I just got one in to review where the designer used the Room Design method for am NFPA 13 retirement home corridor, but did not use the Corridor 5-sprinkler provision. He was considering the corridor the "room", but really didn't even include the entire corridor. I think I can help him out by directing him to the 5-sprinkler corridor methods (opening protection doesn't even come into play). It is a corridor protected by a single row, BUT another corridor tees off it at 90-degrees.

Do these "tee" intersections negate the "single row" provision?

Each leg IS protected by a single row so I'm thinking this does not negate the intent. Thoughts?

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Has anyone dealt with a building structure comprised of steel hexagonal castellated beams spaced 36" apart with a wood plank deck?

Would this be considered obstructed combustible construction?

Also, has anyone seen a combustible concealed space head which is "listed" for such structure?

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When doing zone of influence calculations, NFPA 13 doesn't seem to be specific about whether the weight of drops and sprigs should be included in the weight of the branch line tributary to the lateral brace on the cross main. It states "The zone of influence for lateral braces shall include all branch lines and mains tributary to the brace, except branch lines that are provided with longitudinal bracing or as prohibited by 9.3.5.9.6.1" (NFPA 13, 2016 Edition, Section 9.3.5.9.6)

This ambiguity is frustrating because long drops are quite heavy and can double the weight in the calculation if they are included. It seems like some argument could be made that they aren't "tributary" to the lateral load because they can "swing" independently, but should their influence be considered negligible?

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Can someone explain the process for determining if a standpipe system needs to be designed for seismic considerations?

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Looking for guidance on pressure gauge selection. Is there a requirement for a maximum pressure gauge for testing residual pressures of 40-50 psi on suppression systems?

Wondering if any pressure gauge is adequate or if there's specific guidance I should be following on gauge selection.

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Clearance around fire sprinklers - NFPA 13 (2016) addresses clearance around sprinklers in 9.3.4.11, A.9.3.4.11, and 9.3.4.11.1. The language is very vague & ambiguous. Could anyone elaborate on this for me?

What type of ceilings needs to have clearance around fire sprinklers when using hard pipe (not flex drops)?

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Does anyone have any experience with determining an appropriate design criteria for protecting rectangular hay bales stacked to about 20 ft. in a 25-30 ft. metal purlin building?

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Can we use CPVC pipe material for the inspector's test and main drain?

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When testing a fire pump from the roof is there a calculation that is necessary to ensure that the flow test is accurate (given pipe sizes, elevation increase, etc)?

NFPA 25, 2014 handbook states that flowing from the roof in the explanatory material is somewhat acceptable (NFPA 25, 2014: 8.3.3.1.3). However, NFPA 20, 2013 A.4.20.3.4(2) has a sample hydraulic calculation sheet for sizing the test header when not using the table which appears to take into account items like friction loss, elevation, etc.

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Question about doing hydrostatic testing using compressed gas such as nitrogen rather than using a test pump. Do you know of restrictions to using compressed gas by the standard?

​I know there are “other” safety issues when working with compressed gases. Just asking about using high pressure gas for the acceptance test.

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Sorry - seems to have missed the question posted for this one. If you received a blank email today, my apologies. Now onto the question:

Where can I find guidance as to whether or not an oil transformer requires sprinkler protection? I'm specifically looking into standards or requirements concerning deluge sprinklers for oil transformers. Thanks in advance.

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Does the proximity of a residence and the number of windows on that residence make a difference in which system type is used (between NFPA 13, 13R, or 13D)? What are the restrictions that would impact the system type?

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We have a project which is on a steep slope (the bottom of the site is about 120 feet lower than the top of the site). If we attach a fire main to the bottom of the site, the fire pump we have won't have much issue with keeping the city pressure at a 20 psi minimum or above.

If we attach to the water grid at with the fire service main at the top elevation of the site, we will probably need a suction control valve in order to keep the city pressure at 20 psi at the top elevation since the available water supply is so low.

My question is - if we pull pressure on a city's system at the low elevation, do we have to chart and consider the rest of the water supply network?

There's a chance if we pull the water supply down to 20 psi at the lower elevation that the system at the higher elevations would be well below the 20 psi due to elevation pressure loss. Thanks for your input!

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My daughter is in fifth grade this year and will be picking out a science fair project.

She really wants to choose a topic relating to fire sprinklers. Obviously, I'm doing everything I can to support this.

I'm wondering if anyone out there might actually know of sprinkler-specific science fair projects that have been done in the past? Or maybe some ideas? Thanks!

