In NFPA 13 under "Location of Hangers on Branch Lines", Section 9.2.3.6 (2016 Edition) states that "wall-mounted sidewall sprinklers shall be restrained to prevent movement."

This section does not relate to seismic restraint, and annex material clarifies as much.

How is this sidewall-restraint typically achieved? 

Many sidewall sprinkler installations have an armover and a drop that goes down the wall before a reducing elbow serves the sprinkler in the wall, and I don't recall ever seeing a means to restrain the pipe (or sprinkler) for steel jobs.

Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Do you have any thoughts or input on the interior exit stair penetration limitations of Section 1023.5 of the IBC? 

I have someone contending that you aren’t allowed to run a “bulk feed” main into a stairtower and then back out again on a different level.  They claim that 1023.5 limits penetrations only to MEP equipment that serves the stairwell itself.  I contend that, especially as clarified in the 2018 edition (although I contend that it was always the intent), any fire protection system is allowed to penetrate such a stairtower as needed, as long as the penetrations are correctly firestopped etc…
 
The confusion comes from the 2015 edition, which reads (emphasis added to indicate the confusion that I think this person is having):

“Penetrations into or through interior exit stairways and ramps are prohibited except for equipment and ductwork necessary for independent ventilation or pressurization, sprinkler piping, standpipes, electrical raceway for fire department communication systems and electrical race-way serving the interior exit stairway and ramp and terminating at a steel box not exceeding 16 square inches.  Such penetrations shall be protected in accordance with Section 714.  There shall not be penetrations or communication openings, whether protected or not, between adjacent interior exit stairways and ramps.”
 
I believe that that person is seeing that “serving the interior exit stairway and ramp” portion of that snippet, and they are applying it to everything.  However, I contend that that is actually applying specifically to “…and electrical race-way serving the interior exit stairway and ramp and terminating at a steel box not exceeding 16 square inches”.  I think that the person is cherry picking what they want it to say, although it is somewhat confusing the way it’s all written on one line.  I believe that if that person really wanted to apply this verbatim, then you would not even be allowed to have combined standpipes that feed sprinkler systems outside the stairwell, or even dedicated sprinkler risers in the stairwell wouldn’t be allowed to serve any floor area outside the stairwell.  Basically any sprinkler riser in a stairwell would only be allowed to feed that specific stairwell…  I think it’s clear that this is not the intent of the code.

Read More Here

Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Solution | Posted 08/21/19

NFPA 13 Section 8.15.4 (2013 Edition) requires certain types of unenclosed floor openings to be protected with closely spaced sprinklers where sprinklers serve as an alternative to the enclosure of the vertical opening. 

What method do you use to determine if the opening requires enclosure, and thus closely-spaced sprinklers? 

As a sprinkler designer, I may overlook something in the Building Code that allows the unprotected opening, or vice versa.

A pre-bid RFI to the architect seems to be the best course, but it would be nice to have something to hang the hat on before the bid is submitted.

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Solution | Posted 08/20/19

​Want to join in? It's not too late - the PE Prep Series is the ultimate PE Prep tool. It's a series of 1-hour, 10-question simulated PE Exams offered weekly with solutions immediately following each exam. Learn more here. ​​​​Every week of the series is retroactive so you can still test yourself with past week exams

Correction on the Week 11 Exam: Question #8 asked for the carbon dioxide quantity in kilograms but the solution was in pounds. The correct answer is 156 lb, or 71 kg. This has now been updated in the series for future users.

I've heard from several installers that small diameter schedule 10 pipe (such as 1-1/4") will warp if there's more than two welded outlets made onto it.

Would any installer/contractors weigh in on how you best combat this problem?

I could see larger diameter (1-1/2" or more) schedule 10 as a possible solution, which also helps hydraulics. I could also see voluntarily going to schedule 40 as a possible solution. Cutting the pipe into shorter segments and adding couplings would also help, but I could see the cost adding up for the labor, couplings, and additional hangers.

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Solution | Posted 08/19/19

The International Building Code requires identification of fire partitions, barriers, or fire walls with 3" letters identifying the wall itself.

I've seen (especially in hospitals) labels for each through-penetration with a UL Listing sticker right below each penetration. Is this a requirement by code, or just a hospital standard?

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Solution | Posted 08/16/19

My son has purchased a condo, (prior apt conversion). They removed the closet doors in the living room related to an air flow vent return on one side when the central air was added.

There is a sprinkler in the center of the former closet. I was told I can not enclose the sprinkler in a closet when I wanted to build the closet doors 3/4 of the way, (leaving 35 inches for the air flow vent). So, now the closet would be only 40" wide. Do you know in MN if I can enclose the sprinkler? Thank you.

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Solution | Posted 08/16/19

Once again great info/insight. Though it made me think.

What if you have a type II hood without wet chem protection? Are sprinklers required? I think yes (following obstruction rules).

To take it a step further, what if you have a type I hood with protection over the required appliances including the plenum but not below the plenum in areas where there are ovens/non-cooking equipment? As an AHJ, I have never required additional protection here. But now I question myself.

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Solution | Posted 08/14/19

I'm considering testing for NICET fire alarm certification. What I don't yet know and would be very interested in is who typically prepares fire alarm shop drawings? 

Do freelance fire alarm designers/engineers make up a large portion of shop drawing preparation, or is it mostly all completed by a fire alarm company's designer? Do large manufacturers (Simplex/JCI) complete all of their own shop drawing work with in-house designers?

Thanks in advance - I'm trying to get a better perspective for my career.

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

White Oak wood having a density of 450, moisture-content of 25% is exposed to a standard fire (ASTM E119) test for 2 hours. What is the expected char depth most nearly?
     a. 1 mm
     b. 64 mm
     c. 72 mm
     d. 224 mm

Solution | Posted 08/13/19

NFPA 20 permits the demand for a suppression system to be between 90% and 140% of a fire pump's rated capacity (NFPA 20-2019 4.10.1 and Annex A.4.10.1). The pressure demand must always be less than the pressure supplied by the pump's performance curve along this range.

Does this concept apply to standpipes? For instance, could a 750 gpm pump provide 1,000 gpm demand for standpipes since it would be running at 133% of its rated flow?

If it can be done, is it good practice?

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

If, during a fire, a total occupant load of 205 people are exiting through a building's main entry (a 7-foot double door with an effective width of 6.5 ft) and the density near the main exit door results in about 0.25 persons/sqft, the time (in minutes) it would take for all of these occupants to exit the main doors is most nearly:
a. 1.5 min
b. 1.6 min
c. 2.2 min
d. 6.3 min

Solution | Posted 08/12/19

When doing thrust block calculations NFPA 13 gives an angle that is the bend off the centerline of the original pipe. 

What angle should be used for a tee or a dead end?

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Solution | Posted 08/09/19

Does anyone know which calculation can be applied (or if there is a calculator available) to determine if an insulated pipe will freeze (or how long it will take to freeze)?

We have a scenario where we specified a heat trace system to be used on branch lines extending from the building to an exposed exterior soffit that is subject to freezing conditions. Due to cost concerns, the school/contractor want to remove the heat trace and just insulate the pipe. Thanks.

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Solution | Posted 08/08/19

Where can I find a contractor the performs internal Water Storage tank inspections per NFPA 25?

The customer is have difficulty as the local contractors do not perform these inspections because of the age of tank and liability. The contractors I have spoken with say that the tank is not large enough to put divers in. The dimensions are approximately 25 -30 foot diameter, and approximately 25-30 feet in height. Then the contractors say due to the age of the tank there is a liability they are not willing to take on. One contractor suggested finding a company that uses drones.

Any suggestions on how to proceed?

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe