 4.4 C, sufficient to maintain cranking speed recommended by the engine manufacturer through a 6-minute cycle (15 seconds cranking and 15 second rest in 12 consecutive cycles).

The manufacturer shall provide a certification that the battery furnished complies with this requirement.

Batteries shall be recharged by two means. One shall be the generator or alternator furnished with the engine. The other shall be automatically controlled charger taking power from an alternating current power source.

Each battery shall have battery charger listed and approved for fire pump service.

The charger shall be furnished with an ammeter to indicate the operation of charger.

The charger shall be designed so that it will not be damaged or blow fuses during the cranking cycle of the engine.

Storage batteries shall be rack supported above the floor, secured against displacement, and located where they will not be subject to excessive temperature, vibration, mechanical injury, or flooding with water. They shall be readily accessible for servicing.

5.5     Engine Cooling System

The engine cooling system shall be the closed-circuit type, including a circulating pump driven by the engine, a heat exchanger, and a reliable engine jacket temperature regulating device.

An opening shall be provided in the circuit for filling the system, checking coolant level, and adding make-up coolant when required.

The coolant shall comply with the recommendation of the engine manufacturer.

The cooling water supply for the heat exchanger shall be from the discharge of the emergency pump, taken off prior to the pump discharge valve.

The cooling water supply piping with all valves and instruments shall be arranged as shown on the drawings. Pressure regulator used in the cooling system shall be of such size and type that it is capable of and adjusted for passing approximately 120 percent of the cooling water required when the engine is operated at maximum brake horsepower, and when the fire pump is pumping 150 percent of its rated capacity at the pump pressure.

5.6     Fuel Supply System

The fuel supply system shall include fuel supply tank, piping and valves.

The fuel supply tank shall be located above ground in the pump room. The tank shall be provided with sight tube for determining the amount of fuel in the tank. The connection of fuel supply piping to the engine fuel pump shall be made by flame resistant flexible hoses approved for this service.

The fuel tank shall be provided with the required openings for the pipe connections of fuel supply, fuel return, drain, vent, fill, sight tube.

Size of fuel piping shall be according to the engine manufacturer.

Excess fuel may be returned to fuel pump suction if recommended by the engine manufacturer.

Fuel return pump shall be used if recommended by the manufacturer.

The type and grade of diesel fuel shall be as specified by the engine manufacturer.

5.7     Engine Exhaust

Exhaust from the engine shall be piped to a safe point outside the pump room. Exhausts gases shall not be discharged were they would affect persons or endanger buildings.

A seamless or welded corrugated flexible connection shall be made between the engine exhaust outlet and exhaust pipe.

The exhaust pipe size shall not be less than the engine exhaust outlet and shall be short as possible.

The exhaust piping shall be covered with high temperature insulation. The exhaust pipe shall be provided with muffler suitable for the use intended and the exhaust back pressure shall not exceed the engine manufacturer’s recommendations.

  1. Controllers and Accessories

6.1     General

All electric drive controllers shall be specifically listed for electric motor driven fire pump service and marked “Electric Fire Pump Controller”.

All engine drive controllers shall be specifically listed for diesel engine driven pump service and marked with “Diesel Engine Fire Pump Controller”.

All controllers shall be completely assembled, wired, and tested by the manufacturer before shipment from the factory.

All controllers shall indicate plainly the name of the manufacturer, the identifying designation, and the complete electrical rating.

The Contractor is fully responsible to make necessary arrangement for the services of a manufacturer’s representative for service and adjustment of the control equipment during the installation, testing and warranty periods.

All costs incurred by such services shall be on the Contractor’s own expense.

All controllers shall be so located or protected that they will not be injured by water escaping from pumps on pump connections.

All controllers shall be mounted in a proper panel enclosed in a moisture and dust tight housing.

All enclosures shall be grounded.

Busbars and other wiring elements of controllers shall be designed on a continuous duty basis.