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What is the max gpm you can get with a 6” dr 18 underground?

We had a flow test of static 68 psi residual 48 psi flowing 1950 gpm. With 3111 gpm @ 20 psi. Some one is telling us the max gpm is 800 gpm. How is this possible?

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A 4-inch schedule 40 main is routed parallel in-between two beams and requires a trapeze hanger. The main is 2 ft. from one beam and 8.5 ft. from the other for a total span of 10.5 ft. What is the smallest schedule 10 pipe diameter capable of supporting this main as a trapeze hanger?
a. 2-inch
b. 2-1/2 inch
c. 3 inch
​d. 3-1/2 inch

Solution | Posted 10/24/19

Determine the flow (in gpm) through an extended coverage pendent K16.8 sprinkler at 85 psi.
a. 52 gpm
b. 155 gpm
c. 348 gpm
​d. 1428 gpm

Solution | Posted 10/23/19

Is it acceptable to place the connection for the fire pump test header on the 'system' side of the isolation valve?

I've seen instances of this and it concerns me that there is a potential to render the FDC ineffective during pump testing; not to mention the possible corruption of pump test data due to the influence of the 'stored' water and pressure in the existing sprinkler system.

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I'm designing a system with sprinklers at the ceiling of a large open space. There is a vestibule within this space that has a lower ceiling that requires 3 sprinklers. The client does not want pipe drops or hangers above the vestibule to be visible from the rest of the open space.

The proposed solution is to run a branchline down the wall and horizontal tight to the ceiling. Is there a good way to support this that meets the requirements of NFPA 13 chapter 9? The vestibule has CMU walls and metal stud ceiling.

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A building owner has bought a large old warehouse and in about 6-8 months will convert it into educational spaces. They've asked if over the winter they could drain down the large wet sprinkler system as they aren't planning on heating the space or occupying the building during that time. 

I recommended against it since they'd be without protection during that entire time and a fire could result in a total loss of the building. 

I also suggested they speak with their property insurer, couldn't store anything in the building, and would need to talk with the fire department as it would be a system impairment.

Aside from that, what other barriers would they come across? What would you have recommended?

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This project is a residential occupancy (dormitory) with a sprinkler system designed under NFPA 13. The contractor is using residential-style sprinklers within each unit, but standard-spray sprinklers in the corridor.

The corridor has these standard spray sprinklers just off the main which runs down the corridor. The contractor has provided calculations for the four most demanding adjacent residential style sprinklers, which is fine. He's also provided a calculation for the corridor using five sprinklers.

NFPA 13-2016 11.2.3.4.2 states:
11.2.3.4.2 Where an area is to be protected by a single line of sprinklers, the design area shall include all sprinklers on the line up to a maximum of seven. 

Since the corridor's sprinklers are not residential, how many sprinklers should be calculated in the corridor?

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This is giving me heartburn. A clothing manufacturing company wants to store group IV commodities.

16.1.3 Movable Racks. Rack storage in movable racks shall be protected in the same manner as multiple-row racks.

16.2.1.2 Protection Criteria for Rack Storage of Class I Through Class IV Commodities Stored Up to 12 ft in Height.
​
16.2.1.2.1 The protection criteria for storage up to and including 12 ft shall be the same as miscellaneous storage from Chapter 13.

The definition of Compact Storage Module does not specify passive protection to qualify as such.

My question is: “Is it correct to treat this rack configuration as moveable racks?”

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Solution | Posted 10/16/19

Have a flow test in a semi-rural area that has static pressures of over 130 psi but a residual pressure of 60 psi at just 500 gpm.

A flow test from nearly a decade ago shows worse results - with a static of around 120 and a residual of 20 psi at just 600 gpm.

My initial concern with the older flow test was a partially-closed valve or obstruction in the line. 

With the newer test the residual pressure seems more reasonable, but other than something being wrong with the system is there a reason that would justify a residual pressure less than half the static at only 500 gpm of flow? Perhaps a system fed with small pumps and no tower? What are your thoughts?

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Is there a complete list of points I need to monitor with fire alarm for a diesel driven fire pump?

I can't seem to find a comprehensive/definitive list in NFPA 20 or 72, but I would imagine at least one or more of the following would need to be monitored by code: fire pump running, primary sensor failure, low fuel level, main disconnect in "off" position, main disconnect in "manual" position, low pump room temperature, flowmeter left on, loss of AC power supply, loss of battery (load side of DC overcurrent), over-speed, and engine trouble (low oil, over temp, other?).

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