Specifying Galvanized for Dry? Nitrogen? Sch40?

8/9/2021

I'd like to ask a question especially to other specifiers out there. Interested in galvanized pipe, particularly on dry systems.

We all know the valid arguments, reasons, and ever-growing evidence against the use galvanized pipe on dry systems. I always find it curious FM Global is still hanging on to it (although it says galvanizing must be applied after roll-grooving).

While the case for nitrogen systems is becoming stronger, and even more cost-effective, I have not seen it going there yet except on military applications, and generally-speaking, owners are not warming up to it yet (maybe I should be a better salesperson). Owner learning-curve is a factor.

At the time of this writing (mid-2021) are other specifiers requiring nitrogen systems across-the board?

Are you requiring schedule 40 pipe on dry systems? Galvanized?

(See also: https://www.meyerfire.com/blog/why-are-dry-pipe-sprinkler-systems-so-difficult )

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8 Comments

Jon Sullivan

8/9/2021 08:25:39 am

We have not seen nitrogen yet in my industry sector which is public transportation on the east coast. We’ve recommended it, but my take is that it will be a while.

However, we do have clients request Schedule 80 galvanized so they are aware of the maintenance issues. Hopefully we’ll come around to nitrogen.

Casey Milhorn

8/9/2021 08:36:01 am

I am not a specifier full time, but I do some consulting on design build or in assistance to some engineers. We are starting to see it "considered" more often and sometimes it actually makes it through the design phase, into the specs, and through VE reviews, to actually be installed. My personal opinion (if I were to own a building with a dry system), would be to use black sch. 10 mains, black sch. 40 lines, using a nitrogen system that has the ability to self monitor and report when nitrogen drops below 98%. The only exception would be to use galvanized pipe where exposed to the weather or in areas near the coast, or other caustic environments, strictly for the external protection that galvanizing provides.

schulman

8/9/2021 08:43:40 am

here in NC the State Construction Office standard is Schedule 10 and 40 Black Steel Pipe on dry systems - only changed recently mind you ...
after years of failing Galv. Systems ...
and no, very little Nitrogen usage ... primarily due to cost ...

James

8/9/2021 08:49:05 am

Not a specifier here - but I can say when I see a nitrogen system included in the plans/specs it is a huge relief and I'm very happy it is there; I try to help make the owner aware of system lifetime and longevity on the backend with contractors, but it can still be a tough ask when nothing is in the bid documents.

At least having it in the bid docs helps us on the install side support the idea and try to help the system life and the owner. Not every contractor agrees I'm sure, but I'm thrilled when I see it in the docs on the front end.

Here in a few years when the C-Factor changes to 120 for black steel and nitrogen on new systems (I believe NFPA 13-2022), it'll be a considerable kickback on the cost of the installed system. Just more reason to get it included.

Glenn Berger

8/9/2021 09:25:11 am

Been specifying Schedule 40 Black Steel with Nitrogen for Government clients for almost 10 years and almost 5 years with commercial clients. Commercial clients have been coming around to N2 once they have experienced a system failure.

Andrew K

8/9/2021 10:06:23 am

This perspective comes from an installing contractor of fire suppression/protection systems in the NYC metropolitan area. In recent years we have experienced an increase in both having nitrogen generators for dry & pre-action systems spec'd in project bid documents, as well as an increased acceptance of such systems when proposed as a change. The nitrogen generator systems for dry and pre-action systems are now more likely to appear on bid documents than not. A guestimate would be in the area of 75% prevalence on projects.
These nitrogen generator systems are mostly spec'd and installed with Black, schedule 40 pipe.

p.s. I am in awe of this forum. Exceptional expertise.

Alex

8/9/2021 11:47:22 am

HI Anonymous,

On the contractor side, I still see some designers requiring the use of galvanized. Although, for any design build, we will use black steel, schedule 40 pipe.

To answer your question, I have not seen others specifying nitrogen systems across the board. Personally, I feel as the industry will go that direction overtime.

Best of luck with your design,
Alex

Scott

8/9/2021 01:08:00 pm

We like to spec Sch 40 black steel with an air compressor with a dryer package. Normally the cost of the dryer package is much more affordable than your nitrogen generator package and will still extend your systems life expectancy to some degree. We've noticed that the Nitrogen Generators in theory sound great and been marketed well to engineers, except that the cost is often never explained in full to the engineering side for proper cost analysis.

Specifying Galvanized for Dry? Nitrogen? Sch40?

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