How much surface rust is there? If it is S40 8-inch pipe the wall thickness is .322 inches (8mm). It will take a lot of rusting to get through this. And if it does get through what do you have - a leak. That is easy to fix with a full circle clamp. I have doubts that the problem is as severe as surmised.
If there is still concern there are ultrasonic and x-ray devices that are available to determine the pipe wall thickness. Contract with a company that does this to eliminate the uncertainty. We should not be throwing away good pipe just because it looks bad. You should know for sure before replacing it. John Hoffman P.E. | Fire Protection Engineer | Facility Engineering Services, KCP, LLC - Burns & McDonnell Engineering | National Nuclear Security Administration's Kansas City Plant | Operated by Honeywell FM&T | 2000 E. 95th St | Kansas City, MO 64131 | ph 816-997-7213 | [email protected] From: Greg McGahan <[email protected]> To: [email protected] Date: 09/20/2012 02:18 PM Subject: Re: black sch 40 painted vs galv schedule 10 Sent by: [email protected] We assume the existing pipe is Blk Sch 40 but we do not know for sure. Most of it has what I would describe as Heave Surface rust, but there are a couple of places where the rust is probably as deep as threads would be. We do not know how old it is, but probably in the vicinity of 25 years. The pipe is in a tunnel that goes from an unconditioned mechanical/boiler room to a vertical chase in the hospital. It is absolutely not conditioned. I do not think there is anyway to classify this pipe as Underground since you can walk through the tunnel. The scary part is that it is the only pipe feeding the hospital and if it failed at the wrong time it would be catastrophic. The primary fdc also pumps into this pipe. Greg On Thu, Sep 20, 2012 at 2:02 PM, Greg McGahan <[email protected]> wrote: > > > On Thu, Sep 20, 2012 at 1:58 PM, Thomas Watt < > [email protected]> wrote: > >> Greg, can I get a little more info please? This has piqued my interest and >> led to more questions. What type of pipe is in there now? How old is it? >> What type of tunnel? How long is the run? Heated/conditioned at all? >> If tunnel is underground can DI be used, (by code I mean) ??? >> >> On Wed, Sep 19, 2012 at 12:01 PM, Greg McGahan <[email protected] >> >wrote: >> >> > We have an UG tunnel with an existing 8" bulk main that is showing >> signs of >> > significant corrosion - currently black pipe - unpainted. >> > >> > We recommended replacing the pipe with galv sch 10 - a competitor has >> > recommended using blk shc 40 and painting it as being a better choice >> for >> > corrosion protection. We disagree but would like some other input? >> > >> > The tunnel does have standing water on the floor most of the time so it >> is >> > always damp. >> > >> > Thanks, >> > Greg >> > >> > -- >> > Greg McGahan >> > Living Water Fire Protection, LLC <http://www.livingwaterfp.com> >> > 1160 McKenzie Road >> > Cantonment, FL 32533 >> > 850-937-1850 >> > fax 850-937-1852 >> > -------------- next part -------------- >> > An HTML attachment was scrubbed... >> > URL: < >> > >> http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120919/e51f2e06/attachment.html >> > > >> > _______________________________________________ >> > Sprinklerforum mailing list >> > [email protected] >> > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum >> > >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: < >> http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120920/11bf43dc/attachment.html >> > >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum >> > > > > -- > Greg McGahan > Living Water Fire Protection, LLC <http://www.livingwaterfp.com> > 1160 McKenzie Road > Cantonment, FL 32533 > 850-937-1850 > fax 850-937-1852 > > -- Greg McGahan Living Water Fire Protection, LLC <http://www.livingwaterfp.com> 1160 McKenzie Road Cantonment, FL 32533 850-937-1850 fax 850-937-1852 -------------- next part -------------- An HTML attachment was scrubbed... URL: < http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120920/5629f5de/attachment.html > _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
