The expansion is the expansion no matter what fittings are employed, well on unrestrained steel. A fitting does not in itself restrain the pipe. Either the pipe moves or the want to move is translated into some internal force. The effect of the expansion it dependent on the fittings and the restraintment. -----Original Message----- From: David de Vries <[email protected]> Sender: [email protected] Date: Wed, 10 Nov 2010 08:40:57 To: <[email protected]> Reply-To: [email protected] Subject: Re: Pipe Expansion
You are right about whether this is a continuous run of pipe. Putting back-to-back swing joints in a long run can change the dynamics completely. Cast, ductile and malleable iron all have about the same thermal coefficient of expansion as steel. So screwed fittings would be the same as continous welded pipe. The difference that grooved couplings could make depends on the style. If rigid, then it would be the same as screwed fittings, but other couplings have some ability to flex and move, so might be better for such a situation (long, continous run of pipe with big temp swings). Railroad track layers (don't know if that is the right trade name) have this figured out for welded track. Every mile or two they stretch the track with a hydraulic puller to simulate the condition at the highest foreseeable temp. The track then is in tension at colder temps, but does not buckle on a hot, sunny day. Not applicable to sprinkler trade, just a curious thing I learned from the Chief Engr for a railroad here in Chicago while we were surveying his totally destroyed wood trestle which burned following some hotwork by an outside contractor. BTW, a mile of track expands 4'3" from -10F to 110F. Dave David A. de Vries, P.E., CSP Firetech Engineering Incorporated --- On Wed, 11/10/10, Todd Williams <[email protected]> wrote: From: Todd Williams <[email protected]> Subject: Re: Pipe Expansion To: [email protected] Date: Wednesday, November 10, 2010, 10:08 AM Of course that assumes a continuous run of 200 ft. The inclusion of cast iron screwed or grooved fittings may have an impact At 10:52 AM 11/10/2010, you wrote: >Carbon steel: expansion = 6.7 x 10^-6 x L. x delta T. > >Example: 200 feet of steel pipe installed at 30 degrees F and >raised to 100 degrees F. > >6.7 x 10^-6 x 200ft x 12in/ft x 70degrees = 1.13 inches > >Copper: 9.3 x 10^-6 > >The source, Perry's Engineering Manual, puts a range on that >coefficient of 32 to 212 degrees F. For down and dirty purposes, >this should work to foreseeable colder temps. > >Dave > >David A. de Vries, P.E., CSP >Firetech Engineering Incorporated > > > >--- On Wed, 11/10/10, Charles Thurston <[email protected]> wrote: > > >From: Charles Thurston <[email protected]> >Subject: Pipe Expansion >To: "sprinklerforum" <[email protected]> >Date: Wednesday, November 10, 2010, 8:10 AM > > >Hello sprinklerforum, > > Does anybody know of a down and dirty chart or calculator to > figure pipe expansion lengths due to temperature change ? > >-- >Best regards, >Charles Thurston mailto:[email protected] > Coastal Fire Protection/ Myrtle Beach Fire & Safety Group. > AFAA Guest > >Electronic Privacy Notice: >This e-mail, and any attachments, contains information that is, or may >be, covered by electronic communications privacy laws, and is also >confidential and proprietary in nature. If you are not the intended >recipient, please be advised that you are legally prohibited from >retaining, using, copying, distributing, or otherwise disclosing this >information in any manner. Instead, please reply to the sender that >you have received this communication in error, and then immediately >delete it. Thank you in advance for your cooperation > >_______________________________________________ >Sprinklerforum mailing list >[email protected] >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > >For Technical Assistance, send an email to: [email protected] > >To Unsubscribe, send an email to:[email protected] >(Put the word unsubscribe in the subject field) >_______________________________________________ >Sprinklerforum mailing list >[email protected] >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > >For Technical Assistance, send an email to: [email protected] > >To Unsubscribe, send an email to:[email protected] >(Put the word unsubscribe in the subject field) Todd G. Williams, PE Fire Protection Design/Consulting Stonington, CT 860.535.2080 www.fpdc.com _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