A fire pump controller shall not be used as a junction box to supply other equipment. Electrical supply conductors for jockey pump shall not be connected to the fire pump controller, it shall have a separate controller.

All switching equipment for manual use in connecting or disconnecting, or starting, or stopping the motor shall be externally operable.

Wiring diagrams and complete instructions covering the operation of the controllers shall be provided and permanently attached to the inside of the controller enclosure.

The controllers shall be of combined automatic and manual type

Each operating component of the controller shall be labeled to indicate an identifying number referenced to the circuit diagram.

6.2     Components of Electric Drive Controller

Electric drive controllers for fire pump and jockey pump shall be provided with the following components and controls devices in accordance with NFPA 20 requirements, and shall be UL and FM.

–        Isolating switch of molded case type externally operable having an ampere rating not less than 115 percent of the motor full load current.

–        Circuit breaker for protecting the motor branch circuit of molded case time delay type having a continuous current rating not less than 115 percent of the rated full load current of the motor, and an interrupting rating equal to or greater than the available short circuit current for the circuit in which it is used.

–        Locked rotor over current protective device of time delay type having trip setting approximately six times the rated full load current of the motor.

–        Motor starter of magnetic type capable of being energized automatically through the pressure switch or manually by means of an externally operable handle.

–        Pressure-actuated switch having independent high and low calibrated adjustment in controller circuit. This pressure switch shall be responsive to water pressure in the fire protection system.

–        The pressure sensing element of the switch shall be capable of withstanding a momentary surge pressure of 27 bar without losing its accuracy.

–        The pressure sensing line shall be 15mm nominal size of copper or stainless steel suitable for the system pressure. The connection of the sensing line shall be made between the pump discharge check valve and gate valve.

–        Manual operated switch for manual starting the pump motor.

–        The pump shall remain in operation until manually shutdown.

–        Manual mechanical control to provide for non automatic continuous running operation of the motor independent of any electric control circuits.

–        Manual shutdown of automatic controller by reset push button to the controller full automatic position.

6.3     Components of diesel Engine Drive Controller

Engine drive controller shall be provided with the following components and controls devices in accordance with NFPA 20 requirements, and UL and FM.

–        Pressure-actuated switch: similar to the electric drive controller.

–        Manual operated switch for manual starting the engine. The engine shall remain in operation until manually shutdown.

–        Changeover: To provide starting current by first one battery and then the other battery on successive operations of the starter for manual and automatic starting.

–        In the event that one battery is in-operative or missing, the control shall lock-in on the remaining battery unit during the cranking sequence.

–        In the vent that the engine does not start after completion of its “attempt to start” cycle, the controller shall stop all further cranking and operate a visible indicator and audible alarm on the controller.

–        Manual shutdown by operation of main switch inside the controller enclosure.

–        Manual shutdown by operation of a stop button on the outside of the controller enclosure.

–        The controller shall shutdown the engine automatically only after all starting causes have returned to normal and a 30 minutes minimum run time has elapsed.

–        The controller shall shutdown the engine without time delay and lock out until manually reset when the engine over speed device operates.

–        The engine shall not shutdown automatically on high water temperature or low oil pressure when any starting cause exists.

6.4     Alarms and Signal Devices on Controllers

Separate visible indicators and a common audible alarm shall be provided on the controller for the following:

  1. Duty, and Jockey Pumps

–        Power available (pilot light only)

–        Power failure

–        Phase failure

–        Phase reversal

–        Pump running (automatic and manual)

–        Low water level in the water supply tank

–        Transfer switch and isolating switch positions

  1. Emergency Pump

–        Pump running (automatic and manual)

–        Low oil pressure in the lubricating system

–        High engine jacket coolant temperature

–        Failure of engine to start automatically

–        Shutdown from over speed

–        Low fuel level in the fuel tank

–        Battery failure (each battery)

–        Battery charger failure

 

 

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