Balancing In-Rack Sprinklers

[B.J. Newlin]

To balance the demand pressure with an overhead system isn't all I need is
to create a k-factor at the point the in-racks tie into the overhead system?



I have done this, but the pressure demand for the in-rack system is still 15
psi less than the pressure at that junction point for the overhead system.
Is that ok, or did I do something incorrectly?



For example 203 is the junction node. At that point the overhead system
demand is 99.09 psi with ~1450 gpm flowing.



I come up with a k factor of 145.66 (1450/sqrt of 99.09).



When I insert this K at the node and run my calcs, I end up with only 84.2
psi at node 203 for the in-racks. I assume this is acceptable since I think
I'm doing everything properly, but I can't figure out how to explain it to
the FM rep.



Any help would be appreciated. (Below is what i believe is the applicable
code text)







23.4.2.4 Hydraulic Junction Points.

23.4.2.4.1 Pressures at hydraulic junction points shall balance

within 0.5 psi (0.03 bar).

23.4.2.4.2 The highest pressure at the junction point, and

the total flows as adjusted, shall be carried into the calculations.

23.4.2.4.3 Pressure balancing shall be permitted through the

use of a K-factor developed for branch lines or portions of

systems using the formula in 23.4.2.5.

23.4.2.5 K-Factor Formula. K-factors, flow from an orifice, or

pressure from an orifice shall be determined on the basis of

the following formula:

K

Q

P n =

where:

Kn = equivalent K at a node

Q = flow at the node

P = pressure at the node



B.J. Newlin

Service Sales

Aegis Fire Protection LLC

***@aegisfirepro.com

P [phone]

F [phone]

C [phone]



"Whoever is careless with the truth in small matters cannot be trusted with
important matters"
― Albert Einstein

[R***@aerofire.com]

Sounds like you are K'ing the overhead system into the racks, if should the other way around. K the racks into the overhead system. Personally I would revisit the calc's and make them balance. A 15 psi difference is too far apart.
Ron F

-----Original Message-----
From: Sprinklerforum [mailto:sprinklerforum-***@lists.firesprinkler.org] On Behalf Of B.J. Newlin
Sent: Thursday, December 04, 2014 1:55 PM
To: ***@lists.firesprinkler.org
Subject: Balancing In-Rack Sprinklers

To balance the demand pressure with an overhead system isn't all I need is to create a k-factor at the point the in-racks tie into the overhead system?



I have done this, but the pressure demand for the in-rack system is still 15 psi less than the pressure at that junction point for the overhead system.
Is that ok, or did I do something incorrectly?



For example 203 is the junction node. At that point the overhead system demand is 99.09 psi with ~1450 gpm flowing.



I come up with a k factor of 145.66 (1450/sqrt of 99.09).



When I insert this K at the node and run my calcs, I end up with only 84.2 psi at node 203 for the in-racks. I assume this is acceptable since I think I'm doing everything properly, but I can't figure out how to explain it to the FM rep.



Any help would be appreciated. (Below is what i believe is the applicable code text)







23.4.2.4 Hydraulic Junction Points.

23.4.2.4.1 Pressures at hydraulic junction points shall balance

within 0.5 psi (0.03 bar).

23.4.2.4.2 The highest pressure at the junction point, and

the total flows as adjusted, shall be carried into the calculations.

23.4.2.4.3 Pressure balancing shall be permitted through the

use of a K-factor developed for branch lines or portions of

systems using the formula in 23.4.2.5.

23.4.2.5 K-Factor Formula. K-factors, flow from an orifice, or

pressure from an orifice shall be determined on the basis of

the following formula:

K

Q

P n =

where:

Kn = equivalent K at a node

Q = flow at the node

P = pressure at the node



B.J. Newlin

Service Sales

Aegis Fire Protection LLC

***@aegisfirepro.com

P [phone]

F [phone]

C [phone]



"Whoever is careless with the truth in small matters cannot be trusted with important matters"
― Albert Einstein

[Steve Leyton]

If you do a demand calc' for the in-racks back to the base of riser or common point of supply and it renders a lower PSI demand than the roof, you can derive a net K-factor at that point. Then, add a flowing node to the roof calc, assign it that net K-factor and it will "Q up" to the higher residual at that common point.

Steve L.




