RE: Multiple Pumps

[Cahill, Christopher]

You should try an Air Force hangar with a foam inductor at 35% loss, 20 psi for 
the flow control valve/prv, 40 psi end head pressure on the foam generators, 
100' in the air, pulling water from a tank.  You're at 150 psi before you put 
any pipe in.  Then you have to use small pipe to get decent velocity in the 
pipe to cover the plane silhouette in 60 seconds in a 400' x 200' bay.  This 
isn't the highest pressure we've used.  I think our highest churn is 330 psi on 
another project and we only added a 100 psi pump.  A lot of extenuating 
circumstances on that one.  High static, low residual at flow, pumps in series, 
existing conditions, no money or room from a break tanks, so on and so forth. 
Good times all around.

Chris Cahill, PE*
Associate Fire Protection Engineer
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
ccah...@burnsmcd.com<mailto:ccah...@burnsmcd.com>
www.burnsmcd.com<http://www.burnsmcd.com/>
*Registered in: MN

If Americans switched from pounds to kilograms there would be mass confusion.

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Prahl, Craig/GVL
Sent: Wednesday, December 20, 2017 10:31 AM
To: sprinklerforum@lists.firesprinkler.org
Subject: RE: Multiple Pumps

At 215 psi?  Why the high pressure rating?  Are you specifying high pressure 
components on the systems?  Relief valves


Craig L. Prahl
Fire Protection Group Lead/SME
JACOBS - CH2M
200 Verdae Blvd.
Greenville, SC  29607
Direct - 864.920.7540
Fax - 864.920.7129
CH2MHILL Extension  77540
craig.pr...@ch2m.com<mailto:craig.pr...@ch2m.com>


From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Cahill, Christopher
Sent: Wednesday, December 20, 2017 11:23 AM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: RE: Multiple Pumps [EXTERNAL]

Appreciate the input folks.  To my surprise got a response from NFPA faster 
than expected.

"There is nothing in NFPA 20 that prohibits the use of multiple pumps in 
parallel. Section 4.9.1 is simply saying that the demand cannot exceed 150 
percent of the rated capacity of a single pump - this does not mean that you 
can't use multiple pumps to meet the system demand."

We're talking about 3 - 1,500's at 215 psi.  One is redundant. In consultation 
with contractors they thought 3 would be better and cheaper than 2 - 2500's at 
215 psi due to long lead time and cost of those not so readily available motors 
for the bigger pumps.  Also, provides better pressure curve being the demand is 
around 2,500.  I agree this isn't typical situation.  Well I'm about to do it 
again soon, so is 3 times in two years typical?

Chris Cahill, PE*
Associate Fire Protection Engineer
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
ccah...@burnsmcd.com<mailto:ccah...@burnsmcd.com>
www.burnsmcd.com<http://www.burnsmcd.com/>
*Registered in: MN

If Americans switched from pounds to kilograms there would be mass confusion.

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Matt Grise
Sent: Wednesday, December 20, 2017 9:04 AM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: RE: Multiple Pumps

It seems like this would also introduce more moving parts/valves/etc that would 
require maintenance and possibly fail.

Matt

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Prahl, Craig/GVL
Sent: Wednesday, December 20, 2017 7:34 AM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: RE: Multiple Pumps

You could use multiple pumps to achieve the desired flow rate but there would 
be no advantage in doing so.  You would ultimately cost the owner more money in 
up-front installation costs as well as long term maintenance and inspection 
costs.

I do a lot of large flow facilities where 8,000 -12,000 gpm flow rates are not 
unusual.  You can only achieve those rates with multiple pumps.  Typically, 
those are high risk facilities and there is always one extra pump that acts as 
a reserve in case one would be out of service.  Sometimes we may use a smaller 
pump (500-1000 gpm) that better reflects the majority of the site's  sprinkler 
demand and make that the primary with the others coming on-line for a large 
flow event like fire flow or a deluge system.

If I had extreme variable flow conditions there are Variable Speed Drives for 
electric fire pumps. There is no need to try and "throttle" the flow by using 
multiple small pumps.

So basically, just because you can, doesn't mean you should.

Craig L. Prahl
Fire Protection Group Lead/SME
JACOBS - CH2M
200 Verdae Blvd.
Greenville, SC  29607
Direct - 864.920.7540
Fax - 864.920.7129
CH2MHILL Extension  77540
craig.pr...@ch2m.com<mailto:craig.pr...@ch2m.com>

From:

RE: Multiple Pumps

[Prahl, Craig/GVL]

At 215 psi?  Why the high pressure rating?  Are you specifying high pressure 
components on the systems?  Relief valves


Craig L. Prahl
Fire Protection Group Lead/SME
JACOBS - CH2M
200 Verdae Blvd.
Greenville, SC  29607
Direct - 864.920.7540
Fax - 864.920.7129
CH2MHILL Extension  77540
craig.pr...@ch2m.com


From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Cahill, Christopher
Sent: Wednesday, December 20, 2017 11:23 AM
To: sprinklerforum@lists.firesprinkler.org
Subject: RE: Multiple Pumps [EXTERNAL]

Appreciate the input folks.  To my surprise got a response from NFPA faster 
than expected.

"There is nothing in NFPA 20 that prohibits the use of multiple pumps in 
parallel. Section 4.9.1 is simply saying that the demand cannot exceed 150 
percent of the rated capacity of a single pump - this does not mean that you 
can't use multiple pumps to meet the system demand."

We're talking about 3 - 1,500's at 215 psi.  One is redundant. In consultation 
with contractors they thought 3 would be better and cheaper than 2 - 2500's at 
215 psi due to long lead time and cost of those not so readily available motors 
for the bigger pumps.  Also, provides better pressure curve being the demand is 
around 2,500.  I agree this isn't typical situation.  Well I'm about to do it 
again soon, so is 3 times in two years typical?

Chris Cahill, PE*
Associate Fire Protection Engineer
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
ccah...@burnsmcd.com<mailto:ccah...@burnsmcd.com>
www.burnsmcd.com<http://www.burnsmcd.com/>
*Registered in: MN

If Americans switched from pounds to kilograms there would be mass confusion.

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Matt Grise
Sent: Wednesday, December 20, 2017 9:04 AM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: RE: Multiple Pumps

It seems like this would also introduce more moving parts/valves/etc that would 
require maintenance and possibly fail.

Matt

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Prahl, Craig/GVL
Sent: Wednesday, December 20, 2017 7:34 AM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: RE: Multiple Pumps

You could use multiple pumps to achieve the desired flow rate but there would 
be no advantage in doing so.  You would ultimately cost the owner more money in 
up-front installation costs as well as long term maintenance and inspection 
costs.

I do a lot of large flow facilities where 8,000 -12,000 gpm flow rates are not 
unusual.  You can only achieve those rates with multiple pumps.  Typically, 
those are high risk facilities and there is always one extra pump that acts as 
a reserve in case one would be out of service.  Sometimes we may use a smaller 
pump (500-1000 gpm) that better reflects the majority of the site's  sprinkler 
demand and make that the primary with the others coming on-line for a large 
flow event like fire flow or a deluge system.

If I had extreme variable flow conditions there are Variable Speed Drives for 
electric fire pumps. There is no need to try and "throttle" the flow by using 
multiple small pumps.

So basically, just because you can, doesn't mean you should.

Craig L. Prahl
Fire Protection Group Lead/SME
JACOBS - CH2M
200 Verdae Blvd.
Greenville, SC  29607
Direct - 864.920.7540
Fax - 864.920.7129
CH2MHILL Extension  77540
craig.pr...@ch2m.com<mailto:craig.pr...@ch2m.com>

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Cahill, Christopher
Sent: Tuesday, December 19, 2017 6:05 PM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: Multiple Pumps [EXTERNAL]

So I found this in NFPA 20 - 4.9.1 A centrifugal fire pump for fire protection 
shall be selected so that the greatest single demand for any fire protection 
system connected to the pump is less than or equal to 150 percent of the rated 
capacity (flow) of the pump.

So does that mean if the demand is 1,000 gpm I can't use 3 - 250 gpm pumps?  
Don't ask why someone would do that, yes it would be odd.  Think really big 
flows and high pressures where variable flow in reality one might choose to 
split the pumps.

