As best I can tell there's no listed bracing method for longitudinal seismic bracing for CPVC. Traditionally we've addressed this by placing a tee with a short pipe stub perpendicular to a main and braced that perpendicular pipe with a "lateral" brace, which acts longitudinally on the main. The downside to this is that it's not concentric to the main, but it's pretty close.

Is there a better way to brace CPVC pipe longitudinally?

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I've looked for it but I'm having a tough time coming up with the code section. Where does the requirement for a bell on the face of the building come from?

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From my uneducated perspective both concrete anchors and wood attachments that most people use in the field are not the prescriptive methods outlined in NFPA 13, but instead listed products that are easier to install.

In the interest of learning more about what's actually preferred by contractors, are there any good articles or book content anywhere that could help bring me up to speed on these various hanging attachments? Any help is appreciated.

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A project we're working on has an existing basement area that is broken up into many small existing rooms. Each room has varying ceiling heights and different grid directions.

The remodel that is going to be done will change all of these small spaces into three areas with a consistent new ceiling height that is about the average height of the existing ceilings.

If you are the engineer preparing bid documents in a scenario like this, would you call out for full pipe replacement, or only to modify the existing branch lines?

I would be interested in how others approach this issue prior to bid.

On one hand, modifying the existing system has the potential to save a significant amount of pipe, but could require some large stretches be raised to accommodate new ceilings and would require a good handful of labor to relocate sprinklers.

On the other hand, while an all-new pipe arrangement may cost more in material, it would be better able to coordinate with new HVAC ductwork and ceilings in the space and could possibly reduce the labor time with a pre-fabricated install.

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Hope everyone is having a great week. We're wrapping up this week's Daily Forum with a poll for use of software for hydraulic calculations. Don't see the poll below? Vote here.

If you would like to see your question (or poll) posted, please send it in or email us at info@meyerfire.com. Thank you!
​

Someone had asked about life safety Revit families and any recommendations. We do fire alarm design and are increasingly seeing BIM become the standard when working with architects.

Does anyone have any recommendations on where to find quality fire alarm Revit families? We're not manufacturer-specific design but are looking to improve our older basic devices.

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I've taken technical writing courses and have experience working with MasterSpec, US Military specifications, vendor specifications, and various ownership standard specifications.

I'm giving an internal training to our younger staff and I'm particularly interested in opinions from contractors and vendors who regularly read a variety of specifications for bidding.

What advice would you give for those who write specifications? I'd be interested in helping train our staff as well as improve myself.

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In my experience I've seen a handful of methods in Revit to create life safety plans, and in general they're all developed by the teams I've worked with using a combination of "rooms" and "railings" to calculate occupant loads and travel distances. 

Is there any third-party add-ins or software that others use that could possibly help streamline these efforts?

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For years on my code calls I have asked the Authority Having Jurisdiction what the maximum distance the nearest hydrant is allowed to be away from a building's fire department connection. I get answers that range from 50 feet to 400 feet or even more.

I was looking into the code basis behind this question, and the only applicable section that I found is the International Fire Code, Section 507.5.1.1 that addresses hydrant locations for standpipe systems:

"Buildings equipped with a standpipe system installed in accordance with Section 905 shall have a fire hydrant within 100 feet (30 480 mm) of the fire department connections. Exception: the distance shall be permitted to exceed 100 feet (30 480 mm) where approved by the fire code official."

Is there any relevant requirement for hydrants near fire department connections for sprinkler-only systems?

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Pressure Reducing Valve are commonly used to prevent excess pressure upon systems when supplies exceed the NFPA limit of 175 psi.

There has been much discussion regarding the 'application' of these valves when hydraulic calculations are being provided to the discharge of the PRV and determining the pressure margin available.

Currently, we have been instructed to calculate the system back to the PRV, use the PRV's friction loss calculator to determine friction loss through the valve and subtract that from the outlet setting to establish outlet pressure. This is then used as the available pressure at the outlet; minus the demand and you're left with the margin.

I'm not sure that I agree that the valves 'friction' loss need to be considered unless you are at a point where the PRV can no longer provide the set pressure (when the supply is unable to provide sufficient inlet pressure to overcome the internal friction loss).

Are there any 'papers' written for direction or other sources anyone might recommend?

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A dormitory has 1/2-hour fire barriers separating each residential unit. On each side of the 1/2-hour wall, penetrating the 5/8" gypsum, are shower valves that serve showers within bathrooms on each side.

The shower valves have the valve assembly itself and an opening that's covered with a metal escutcheon. These would qualify as a membrane penetration under the International Building Code.

For back-to-back vales in the wall, how is this commonly addressed to still maintain the 1/2-hour fire resistance rating?

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Amazon is selling fire sprinklers, escutcheons, and sprinkler guards. Some are UL Listed. But many are not listed for use together.

Because of the strict code requirements for installation and testing, is this appropriate marketing?

Who is liable for improper installation and system component failure? Who approves this?

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Have a project where the client is wanting fully-concealed sprinklers, but the project is insured under FM Global. FM does not approve any fully-concealed sprinklers as quick response.

