Water Pump Meeting both NFPA20 and NSF61

[kc27315]

Suppose I'm designing a single service main to serve BOTH fire sprinkler/hydrants AND domestic needs. I would love for the pump gods to have come up with a way to create a single high flow pump that is fire rated (NFPA 20) AND meets drinking water standards (NSF 61). Is anyone aware of a pump manufacturer that has come up with a way to do this?

 

[BSMEclassof2012]

kc27315:​

Is this question for a general curiosity or for an actual project? If it is for a project, do you have a completed datasheet covering all details including flow requirement, product viscosity, temperature, pressure and the factors? The pump material will obviously depend on these variable. What margin was used on pump flowrate (an important feature)? In the datasheet, mention the requirement of NFPA 20 and NSF 61 standards. Once you have that, you can contact the pump manufacturers like Flowserve, Sulzer and others with your request. They may or may not offer you an out of shelf pump or they will provide you a pump that is custom made. I hope this helps. good luck!

 

[LittleInch]

I doubt anyone will sign this off.

There are somethings which just don't mix and this is one of them.

FW systems work to there own standards and systems and that includes manufacturing, installation, testing and performance.

Just not worth going there.

 

[kc27315]

Thanks so much for your reply. It is regarding an actual project, but I don't have a completed datasheet. I have spoken with several manufacturers, and they've all suggested that there does not exist a pump which meets both NFPA 20 and NSF 61. I think they've suggested something like gaskets used (I might be wrong on the particular detail) on fire pumps (NFPA 20) contain lead, and therefore don't meet drinking water (NSF 61) standards. I'm hoping someone (anyone) is able to confirm whether they are aware of even a single example (even if it's custom made) of a pump that a designer has used to meet both of those criteria. Even if it happens to be different than the viscosity/temperature/etc than my particular project.

I don't want to waste too much time looking for something if no one has ever been successful in coming up with a pump that meets both NFPA and NSF.

 

[kc27315]

I doubt anyone will sign this off.

There are somethings which just don't mix and this is one of them.

FW systems work to there own standards and systems and that includes manufacturing, installation, testing and performance.

Just not worth going there.

LittleInch,

Thank you for your input. All the manufacturer's I've spoken with have said the same thing as you and this is what I am afraid of. It just seems that someone could become a millionaire pretty quick if they found a way to make such a pump feasible/possible. My particular project has a large water system with a single connection to the City, followed by the pump house, followed by a single huge loop. It would be a huge cost savings to be able to combine the fire and domestic flows in the same loop, rather than have to create a second huge loop - have one loop for fire and the other for domestic. I've got to believe that there are hundreds of projects that could benefit from such a miraculous unicorn of a pump.

 

[LittleInch]

There are many fire systems which run off the domestic system - think any "normal" fire hydrant.

NFPA systems are normally for industrial locations and I'm sure there are relevant NFPA standards dealing with domestic sprinkler systems.

It all depends on the fire water flow rates compared to normal flow. Most of the time you only reckon on one building catching fire or whatever your local AHJ specifies.

You need to understand why someone wants an NFPA fire pump.

 

[kc27315]

There are many fire systems which run off the domestic system - think any "normal" fire hydrant.

NFPA systems are normally for industrial locations and I'm sure there are relevant NFPA standards dealing with domestic sprinkler systems.

It all depends on the fire water flow rates compared to normal flow. Most of the time you only reckon on one building catching fire or whatever your local AHJ specifies.

You need to understand why someone wants an NFPA fire pump.

What's interesting in my case is that everyone (City, Fire Marshall, etc) signed off the plans which included a drinking water rated NSF 61 pump to serve domestic, hydrants, and risers/sprinklers in parallel with a few smaller pumps to serve everyday use. Turns out that the only "someone" who wanted (required) the pump to be NFPA 20 on this project was the insurance company the owner decided to switch over to .
And, yes, we were modeling/designing, we were instructed to assume each building on fire independently of the others.

I really do appreciate your input on this, so thank you.

 

[Artisi]

The insurance underwriter, the "someone* as you called them are the authority when it comes to the fire pump spec. As it's their risk, they dictate what's acceptable.

 

[kc27315]

The insurance underwriter, the "someone* as you called them are the authority when it comes to the fire pump spec. As it's their risk, they dictate what's acceptable.

I can't argue with that.

 

[Artisi]

That's entirely upto you, but see how you go getting the insurance policy if the fire pump is not acceptable to them.

 

[kc27315]

That's entirely upto you, but see how you go getting the insurance policy if the fire pump is not acceptable

If the pump isnt acceptable, then, of course it's not possible to get a policy. It would sure be convenient if some einstein-level manufactuter came up with a magical pump that would be both acceptable to an insurance company AND meet drinking water standards.

 

[Artisi]

The problem is a fire pump is always on stand -by, once a pressure drop is registered it will come online, so how can it also be used as a water supply pump?

 

[kc27315]

The problem is a fire pump is always on stand -by, once a pressure drop is registered it will come online, so how can it also be used as a water supply pump?

It's not used as a domestic water supply pump, but is connected to the single main that supplies domestic and fire suppression needs. So if it is NFPA 20 rated, then it could contaminate the drinking water if it were ever used.

 

[pierreick]

Hi,
To my knowledge the discharge pressure of a fire pump is about 12 bars! BTW you should have also jokey pumps to maintain the pressure within the system.
Nothing to do with domestic supply.
Again, check with the insurance broker in charge of your facility and the fire brigade.
To me, this is a NO!

Pierre

 

[Artisi]

Hi,
To my knowledge the discharge pressure of a fire pump is about 12 bars! BTW you should have also jokey pumps to maintain the pressure within the system.
Nothing to do with domestic supply.
Again, check with the insurance broker in charge of your facility and the fire brigade.
To me, this is a NO!

Pierre

NO is correct, you can't have a combined mixed fire pump / domestic supply, from the same main supply maybe possible but again depends on the fire code / insurance underwriter, a major fire system could even require a separate stored source.

 

[TenPenny]

There is a thread ON HERE about this topic:

NFPA 20 - Dedication of Fire Pumps - NFPA (fire) Code Issues

Hi Guys, I went through NFPA 20 - regarding the possibility of using the fire pump for other purposes. example: Use fire pump to flush the fire system piping network, but couldn't find any reference about this subject. please advise if you have any information related to this point. Note: I...

www.eng-tips.com

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Note: I found this paragraph from NFPA 20 - 2016 Edition, but no restrictions!!!
4.7 Pumps, Drivers, and Controllers.
4.7.1* Fire pumps shall be dedicated to and listed for fire protection service."