Standard Practice to Clean Pipe in Construction?

9/16/2021

I am reviewing a building under construction for a client, specifically the wet sprinkler system installation.

There was a problem where the installer left caps off the pipe both on pipe being stored and pipe installed at the ceiling. My client stated concerns about debris falling into the pipe due to other trades doing work in the area and requested that the sprinkler installer perform corrective measures, they proposed using compressed air to blow out the pipe.

The client wants them to provide some type of justification, industry standard or NFPA guidance that says this is an acceptable means.

I looked in NFPA 13 and NFPA 25 and only found how to deal with in-service systems that have obstructions.

Has anyone dealt with a similar situation or know what the industry standards are for cleaning out pipe during the construction phase?

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14 Comments

Alex

9/16/2021 08:00:14 am

Hi Anonymous,

The only thing I've heard of is flushing underground piping before connecting to the sprinkler system.

I cant see why using compressed air to clean the pipe would be an issue/insufficient. My search this morning came up incomplete as well in terms of a code or standard outlining the cleaning process.

Hopefully someone else knows of a code.
Alex

Jon

9/17/2021 08:10:35 am

I did a lot of research too and I couldn't find anything either, its all about already installed and in use systems.

Jesse

9/16/2021 08:10:08 am

No issue with blowing the pipe out. You didn't find anything in 13 or 25 because it not within the scope of those standards. Either compressed air or flushing them should meet your needs.

JOn

9/17/2021 08:12:11 am

Yeah thats what I told both the client and the contractor but the contractor wants something more substantial than the contractor's word.

James

9/17/2021 08:14:59 am

Photo or video documentation of the pipes stored, or interior photos of the pipes before they go up?

More hassle, but it could settle the uncertainty.

Zackery Geddies

9/16/2021 08:28:52 am

When the pipe is hydrostatically tested at 200psi and drained you are essentially flushing the pipe, same as when the alarms are flow tested you are essentially flushing the pipe.

9/16/2021 08:35:43 am

According to NFPA 13 (2019) §16.6, all sprinkler systems should have arrangements for flushing. If there is actual evidence of foreign materials inside the sprinkler piping that would be of sufficient size to plug a sprinkler, flushing with water would be warranted. In my opinion, using compressed air is likely not going to work. Annex D of NFPA 25 provides some helpful guidance on flushing procedures.

9/17/2021 08:15:02 am

Thats sort of what I alluded to, but the client wants the contractor to do something to show that theres no debris in the pipe while its still being installed, they've been very delinquent about keeping the pipe protected while its stored and installed in areas where other trades are working. I did read the annex of 25 a while ago, I had no idea what the hydropneumatic flushing was until I read that section.

David Kendrick

9/16/2021 09:42:20 am

My curiousity is what were the performance requirements of the project?
Is there a directive in the specifications to have caps on the pipes?

9/17/2021 08:18:23 am

The pipes from from the factor capped and the client was unhappy that they found stored pipe in work areas without them. Apparently one of the client reviewers found a lot of dirt inside one of the uncapped sections of pipe and that set the whole thing off. There are some elbows facing the ceiling in areas of work where stuff could get in there, the client asked the contractor about keeping debris out of the pipe and the contractor just sort of waved them off which the client didn't like. I'm not sure if a RFP, spec or code requirement to keep the caps on but its like keeping the element guard on a sprinkler until the area is done with work to protect the bulb.

Craig Hanson

9/16/2021 10:00:05 am

Before I became an Fire Plans dude I was a Fire Sprinkler fitter for many years and there is some things to consider. 1) pipe never shows up on job sites with protective caps. Back in the day you would only see this on threaded pipe to protect the threads. It is the fitters responsibility to ensure the pipe is free from obstructions. There was a lumber mill that bunt down because a 4x4 was left in the pipe. No amount of flushing would have fixed this. I have also been on a job site that had union and non-union fitters on the same project. The result was some sabotage and we had to tape off our open mains at the end of the day. Hydraulic testing does not fix debris in the pipe, it just moves it. when you fill a system up for the 1st time you will know right away if there is rocks in the pipe as you will hear it!. If there is suspected debri in the system there are only 2 ways to correct it. 1) take it apart, all of it. 2) back flush each line from the most remote to the valve. I have done this to many dry systems that get full of corrosion. Its time consuming and requires special equipment. Bottom line, debris may get into pipe while on the ground and its all fitters now how to spot it and correct it before putting into the air. Stuff in pipe after it is hung is next to impossible unless it was placed there.

Dave

9/16/2021 10:24:27 am

What Mr. Hanson said above ^^ ! (I always tell my design trainees, listen to your fitters, or former fitters, they can teach you a lot!) Also, what Mr. Kendrick asked, were there specs on the job? Because I have seen specs that say to protect the ends with caps or plugs while pipe is being stored, but in decades, I have never really seen this done, no competitive bid is going to include the material and shop/labor time for this exercise, and it is not industry standard. It's up to the fabricator to make sure any "coupons" (the drilled-out discs) are retrieved, or hung from the pipe if field-cut. And up to the fitter to make sure no debris fell into the pipe before being installed. And they can't be expected to close-off each end of pipe as it is being installed. Like Mr. Hansen said, I HAVE seen odd things found in the pipe, either flushed up through the underground, or intentionally stuffed inside the pipe. While the safety concern expressed can be appreciated, in my opinion, it's a misguided and unrealistic solution.

Jerry Clark

9/16/2021 01:06:30 pm

This is why its important to look inside the pipe at the same time you do your weld inspections. I've directed fitters to blow debris out many a time, and on some rare occasions I've rejected pipe that had excessive rust due to extended outdoor storage. It's like Craig said, once it's hung, its too late.

mike

9/18/2021 02:55:11 pm

Flush with water including the drop IMO. use masking tape over the ends daily. Ounce of prevention is worth a pound of cure.

Standard Practice to Clean Pipe in Construction?

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