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Listed heat tracing - do they have one specifically listed for branch lines yet?

Listed heat tracing - do they have one specifically listed for branch lines yet?

Listed heat tracing - do they have one specifically listed for branch lines yet?

(OP)
Being in the deep south I recently had a couple jobs where the mechanical engineer specified heat tracing for sprinklers under an open canopy.

As far south as I am if the building is unheated but insulated we've never had a problem but a branch line exposed to the outside will eventually freeze and burst.

From a 2010 article

Quote (Ken Isman 2010)

"Heat Tracing for Fire Sprinkler Systems"
Heat tracing can be used on risers and mains of fire sprinkler systems to prevent the piping from freezing. As of right now, heat tracing cannot be used on branch lines of fire sprinkler systems unless the heat tracing receives a special listing for this use, and we are unaware of any companies that have received this special listing.(Isman 2010)

Mr. Isman goes on to say how he doesn't think it is possible to develop a listed heat trace system for branch lines but I suppose anything is eventually possible.

Does anyone know of a system that is listed for branch lines? I bet the answer is no but I got to ask anyway.

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

I have used them many times in the south. Some in the very state you are in.

Raytheon is the name you are looking for.

R/
Matt

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

SD2 raises a good question because I haven't found a cable listed by UL or FM specifically for branch lines. From page 3 of the Pentairthermal installation instructions:

Quote (Pentairthermal)

NFPA 13 (Standard for the Installation of Sprinkler Systems) allows Listed electrical heat tracing to freeze protect fire suppression systems including supply lines,standpipes and branch lines containing sprinklers. XL-Trace is c-CSA-us Certified for use on fire suppression systems under CSA C22.2 No. 130-03 for Canada and IEEE 515.1-2005 for the US. The system covered in this manual includes supply lines, stand pipes, branch lines and sprinkler heads.

The indicated IEEE standard is not referenced in Section 2.3.7 of NFPA 13 Section 2.3.7. Interestingly the heat trace controller is also not listed other than to the aforementioned standards. My jurisdiction has accepted these given they are listed and the IEEE standard is an ANSI recognized standards writing organization. The fact that the system can be supervised by a fire alarm system does alleviate many of my jurisdiction's concerns. Frankly, it's a good solution when it's properly designed and installed. My experience is that these systems commonly require 2-3 plan reviews because of the level of detail required and coordination between the fire protection (water based and fire alarm & detection), electrical, insulation and general contractors.

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

(OP)
I've been looking for one specifically listed for branch lines and I couldn't find it.

Personally, from what little I have read so far, I don't think these are a solution other than providing freeze protection to a short piece of exposed main. The more I read the less appealing it seems.

And if I got it right if it gets 10 below you can forget it anyway?

To risky for me. I do not like it when someone outside my company can put me in a position to be responsible for something we didn't do.

Anyone know about the costs? Figure a total of maybe $5,000 for 12 head aux. dry system that I can feel comfortable with. What are we looking at in monetary terms for the same 12 heads on a heat trace system?

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

The ability to keep the pipe => 40F at given design temperature is as much a function of the selected insulation and the quality of its installation as it is the selection of the appropriate heat tracing cable, heat trace controller, and its installation. The pipe diameter, design of the hangers so they don't become a heat conductor, placement of the thermocouple that activates the heat trace controller, the power tap connection from the heat trace cable to the controller and the insulating material's conduction factor are equally important.

I currently have an installation underway at the local airport with about 600 feet of 6-inch feed main that feeds the heated area of a 180,000 sq. ft. terminal expansion. We asked about the possibility of moving the main into the heated space to avoid the 800 linear feet of heat trace cable, 4 heat trace controllers, 4 separate electrical disconnects and all the insulation. No mas, this is what they want. So I can see several hours of acceptance testing in my near future.

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

(OP)

Quote (Bottom of Page 4)

XL-Trace systems are also UL and ULC Listed for freeze-protecting sprinkler supply lines, standpipes up to 20 inches in diameter and branch lines not containing sprinklers.

There was a job that I was going to bid where the engineer of record specified heat tape on everything and after doing some research it made me feel so uncomfortable I just backed off.

This was in a hospital and I could just see lawyers having a real good time if something happened.

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

Interesting.


This one truly boils down to listed/acceptable. Now I am wondering why UL listing omits sprinklers... You would think they understood the defining attribute of a Branch line is..., Sprinklers.

It has been years since I bought one, but gut reaction is the price you named may be a couple k light. The selling point being no other sprinkler system requiring more expensive maintenance.

R/
Matt

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

Also consider branch lines being the piping from standpipes to hose valves.

When this comes up in the bid market I typically punt or sell a dry valve/dry sidewalls and exclude the heat trace spec on my proposal. Once the GC knows how much it costs my company is usually out. Someone will inevitably forget to include it and they'll get the contract and all the headache that comes with it.

I don't think heat trace is a good solution to the freezing problem. A lazy architect or engineer does.

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

(OP)
when this first came up I did have some concerns about it but after reading up on the situation my concerns are now big. so big in fact that if it comes up again I'll just back off because right now there's more work out there, that's good work without the risk, where I don't need this type of work.

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

Keep in mind that some heat trace systems do not report failures in the cable...so you can lose heat without knowing. I would suggest a system that monitors the integrity/functioning of the heat trace cable so that when there is a failure it alerts someone instead of failure and freezing pipe. I'm sure there is even an option to monitor the heat trace system with a fire alarm module so it'll kick out a supervisory/trouble signal when the heat trace system fails.

RE: Listed heat tracing - do they have one specifically listed for branch lines yet?

(OP)

Quote (Matt)

It has been years since I bought one, but gut reaction is the price you named may be a couple k light. The selling point being no other sprinkler system requiring more expensive maintenance.

R/
Matt

Probably but I was thinking something real small say 6 sprinklers.

That said heat trace does not impress me.

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