So basically isn't it demanding a single pump for systems up to 7,500 gpm? 
(assuming a 5,000 gpm pump is the maximum) No option for using 2 - 3,000's?

Chris Cahill, PE*
Associate Fire Protection Engineer
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
ccah...@burnsmcd.com<mailto:ccah...@burnsmcd.com>
www.burnsmcd.com<http://www.burnsmcd.com/>
*Registered in: MN

If Americans switched from pounds to kilograms there would be mass confusion.

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Sprink

RE: Multiple Pumps

[Cahill, Christopher]

Appreciate the input folks.  To my surprise got a response from NFPA faster 
than expected.

"There is nothing in NFPA 20 that prohibits the use of multiple pumps in 
parallel. Section 4.9.1 is simply saying that the demand cannot exceed 150 
percent of the rated capacity of a single pump - this does not mean that you 
can't use multiple pumps to meet the system demand."

We're talking about 3 - 1,500's at 215 psi.  One is redundant. In consultation 
with contractors they thought 3 would be better and cheaper than 2 - 2500's at 
215 psi due to long lead time and cost of those not so readily available motors 
for the bigger pumps.  Also, provides better pressure curve being the demand is 
around 2,500.  I agree this isn't typical situation.  Well I'm about to do it 
again soon, so is 3 times in two years typical?

Chris Cahill, PE*
Associate Fire Protection Engineer
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
ccah...@burnsmcd.com<mailto:ccah...@burnsmcd.com>
www.burnsmcd.com<http://www.burnsmcd.com/>
*Registered in: MN

If Americans switched from pounds to kilograms there would be mass confusion.

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Matt Grise
Sent: Wednesday, December 20, 2017 9:04 AM
To: sprinklerforum@lists.firesprinkler.org
Subject: RE: Multiple Pumps

It seems like this would also introduce more moving parts/valves/etc that would 
require maintenance and possibly fail.

Matt

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Prahl, Craig/GVL
Sent: Wednesday, December 20, 2017 7:34 AM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: RE: Multiple Pumps

You could use multiple pumps to achieve the desired flow rate but there would 
be no advantage in doing so.  You would ultimately cost the owner more money in 
up-front installation costs as well as long term maintenance and inspection 
costs.

I do a lot of large flow facilities where 8,000 -12,000 gpm flow rates are not 
unusual.  You can only achieve those rates with multiple pumps.  Typically, 
those are high risk facilities and there is always one extra pump that acts as 
a reserve in case one would be out of service.  Sometimes we may use a smaller 
pump (500-1000 gpm) that better reflects the majority of the site's  sprinkler 
demand and make that the primary with the others coming on-line for a large 
flow event like fire flow or a deluge system.

If I had extreme variable flow conditions there are Variable Speed Drives for 
electric fire pumps. There is no need to try and "throttle" the flow by using 
multiple small pumps.

So basically, just because you can, doesn't mean you should.

Craig L. Prahl
Fire Protection Group Lead/SME
JACOBS - CH2M
200 Verdae Blvd.
Greenville, SC  29607
Direct - 864.920.7540
Fax - 864.920.7129
CH2MHILL Extension  77540
craig.pr...@ch2m.com<mailto:craig.pr...@ch2m.com>

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Cahill, Christopher
Sent: Tuesday, December 19, 2017 6:05 PM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: Multiple Pumps [EXTERNAL]

So I found this in NFPA 20 - 4.9.1 A centrifugal fire pump for fire protection 
shall be selected so that the greatest single demand for any fire protection 
system connected to the pump is less than or equal to 150 percent of the rated 
capacity (flow) of the pump.

So does that mean if the demand is 1,000 gpm I can't use 3 - 250 gpm pumps?  
Don't ask why someone would do that, yes it would be odd.  Think really big 
flows and high pressures where variable flow in reality one might choose to 
split the pumps.

So basically isn't it demanding a single pump for systems up to 7,500 gpm? 
(assuming a 5,000 gpm pump is the maximum) No option for using 2 - 3,000's?

Chris Cahill, PE*
Associate Fire Protection Engineer
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
ccah...@burnsmcd.com<mailto:ccah...@burnsmcd.com>
www.burnsmcd.com<http://www.burnsmcd.com/>
*Registered in: MN

If Americans switched from pounds to kilograms there would be mass confusion.

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RE: Multiple Pumps

[Matt Grise]

It seems like this would also introduce more moving parts/valves/etc that would 
require maintenance and possibly fail.

Matt

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Prahl, Craig/GVL
Sent: Wednesday, December 20, 2017 7:34 AM
To: sprinklerforum@lists.firesprinkler.org
Subject: RE: Multiple Pumps

You could use multiple pumps to achieve the desired flow rate but there would 
be no advantage in doing so.  You would ultimately cost the owner more money in 
up-front installation costs as well as long term maintenance and inspection 
costs.

I do a lot of large flow facilities where 8,000 -12,000 gpm flow rates are not 
unusual.  You can only achieve those rates with multiple pumps.  Typically, 
those are high risk facilities and there is always one extra pump that acts as 
a reserve in case one would be out of service.  Sometimes we may use a smaller 
pump (500-1000 gpm) that better reflects the majority of the site's  sprinkler 
demand and make that the primary with the others coming on-line for a large 
flow event like fire flow or a deluge system.

If I had extreme variable flow conditions there are Variable Speed Drives for 
electric fire pumps. There is no need to try and "throttle" the flow by using 
multiple small pumps.

So basically, just because you can, doesn't mean you should.

Craig L. Prahl
Fire Protection Group Lead/SME
JACOBS - CH2M
200 Verdae Blvd.
Greenville, SC  29607
Direct - 864.920.7540
Fax - 864.920.7129
CH2MHILL Extension  77540
craig.pr...@ch2m.com<mailto:craig.pr...@ch2m.com>


From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Cahill, Christopher
Sent: Tuesday, December 19, 2017 6:05 PM
To: 
sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>
Subject: Multiple Pumps [EXTERNAL]

So I found this in NFPA 20 - 4.9.1 A centrifugal fire pump for fire protection 
shall be selected so that the greatest single demand for any fire protection 
system connected to the pump is less than or equal to 150 percent of the rated 
capacity (flow) of the pump.

So does that mean if the demand is 1,000 gpm I can't use 3 - 250 gpm pumps?  
Don't ask why someone would do that, yes it would be odd.  Think really big 
flows and high pressures where variable flow in reality one might choose to 
split the pumps.

So basically isn't it demanding a single pump for systems up to 7,500 gpm? 
(assuming a 5,000 gpm pump is the maximum) No option for using 2 - 3,000's?

Chris Cahill, PE*
Associate Fire Protection Engineer
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
ccah...@burnsmcd.com<mailto:ccah...@burnsmcd.com>
www.burnsmcd.com<http://www.burnsmcd.com/>
*Registered in: MN

If Americans switched from pounds to kilograms there would be mass confusion.

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RE: Multiple Pumps

[Prahl, Craig/GVL]

You could use multiple pumps to achieve the desired flow rate but there would 
be no advantage in doing so.  You would ultimately cost the owner more money in 
up-front installation costs as well as long term maintenance and inspection 
costs.

I do a lot of large flow facilities where 8,000 -12,000 gpm flow rates are not 
unusual.  You can only achieve those rates with multiple pumps.  Typically, 
those are high risk facilities and there is always one extra pump that acts as 
a reserve in case one would be out of service.  Sometimes we may use a smaller 
pump (500-1000 gpm) that better reflects the majority of the site's  sprinkler 
demand and make that the primary with the others coming on-line for a large 
flow event like fire flow or a deluge system.

If I had extreme variable flow conditions there are Variable Speed Drives for 
electric fire pumps. There is no need to try and "throttle" the flow by using 
multiple small pumps.

So basically, just because you can, doesn't mean you should.

Craig L. Prahl
Fire Protection Group Lead/SME
JACOBS - CH2M
200 Verdae Blvd.
Greenville, SC  29607
Direct - 864.920.7540
Fax - 864.920.7129
CH2MHILL Extension  77540
craig.pr...@ch2m.com


From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On 
Behalf Of Cahill, Christopher
Sent: Tuesday, December 19, 2017 6:05 PM
To: sprinklerforum@lists.firesprinkler.org
Subject: Multiple Pumps [EXTERNAL]

So I found this in NFPA 20 - 4.9.1 A centrifugal fire pump for fire protection 
shall be selected so that the greatest single demand for any fire protection 
system connected to the pump is less than or equal to 150 percent of the rated 
capacity (flow) of the pump.

So does that mean if the demand is 1,000 gpm I can't use 3 - 250 gpm pumps?  
Don't ask why someone would do that, yes it would be odd.  Think really big 
flows and high pressures where variable flow in reality one might choose to 
split the pumps.

So basically isn't it demanding a single pump for systems up to 7,500 gpm? 
(assuming a 5,000 gpm pump is the maximum) No option for using 2 - 3,000's?

Chris Cahill, PE*
Associate Fire Protection Engineer
Burns & McDonnell
Phone:  952.656.3652
Fax:  952.229.2923
ccah...@burnsmcd.com
www.burnsmcd.com
*Registered in: MN

If Americans switched from pounds to kilograms there would be mass confusion.

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Re: Multiple Pumps

[Bruce Verhei]

Chris,

I’m used to seeing an electric and a diesel driven pump, each sized to support 
sprinkler system design criteria. But I think these came out the old FM or IRI 
HPR programs. And it is not unusual where in effect a fire sprinkler supply 
utility is created within a business park. 

The refinery and hydrocarbon platforms have monstrous flow numbers. They use 
several pumps to provide flows.

Best.

Bruce Verhei 

> On Dec 19, 2017, at 15:05, Cahill, Christopher  wrote:
> 
> So I found this in NFPA 20 - 4.9.1 A centrifugal fire pump for fire 
> protection shall be selected so that the greatest single demand for any fire 
> protection system connected to the pump is less than or equal to 150 percent 
> of the rated capacity (flow) of the pump.
>  
> So does that mean if the demand is 1,000 gpm I can’t use 3 - 250 gpm pumps?  
> Don’t ask why someone would do that, yes it would be odd.  Think really big 
> flows and high pressures where variable flow in reality one might choose to 
> split the pumps. 
>  
> So basically isn’t it demanding a single pump for systems up to 7,500 gpm? 
> (assuming a 5,000 gpm pump is the maximum) No option for using 2 - 3,000’s?
>  
> Chris Cahill, PE*
> Associate Fire Protection Engineer
> Burns & McDonnell
> Phone:  952.656.3652
> Fax:  952.229.2923
> ccah...@burnsmcd.com
> www.burnsmcd.com
> *Registered in: MN
>  
> If Americans switched from pounds to kilograms there would be mass confusion. 
>  
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RE: Multiple Pumps

[Tom Duross]

The only time I saw this was to keep system pressure down, limit churn to 3
500's instead of a 1500.  

TD

 

From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org]
On Behalf Of Cahill, Christopher
Sent: Tuesday, December 19, 2017 6:05 PM
To: sprinklerforum@lists.firesprinkler.org
Subject: Multiple Pumps

 

So I found this in NFPA 20 - 4.9.1 A centrifugal fire pump for fire
protection shall be selected so that the greatest single demand for any fire
protection system connected to the pump is less than or equal to 150 percent
of the rated capacity (flow) of the pump.

 

So does that mean if the demand is 1,000 gpm I can't use 3 - 250 gpm pumps?
Don't ask why someone would do that, yes it would be odd.  Think really big
flows and high pressures where variable flow in reality one might choose to
split the pumps.  

 

So basically isn't it demanding a single pump for systems up to 7,500 gpm?
(assuming a 5,000 gpm pump is the maximum) No option for using 2 - 3,000's?

 

Chris Cahill, PE*

Associate Fire Protection Engineer 

Burns & McDonnell

Phone:  952.656.3652

Fax:  952.229.2923

  ccah...@burnsmcd.com

  www.burnsmcd.com

*Registered in: MN

 

If Americans switched from pounds to kilograms there would be mass
confusion. 

 

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