-----Original Message-----
From: Sprinklerforum [mailto:sprinklerforum-***@lists.firesprinkler.org] On Behalf Of B.J. Newlin
Sent: Thursday, December 04, 2014 12:55 PM
To: ***@lists.firesprinkler.org
Subject: Balancing In-Rack Sprinklers

To balance the demand pressure with an overhead system isn't all I need is to create a k-factor at the point the in-racks tie into the overhead system?



I have done this, but the pressure demand for the in-rack system is still 15 psi less than the pressure at that junction point for the overhead system.
Is that ok, or did I do something incorrectly?



For example 203 is the junction node. At that point the overhead system demand is 99.09 psi with ~1450 gpm flowing.



I come up with a k factor of 145.66 (1450/sqrt of 99.09).



When I insert this K at the node and run my calcs, I end up with only 84.2 psi at node 203 for the in-racks. I assume this is acceptable since I think I'm doing everything properly, but I can't figure out how to explain it to the FM rep.



Any help would be appreciated. (Below is what i believe is the applicable code text)







23.4.2.4 Hydraulic Junction Points.

23.4.2.4.1 Pressures at hydraulic junction points shall balance

within 0.5 psi (0.03 bar).

23.4.2.4.2 The highest pressure at the junction point, and

the total flows as adjusted, shall be carried into the calculations.

23.4.2.4.3 Pressure balancing shall be permitted through the

use of a K-factor developed for branch lines or portions of

systems using the formula in 23.4.2.5.

23.4.2.5 K-Factor Formula. K-factors, flow from an orifice, or

pressure from an orifice shall be determined on the basis of

the following formula:

K

Q

P n =

where:

Kn = equivalent K at a node

Q = flow at the node

P = pressure at the node



B.J. Newlin

Service Sales

Aegis Fire Protection LLC

***@aegisfirepro.com

P [phone]

F [phone]

C [phone]



"Whoever is careless with the truth in small matters cannot be trusted with important matters"
― Albert Einstein





_______________________________________________
Sprinklerforum mailing list
***@lists.firesprinkler.org
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org

[Mark A. Sornsin, P.E.]

Likewise, if that in-rack demand has a higher pressure requirement at that common point of supply, you can still use the equivalent K for the in-racks at that point. The result will just "Q up" the flow to the overhead system based on that higher pressure.

(and if the overhead system has a substantially larger minimum demand flow, it may be best to design the in-racks to a lower pressure so that when the balancing act occurs, you are 'over-flowing' the in-racks instead of the higher-volume overhead system)

(and if you want to be a REALLY annoying 'specifying engineer,' add a baseless requirement to limit velocities to 20 fps on a balancing job like this one... but I digress)

Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection Engineer | Fargo, ND | direct: 701.552.9905 | mobile: [phone] | http://www.kfiengineers.com

-----Original Message-----
From: Sprinklerforum [mailto:sprinklerforum-***@lists.firesprinkler.org] On Behalf Of Steve Leyton
Sent: Thursday, December 04, 2014 4:22 PM
To: ***@lists.firesprinkler.org
Subject: RE: Balancing In-Rack Sprinklers

If you do a demand calc' for the in-racks back to the base of riser or common point of supply and it renders a lower PSI demand than the roof, you can derive a net K-factor at that point. Then, add a flowing node to the roof calc, assign it that net K-factor and it will "Q up" to the higher residual at that common point.

Steve L.




-----Original Message-----
From: Sprinklerforum [mailto:sprinklerforum-***@lists.firesprinkler.org] On Behalf Of B.J. Newlin
Sent: Thursday, December 04, 2014 12:55 PM
To: ***@lists.firesprinkler.org
Subject: Balancing In-Rack Sprinklers

To balance the demand pressure with an overhead system isn't all I need is to create a k-factor at the point the in-racks tie into the overhead system?



I have done this, but the pressure demand for the in-rack system is still 15 psi less than the pressure at that junction point for the overhead system.
Is that ok, or did I do something incorrectly?



For example 203 is the junction node. At that point the overhead system demand is 99.09 psi with ~1450 gpm flowing.



I come up with a k factor of 145.66 (1450/sqrt of 99.09).



When I insert this K at the node and run my calcs, I end up with only 84.2 psi at node 203 for the in-racks. I assume this is acceptable since I think I'm doing everything properly, but I can't figure out how to explain it to the FM rep.



Any help would be appreciated. (Below is what i believe is the applicable code text)







23.4.2.4 Hydraulic Junction Points.

23.4.2.4.1 Pressures at hydraulic junction points shall balance

within 0.5 psi (0.03 bar).

