Comparison between NFPA and TAC rules for Power plantsNFPA. TAC

NFPA 850 is standard for power stations where cross reference is made to following main

standards NFPA 13,14,15,24 and 850

TAC does not have similar code although there is a IS code for power plants which is a

recommendatory code. Following are the only standards with TAC

F P Manual, Rules for spk installations and Rules for Spray systems

City mains are accepted as an approved source of supply

City mains are not accepted

Combined fire service and general water mains are allowed

Combined fire service and general water mains are not allowed

Hydraulic calculations are must Thumb rule systems are permittedRivers are allowed as approved water source Rivers are not allowed as approved water

sourceMonitors are must in coal yards. Hydrants are permitted in coal yardsFire protection systems should be automatic in operation

Hydrant system being separate from other water based systems can also be non automatic in nature. Other systems must be automatic

When multiple fire pumps are required, pumps should not be subject to common failure. They should be of sufficient capacity to meet the demand with largest pump out of service

TAC does not require standby pumps, however, all pumps should not have the same drive.Both electrical pumps are acceptable provided supply is given from 2 independent sources like grid supply and a captive plant or DG set

Minimum pipe dia is 150mm. Velocity restriction is 3m/s.

Pipes smaller than 6 inches are permissible subject to velocity restriction of 5m/s

Elaborate requirements are given for various types of thrust blocks to be provided in pipe systems

No such details are given

No, outlets size of main hydrant valve opening and size of hydrant stand-post should be suitable for protection. Normally 2, 2 and ½ inch outlets are provided on a 6 inch standpost

Hydrants should conform to IS :5290

Authority having jurisdiction decides on spacing of hydrants no of risers required and size of pipes

Spacings are 30, 45 and 60m for High Medium and Light hazard risks. Pipe sizes and no of risers are given in the rules.

Provision of automatic fire alarm system is must This is optionalHydrant spacing in main plant area is 91.4m and in remote areas like coal yards is 152.4m. Hoses are 15or 22.5m on upper floors and 30m long on ground.Minimum Terminal pressure is 6.9 bars.

Spacing is 45m throughout. Hoses are 15m long on ground and 7.5 m on upper levels. Minimum Terminal pressure is 3.5 Bars

Hydraulic calculations are required to discharge entire flow at farthest and hydraulically remotest points considering most direct path out of service

Only half the flow is discharged at hydraulically remotest point, other half being discharged at most vulnerable point en-route

All Valves except underground valves are supervised from a central station to ensure that they are kept in open position at all times

There is no such provision

Hydrant stand posts are 150mm dia Minimum stand post dia is 80mmA valve is required on every hydrant No such requirementHydrants are located at minimum 12.2m from buildings

Minimum distance is 2m and max 15m

Steel pipes are externally coated and wrapped and internally galvanized

Internal galvanizing is not required

Working pressures are 10.3 bars Working pressures are 7,8.8 or 10.5 BarsPVC pressure pipes and chlorinated PVC threaded fittings as per schedule 80 are permitted

Plastic pipes are not allowed in ordinary and high hazard risks

Concrete pipes are allowed Concrete pipes are not allowed

Flushing of hydrant, sprinkler pipes after erection is must

There is no specific requirement

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Pipes are hydraulically pressure tested at 13.2 bars or 3.5 bars above working pressure for 2 hrs

Pipes are hydraulically tested at 150% of working pressure for 2 hours

2 hours supply water reservoir should be refilled in 8 hrs time

There is no refilling requirement

Water supply requirement for power plants is is 2 hours supply for largest Fixed fire suppression system demand plus hose stream demand of 500 GPM

Water supply requirement is 40/90 minutes supply for largest water spray system demand and hose stream demand of 1000 GPM.

Protection of following areas by appropriate fixed fire suppression systems is required to be provided

Thermal power plants.

Transformer soak pits Indoor fuel pumping and heating facilities Outdoor fuel storages Coal transfer houses Coal conveyors Coal handling Structures Underground Coal Conveyors Stacker reclaimers Boiler burner Fronts Flue gas bag type dust collectors Transformers/rectifier sets Scrubber Buildings All areas beneath the operating floor in

Turbine building Lubricating oil Tanks, Oil handling

equipments and Oil lines above the turbine floor

Turbine Generator bearings Area inside a directly connected exciter Clean and Dirty oil Storage Tanks false floors in Control Computer and

communication rooms Cable Tunnels Offices, storage rooms Warehouses containing high value

equipments and combustible materials Fire pump rooms Cooling Towers

Combined Cycle power plants

Flame and gas detectors in gas turbine enclosures

Total flooding gas or water mist or high expansion foam system in

gas turbine enclosures Appropriate systems on Exposed oil piping Turbo chargers on IC engines Lube oil reservoirs and handling

equipments Localized systems for units that are not enclosed Generator bearings Oil piping Starting equipments on combustion

turbines

This is optional. TAC does not insist on any type of protection, although they may be

desirable.

In the De-Tariff scenario Premium adjustments are done by insurers based on level of

protections achieved based on certification by accredited agencies

Pipes are laid 0.8m below ground frost level Pipes are laid 1m below groundFor upper floors Maximum travel distance is 45.7m Hose lengths on upper floors are 7.5m.

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for non sprinklered buildings and 61m for sprinklered ones. A riser is provided in each exit stairway

Maximum travel distance is 30m. it can be increased to 45m with 15m hoses

Minimum size of risers is 4 inches Minimum size of risers is 3 inchesMinimum pressures required are 6.9 bars at remotest point for class I systems and 4.5 bars for other systems

Minimum pressures required at remotest point are 3.5 bars in moderate hazard risks

Whilst considering pressure loss in risers Minimum flow rate shall be 250 GPM per riser with a maximum of 1250 GPM for non-sprinklered buildings and 1000 GPM for sprinklered ones. If sprinkler demand is more, higher of the two govern the design

Flow is taken as 125 GPM per hydrant. If sprinkler demand is more, higher of the two govern the design

For Class II and Class III systems 1and 1/2 inches hose reels are permitted in lieu of 2 and 1/2 inch hoses. 1 inch hose reels are allowed in light hazard occupancies

Only 2 and ½ inch hydrants and hose pipes are required near fire escape hydrants

No pressure regulating devises are permitted except on risers where pressures are limited to 6.9 bars on 1 and ½ inch hoses and 12.2 bars on 2 and ½ inch hoses

Orifice plates can be provided

Hydrants in remote areas can be fed by general service mains

Fire water and service water mains are always separate

Hoses conform to NFPA 1961 Hoses conform to IS 636 Hoses are kept in hose houses Hoses can be kept in hose boxes or central fire

stationsFor Risks other than power plants Supplementary hose stream demand for a combined sprinkler and hydrant system is 250 GPM for 90 minutes.

Higher of the two demands govern the pumping and reservoir capacity for a combined hydrant and sprinkler system

For Medium velocity Water spray systems, NFPA is silent on supplementary hose stream demand.

In TAC demand varies from 1150 LPM to 4500LPM for durations ranging from 40 minutes to 150 minutes for different applications

For HVWS supplementary hose demand is 1134 LPM

For HVWS supplementary hose demand is 1750 LPM.

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