Fire Protection Pumps Selection

[mechatronic]

I have to select Fire Water pumps.

NFPA is not specific on any Codes to be followed for Pumps - it says any pump with conformance to Hydraulic Institue Standards is Fine

NFPA 20 gives guidelines is only for Installation.

API models are not required since this is not a Oil/ Gas area

Please help me what standard should I refer

Pumps sizes are

1. 95 Liters per Second

2. 160 Liters per Second
3. 7 liters per Second

All to deliver at 8.8 Kg gauge

Can I select ANSI models what should be the approach

 

[Zapster]

What is kg gauge?

I have heard of pumps output given as Flow (mass/time or volume/time) at a given pressure (force/length^2 or length).

 

[Artisi]

If the pumps don't need to meeet the NFPA Standard for pumps / motor / engines and controllers, you are free to choose what ever type, model or manufacturer that you like.
However, if you are not capable or don't have the experience to make an informed selection on what to use, a good approach is to look at what pumps /motors / engines / controllers that meet the std. and select the same equipment or ask a supplying who is experienced in fire pump supply.

Naresuan University
Phitsanulok
Thailand

 

[bulkhandling]

Your pump layout may be one of the considerations. If you hae a large reservior and you like to put pump above it but deep enough to get minimum water reserve, you may prefer a vertical type pump such as vertical turbine pump (or pumps).

Head: or pressure. You require a minimum permanent pressure in the piping. The pump or pumps shall be easy to start. pressure is alway higher than a single stage pump, you need multistage pump if centrifugal is the choice.

So multistage vertical turbine Jockey pumps are normally our selections. Such pump has a good curve with wide volume range and wide pressure range, meaning if water consumption is high (pressure is low), pump can supply that demand.

 

[mk3223]

NFPA 20 is the standard for the fire pump design and manufacture. it has some requirements different from API and ANSI pump and special control instrument needed for operation. And, it is UL listed pump.
If agreed with the local fire authority, you may use non-NFPA pump for the firewater system.

 

[LCREP]

"If agreed with the local fire authority, you may use non-NFPA pump for the firewater system"


Before you do the above better check with the insurance carrier. If the pump is not an UL listed or FM approved fire pump we would give no credit for the water supply and sprinkler protection. Which means you would pay a lot more $$$ for insurance for the life of the pump.

 

[mk3223]

LCREP has a good point for it. Thanks.

 

[Harold53]

mechatronic
Firefighting pumps should be UL Listed and Factory Mutual approved to avoid troubbles with your insurance company.
Regarding your specific requirements, FF pumps are rated on the basis of 250 gpm per hose. So you have :

95 L/s = 1500 gpm
160 L/s = 2500 gpm

However, your 7 L/s (125 gpm) seems to be low but may be you need it for a sprinkler or tank roof cooling system.

Your rating for 8.8 kg must refer to 8.8 kg/cm2 and if it is your pressure, it seems a little bit high because the firefighting systems works normally about 7 kg/cm2, but of course it depends on your specifical piping arrangement.

The main concern about selecting a fire fighting pump is that the pump curve must be almost flat around its selection point to meet the minimum requirement to supply 150% of its nominal flow with a lowering in its head of just 35% and a shutoff head no higher than 120% of its operating head.

Additionally You must take care to check the water supply and the motor spec. You may need a diesel engine speccially provided and listed to this application. You need also a jockey pump , joints and valves FM / UL Listed, so the stuff seems a little heavy to take this as your first experience.

Because of the significance of such a system, you should contact at least a local ff pumps provider such as Peerless, Flowserve-Dresser-Worthington, Allis Chalmers and maybe you can get more clarity.

Regards,

harold53

 

[sharique]

Useful replies undoubtedly!
I would like to add the following....
- Selection of the pump shall be based on the design requirements of the system. Selection should be backed by hydraulic analysis of the system. Like how much flow at what pressure requires to be maintained at the extreme end of fire protection system (sprinkler or hydrants).
- The selection of pumps could be based on the water resources. Whether it’s a below ground water tank or above ground, where the pumps needs to be installed etc.
- There is no such selection basis specified in NFPA 20. This standard mainly deals with the installation requirements of centrifugal single-stage and multistage pumps of horizontal or vertical shaft design and positive displacement pumps of the horizontal or vertical shaft design.
- Generally local authorities (safety/security/civil defense) asks for UL/FM approved Pumps & systems components.

Sharique