23.4.2.4.2 The highest pressure at the junction point, and

the total flows as adjusted, shall be carried into the calculations.

23.4.2.4.3 Pressure balancing shall be permitted through the

use of a K-factor developed for branch lines or portions of

systems using the formula in 23.4.2.5.

23.4.2.5 K-Factor Formula. K-factors, flow from an orifice, or

pressure from an orifice shall be determined on the basis of

the following formula:

K

Q

P n =

where:

Kn = equivalent K at a node

Q = flow at the node

P = pressure at the node



B.J. Newlin

Service Sales

Aegis Fire Protection LLC

***@aegisfirepro.com

P [phone]

F [phone]

C [phone]



"Whoever is careless with the truth in small matters cannot be trusted with important matters"
― Albert Einstein





_______________________________________________
Sprinklerforum mailing list
***@lists.firesprinkler.org
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
_______________________________________________
Sprinklerforum mailing list
***@lists.firesprinkler.org
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please visit http://www.symanteccloud.com ______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please visit http://www.symanteccloud.com
______________________________________________________________________

[B.J. Newlin]

Thank you all for the quick replies. The overhead system is already in-place and we are simply adding the racks to their demand (Although I'd bet if we could sell upgrading the overhead system to balance the rack system, we would go that direction). The step I was missing (which Travis pointed out in his response, and Ed further explained on the phone) was to add the 99.9 psi to the K-factor to force that pressure along with the k-factor for the overhead system. It's always something simple.

Thanks for all the feedback! I learned quite a bit today, that hopefully I don't have to re-remember in another 5 years.

B.J. Newlin
Service Sales
Aegis Fire Protection LLC.

“Whoever is careless with the truth in small matters cannot be trusted with important matters”
― Albert Einstein




-----Original Message-----
From: Sprinklerforum [mailto:sprinklerforum-***@lists.firesprinkler.org] On Behalf Of Mark A. Sornsin, P.E.
Sent: Thursday, December 04, 2014 4:43 PM
To: ***@lists.firesprinkler.org
Subject: RE: Balancing In-Rack Sprinklers

Likewise, if that in-rack demand has a higher pressure requirement at that common point of supply, you can still use the equivalent K for the in-racks at that point. The result will just "Q up" the flow to the overhead system based on that higher pressure.

(and if the overhead system has a substantially larger minimum demand flow, it may be best to design the in-racks to a lower pressure so that when the balancing act occurs, you are 'over-flowing' the in-racks instead of the higher-volume overhead system)

(and if you want to be a REALLY annoying 'specifying engineer,' add a baseless requirement to limit velocities to 20 fps on a balancing job like this one... but I digress)

Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection Engineer | Fargo, ND | direct: 701.552.9905 | mobile: [phone] | http://www.kfiengineers.com

-----Original Message-----
From: Sprinklerforum [mailto:sprinklerforum-***@lists.firesprinkler.org] On Behalf Of Steve Leyton
Sent: Thursday, December 04, 2014 4:22 PM
To: ***@lists.firesprinkler.org
Subject: RE: Balancing In-Rack Sprinklers

If you do a demand calc' for the in-racks back to the base of riser or common point of supply and it renders a lower PSI demand than the roof, you can derive a net K-factor at that point. Then, add a flowing node to the roof calc, assign it that net K-factor and it will "Q up" to the higher residual at that common point.

Steve L.




-----Original Message-----
From: Sprinklerforum [mailto:sprinklerforum-***@lists.firesprinkler.org] On Behalf Of B.J. Newlin
Sent: Thursday, December 04, 2014 12:55 PM
To: ***@lists.firesprinkler.org
Subject: Balancing In-Rack Sprinklers

To balance the demand pressure with an overhead system isn't all I need is to create a k-factor at the point the in-racks tie into the overhead system?



I have done this, but the pressure demand for the in-rack system is still 15 psi less than the pressure at that junction point for the overhead system.
Is that ok, or did I do something incorrectly?



For example 203 is the junction node. At that point the overhead system demand is 99.09 psi with ~1450 gpm flowing.



I come up with a k factor of 145.66 (1450/sqrt of 99.09).



When I insert this K at the node and run my calcs, I end up with only 84.2 psi at node 203 for the in-racks. I assume this is acceptable since I think I'm doing everything properly, but I can't figure out how to explain it to the FM rep.



Any help would be appreciated. (Below is what i believe is the applicable code text)







23.4.2.4 Hydraulic Junction Points.

23.4.2.4.1 Pressures at hydraulic junction points shall balance

within 0.5 psi (0.03 bar).

23.4.2.4.2 The highest pressure at the junction point, and

the total flows as adjusted, shall be carried into the calculations.

23.4.2.4.3 Pressure balancing shall be permitted through the

use of a K-factor developed for branch lines or portions of

systems using the formula in 23.4.2.5.

23.4.2.5 K-Factor Formula. K-factors, flow from an orifice, or

pressure from an orifice shall be determined on the basis of

the following formula:

K

Q

P n =

where:

Kn = equivalent K at a node

Q = flow at the node

P = pressure at the node



B.J. Newlin

Service Sales

Aegis Fire Protection LLC

***@aegisfirepro.com

P [phone]

F [phone]

C [phone]



"Whoever is careless with the truth in small matters cannot be trusted with important matters"
― Albert Einstein





_______________________________________________
Sprinklerforum mailing list
***@lists.firesprinkler.org
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
_______________________________________________
Sprinklerforum mailing list
***@lists.firesprinkler.org
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please visit http://www.symanteccloud.com ______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please visit http://www.symanteccloud.com ______________________________________________________________________

[Todd - Work]

With a program like Autosprink, you can flow both the ceiling and in-racks simultaneously in one calc, so everything is automatically balanced.

Todd G Williams, PE
Fire Protection Design/Consulting
Stonington, CT
www.fpdc.com
860-535-2080 (ofc)

Post by B.J. Newlin
Thank you all for the quick replies. The overhead system is already in-place and we are simply adding the racks to their demand (Although I'd bet if we could sell upgrading the overhead system to balance the rack system, we would go that direction). The step I was missing (which Travis pointed out in his response, and Ed further explained on the phone) was to add the 99.9 psi to the K-factor to force that pressure along with the k-factor for the overhead system. It's always something simple.
Thanks for all the feedback! I learned quite a bit today, that hopefully I don't have to re-remember in another 5 years.
B.J. Newlin
Service Sales
Aegis Fire Protection LLC.
“Whoever is careless with the truth in small matters cannot be trusted with important matters”
― Albert Einstein
-----Original Message-----
Sent: Thursday, December 04, 2014 4:43 PM
Subject: RE: Balancing In-Rack Sprinklers
Likewise, if that in-rack demand has a higher pressure requirement at that common point of supply, you can still use the equivalent K for the in-racks at that point. The result will just "Q up" the flow to the overhead system based on that higher pressure.
(and if the overhead system has a substantially larger minimum demand flow, it may be best to design the in-racks to a lower pressure so that when the balancing act occurs, you are 'over-flowing' the in-racks instead of the higher-volume overhead system)
(and if you want to be a REALLY annoying 'specifying engineer,' add a baseless requirement to limit velocities to 20 fps on a balancing job like this one... but I digress)
Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection Engineer | Fargo, ND | direct: 701.552.9905 | mobile: [phone] | http://www.kfiengineers.com
-----Original Message-----
Sent: Thursday, December 04, 2014 4:22 PM
Subject: RE: Balancing In-Rack Sprinklers
If you do a demand calc' for the in-racks back to the base of riser or common point of supply and

[B.J. Newlin]

I've heard nothing but good things about autosprink, but that isn't a software we have.

B.J. Newlin
Service Sales
Aegis Fire Protection LLC.

“Whoever is careless with the truth in small matters cannot be trusted with important matters”
― Albert Einstein




-----Original Message-----
From: Sprinklerforum [mailto:sprinklerforum-***@lists.firesprinkler.org] On Behalf Of Todd - Work
Sent: Thursday, December 04, 2014 8:41 PM
To: ***@lists.firesprinkler.org
Subject: Re: Balancing In-Rack Sprinklers

With a program like Autosprink, you can flow both the ceiling and in-racks simultaneously in one calc, so everything is automatically balanced.

Todd G Williams, PE
Fire Protection Design/Consulting
Stonington, CT
www.fpdc.com
860-535-2080 (ofc)

Post by B.J. Newlin
Thank you all for the quick replies. The overhead system is already in-place and we are simply adding the racks to their demand (Although I'd bet if we could sell upgrading the overhead system to balance the rack system, we would go that direction). The step I was missing (which Travis pointed out in his response, and Ed further explained on the phone) was to add the 99.9 psi to the K-factor to force that pressure along with the k-factor for the overhead system. It's always something simple.
Thanks for all the feedback! I learned quite a bit today, that hopefully I don't have to re-remember in another 5 years.
B.J. Newlin
Service Sales
Aegis Fire Protection LLC.
“Whoever is careless with the truth in small matters cannot be trusted with important matters”
― Albert Einstein
-----Original Message-----
Sent: Thursday, December 04, 2014 4:43 PM
Subject: RE: Balancing In-Rack Sprinklers
Likewise, if that in-rack demand has a higher pressure requirement at that common point of supply, you can still use the equivalent K for the in-racks at that point. The result will just "Q up" the flow to the overhead system based on that higher pressure.
(and if the overhead system has a substantially larger minimum demand flow, it may be best to design the in-racks to a lower pressure so that when the balancing act occurs, you are 'over-flowing' the in-racks instead of the higher-volume overhead system)
(and if you want to be a REALLY annoying 'specifying engineer,' add a baseless requirement to limit velocities to 20 fps on a balancing job like this one... but I digress)
Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection Engineer | Fargo, ND | direct: 701.552.9905 | mobile: [phone] | http://www.kfiengineers.com
-----Original Message-----
Sent: Thursday, December 04, 2014 4:22 PM
Subject: RE: Balancing In-Rack Sprinklers
If you do a demand calc' for the in-racks back to the base of riser or common point of supply and

_______________________________________________
Sprinklerforum mailing list
***@lists.firesprinkler.org
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org

[Ben Young]

You can do the exact same balancing act with other programs as well...

Post by B.J. Newlin
I've heard nothing but good things about autosprink, but that isn't a software we have.
B.J. Newlin
Service Sales
Aegis Fire Protection LLC.
“Whoever is careless with the truth in small matters cannot be trusted
with important matters”
― Albert Einstein
-----Original Message-----
Of Todd - Work
Sent: Thursday, December 04, 2014 8:41 PM
Subject: Re: Balancing In-Rack Sprinklers
With a program like Autosprink, you can flow both the ceiling and in-racks
simultaneously in one calc, so everything is automatically balanced.
Todd G Williams, PE
Fire Protection Design/Consulting
Stonington, CT
www.fpdc.com
860-535-2080 (ofc)

Post by B.J. Newlin
Thank you all for the quick replies. The overhead system is already

in-place and we are simply adding the racks to their demand (Although I'd
bet if we could sell upgrading the overhead system to balance the rack
system, we would go that direction). The step I was missing (which Travis
pointed out in his response, and Ed further explained on the phone) was to
add the 99.9 psi to the K-factor to force that pressure along with the
k-factor for the overhead system. It's always something simple.

Post by B.J. Newlin
Thanks for all the feedback! I learned quite a bit today, that

hopefully I don't have to re-remember in another 5 years.

Post by B.J. Newlin
B.J. Newlin
Service Sales
Aegis Fire Protection LLC.
“Whoever is careless with the truth in small matters cannot be trusted

with important matters”

Post by B.J. Newlin
― Albert Einstein
-----Original Message-----

Of Mark A. Sornsin, P.E.

Post by B.J. Newlin
Sent: Thursday, December 04, 2014 4:43 PM
Subject: RE: Balancing In-Rack Sprinklers
Likewise, if that in-rack demand has a higher pressure requirement at

that common point of supply, you can still use the equivalent K for the
in-racks at that point. The result will just "Q up" the flow to the
overhead system based on that higher pressure.

Post by B.J. Newlin
(and if the overhead system has a substantially larger minimum demand

flow, it may be best to design the in-racks to a lower pressure so that
when the balancing act occurs, you are 'over-flowing' the in-racks instead
of the higher-volume overhead system)

Post by B.J. Newlin
(and if you want to be a REALLY annoying 'specifying engineer,' add a

baseless requirement to limit velocities to 20 fps on a balancing job like
this one... but I digress)

Post by B.J. Newlin
Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection

Engineer | Fargo, ND | direct: 701.552.9905 | mobile: [phone] |
http://www.kfiengineers.com

Post by B.J. Newlin
-----Original Message-----

Of Steve Leyton

Post by B.J. Newlin
Sent: Thursday, December 04, 2014 4:22 PM
Subject: RE: Balancing In-Rack Sprinklers
If you do a demand calc' for the in-racks back to the base of riser or

common point of supply and
_______________________________________________
Sprinklerforum mailing list
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
_______________________________________________
Sprinklerforum mailing list
http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org