However, under NFPA 13, light hazard spaces are required to have quick response sprinklers.

How do you normally address this conflict?

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​We're located in a seismic area where PT decks are to be considered cracked concrete for the purpose of hanging and bracing. We see a lot of the Dewalt Mini Undercuts and now the newer Hilti HDP-TZ inserts being used to hang up to 4" pipe from the concrete decks. The data sheets show them with pullouts of under 240lbs.

​How can these be used to hang ANY sprinkler pipe if the minimum required capacity of the hanger assembly is the weight of the water filled pipe plus 250lbs?

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We have a project where a control module is connected to the mechanical controls that is programmed to the variable frequency drive for a fan on a large unit. When a duct detector senses smoke, the control module (which is normally-open circuit) will close the circuit, sending a signal to the mechanical controls which shuts down the unit.

On this project we had a bad set of control modules that didn't work. We discovered this in testing with the local jurisdiction, and swapped out the modules and the system now works correctly. 

Both the jurisdiction and I wondered whether this normally-open arrangement is acceptable. If a control module were to fail, the duct detector would not be able to close the circuit on the module and the fan would remain running. In this scenario, there would be no supervision or way to know that the control module failed other than someone standing at the fan or finding the issue during testing.

My inclination is that in the future these modules could be normally-closed and open upon duct detection. That way if the module fails and opens on its own, the unit will shutdown in a "failure" mode.

Is it code required that this arrangement be fail-safe?

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Basic question but I don't know the history - why do we limit pipe to 21-foot lengths? Manufacturing limitation? Transportation? Just curious on the history there.

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NFPA 14 requires standpipes to be full flow tested for the acceptance testing.

Automatic standpipes are fairly straightforward to test, but how have you seen this applied for manual standpipes in mid-rise buildings?

Is this a worthwhile test that will uncover design/installation flaws?

Also, is there any compromised method to meet this requirement?

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In a residential dwelling unit of a high rise building, would a drum light fixture (7"h x 14"d) qualify as an obstruction?

It’s a concealed head in a residential unit of a senior living building.

The contractor – of course – doe not have exact dimensions because it wasn’t reflected on the plans and was added later as a lighting option and only caught by my inspectors during Rough-In. As it is installed, the head is a few inches from the fixture in some units and “a few feet” in others. They want to add a head on the other side of the light, approximately 3 feet -4 feet away citing NFPA 13 8.10.6.2.1.4.

I feel that the light, while an obstruction, doesn’t count as continuous nor does it meet the requirements of a baffle, so if they want to add another head it’d have to be at least 6 feet away to prevent cold solder.

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This question would be good for the seismic bracing experts in the group: NFPA 13 and ASCE/SEI 7 address the Component Response Modification Factor (Rp) as a ductility of the system. It comes into play when determining the seismic design force using the ASCE/SEI 7 method (not the simplified method used in NFPA 13).

NFPA 13 states several times that this factor (Rp) is 4.5 for steel systems (NFPA 13-2016 A.9.3.5.9.1 and E.3). The only mention of plastic pipe systems is in Annex E.3 where it states an Rp value of 4.5 for "high-or limited-deformability piping with joints made by threading, bonding, compression couplings, or grooved couplings", and an Rp value of 1.5 for "low-deformability piping such as cast iron and non-ductile plastics". Is a Response Modification Factor of 1.5 suitable for CPVC pipe?

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NFPA 13 (2016 Section 7.1.2 or 2019 Section 30.3.1) requires a relief valve on all wet pipe systems. The only exemption is where air reservoirs are installed to absorb pressure increases, then a relief valve isn't required.

This seems straightforward but I don't recall seeing independent relief valves on the far majority of the wet pipe systems I've come across. How is this requirement typically met from a design standpoint? Am I missing something or looking in the wrong place?

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If you have an open ceiling (both corridor and adjacent rooms), with a lot of ductwork and plumbing hugging the deck that may cause issues for sprinkler discharge, can you consider it obstructed construction and move the upright sprinkler 22" down from the deck to help avoid the obstructions? (Per NFPA 8.6.4.1.2)

No ceiling tile, ordinary hazard, not large beams either. 

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Is there ever a requirement to have additional valves on either side of a fire sprinkler backflow preventer assembly (which includes two vales already)?

My understanding is that if the center backflow body needs to be replaced, it can be replaced by closing the valves that are part of the assembly, removing the center body, and replacing it with the same model center body as the original backflow preventer. Correct me if I'm wrong, but I believe this still retains the listing of the backflow preventer.

Had a review comment for a project in Illinois that an additional OS&Y valve is required on either side of the backflow preventer, which is in addition to the ones provided with the backflow preventer assembly (Illinois Plumbing Code IPC 890.1130 g 2). To me this doesn't provide any benefit to the system, but only introduce additional repair/failure points and provides two more possible locations where the system could be put out of service.

Have you ever seen this before?

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We had a record month in April with the most discussions to date. Thanks to all those who come to learn and share their expertise and help make this community more impactful. Here's April's top commenters: