NFPA 25 HBK - Comments on dry system water delivery to IT. What?

[ContractorDave]

Frequently when reading code I'll come across a piece that's hard to digest and I'll decide to ask this good forum for an opinion. Sometimes while writing it down here it will suddenly become clear and I won't have to post it. Other times I will post it and get some valuable information. Here's something out of the NFPA 25 handbook that has me puzzled. This is from the comment section of 13.2.6.1. Although it's about the mechanical waterflow devices, it speaks to the water delivery times of dry systems:

"Dry pipe systems with a capacity of 500 gal (1893 L) or less, and dry systems with a capacity between 500 gal (1893 L) and 750 gal (2839 L) with a quick opening device installed, do not have to meet any specific water delivery requirement. While there is no time limit for water delivery for these systems, the test is considered successful when water flows at the inspector's test connection.

Systems with a capacity of greater than 750 gal (2839 L) or greater than 500 gal (1893 L) without a quick opening device must deliver water in 60 seconds. In addition, dry pipe system trip times are allowed to be calculated by NFPA 13 starting with its 2007 edition."

The first paragraph informs us that there is no specific water delivery requirement (time) for the specified systems. The second paragraph states that the larger 750+ gallon systems, or those greater than 500 gal without a QOD must meet the 60 second rule. Is it presumed that the systems identified in the 1st paragraph will naturally meet the 60 second rule then? If so, why isn't it simply stated that all of these systems must meet the rule?

Regards
D

A thing moderately good is not so good as it ought to be
Thomas Paine

http://www.ykfireprevention.ca

 

[SprinklerDesigner2]

Actually all dry pipe systems with a capacity > 500 gpm have been required to have a QOD for a long time now.

The only place where 60 second trip times are mentioned anywhere is the exception where systems are greater than 750 gallons but watch for the amendments to your local codes.

 

[cdafd]

Is it presumed that the systems identified in the 1st paragraph will naturally meet the 60 second rule then?""

I do not think the code requires it.


also, using certain fire sprinklers, a system has to meet the 60 seconds no matter what size

 

[SprinklerDesigner2]

cdafd,

Going strictly by 13 it doesn't matter if the system is < 500 gallons or < 750 gallons with a QOD. I am going by memory here but I don't think a QOD is required if the system > 500 gallons and water gets to the inspectors test in 60 seconds.

7.2.3* Size of Systems — Volume Limitations.
7.2.3.1* Unless the requirements of 7.2.3.2 or 7.2.3.3 are met, not more than 750 gal (2839 L) system capacity shall be controlled by one dry pipe valve.
7.2.3.2 Piping volume shall be permitted to exceed the requirements of 7.2.3.1 where the system design is such that water is delivered to the system test connection in not more than 60 seconds, starting at the normal air pressure on the system and at the time of fully opened inspection test connection.

7.2.3.2 is the only place 60 seconds is mentioned as a requirement.

Two things, that is 2002 which I am still trapped in and be well aware of any adopted fire codes your jurisdiction may have. I remember back in the 80's Ohio was operating under BOCA and the BOCA fire code required 60 seconds regardless of system size.

 

[ContractorDave]

NFPA 25 A.13.4.4.2.2.2 (2011 ed)in regards to dry valve test procedures, item (5):
"Testers at the inspector's test note the time at which water flows steadily from the test connection. This time is noted for comparison purposes to previous tests and is not meant to be a specific pass/fail criterion. Note that NFPA 13, Standard for the Installation of Sprinkler Systems, does not require water delivery in 60 seconds for all systems."

So when doing inspections, the only apparent concern is if you get water at all. An inspector is not required to verify the system has been installed correctly, and unless the O&M manual is available with the original Contractors M&TC, the only data one might have is from previous inspection reports.



Regards
D

A thing moderately good is not so good as it ought to be
Thomas Paine

http://www.ykfireprevention.ca

 

[cdafd]

have to love nfpa 25

so sounds like it says that no matter the original system install had to meet 60 seconds, unless there is documentation saying so, during the nfpa 25 inspection it can go over????

 

[SprinklerDesigner2]

Yep.

Three minutes and forty seconds? No problemo as far as the standards are concerned.

 

[ContractorDave]

For clarity, and yes I jest, item (9) of the same section adds this:
"The system is not required to achieve water delivery to the inspector’s test
connection in 60 seconds, but comparison to the water delivery time during the
original acceptance will determine if there is a problem with the system."

This seems like a committee trying very hard not to commit. As it were...

Regards
D

A thing moderately good is not so good as it ought to be
Thomas Paine

http://www.ykfireprevention.ca