Thought some of you might be interested in how far this has gone. The
truss manufacturer was contacted to provide information on the
structural capability of the truss. They refused to provide anything
saying that their product will support any kind of load.
Consequently, sections of truss had to be sent out to a lab, with
Sammy's installed, so see if the truss can support it. The minimum
fail was 524#. The building inspector is reviewing this to see if it
is acceptable. Keep in mind that this is for 7 ft of 1-1/4" CPVC.
Next up: seismic.
The building inspector is demanding calculations from the structural
engineer (it was originally me, but I was able to pass that on) that
a Sammy Sidewinder in a 2x4 will support 7 ft of 1-1/4" CPVC. He is
refusing to inspect the project and the sheetrock is being held
up. The first 2 weeks of this process was to convince him that
Sammys are acceptable to NFPA 13. The third week was to convince him
that a Sammy Sidewinder can be screwed in horizontally ("that's not
how I interpret it..."). We are on week 4-1/2. I calculated the load
based on 10 ft of 1-1/2" CPVC (figuring a conservative overage -
actual hanger spacing around 7 ft and all but 3 pieces 1-1/4"). He
rejected them today saying the load analysis was based on 10 ft and
not 7, so we had to start the process over again.
BTW, he accepted the plans with Sammy hanger details and said nothing.
That, in a nut shell, is why I am involved.
Sam Adams, I hear you calling.
At 05:21 PM 6/21/2010, you wrote:
>And of course Todd I'm going to get on my old horse: If you're being
>the sprinkler guy on this why are you even caring about the load
>holding abilities of the building? The code says the building needs to
>hold up X weight of sprinkler piping, water and fat guy. You provide
>the point loading value to that weight and the owner, through his
>highly paid and highly skilled reps, architect, GC, structural,
>whomever is driving that part of the boat makes sure the building is
>adequate. If you're also being the structural on this then go for it.
>
>On Mon, Jun 21, 2010 at 10:59 AM, Richard Mote
><[email protected]> wrote:
> > If you look at the load limit tables from some of the hanger manufacturers,
> > you will notice that the numbers do not always equal 5 times the weight +
> > 250 lbs. This was pointed out to me by a P.E. reviewing a set of
> plans I had
> > submitted. Subsequent conversations between the hanger manufacturer in
> > question and U/L reveled the following.
> >
> > U/L has a set of criteria, hangers and hanger devices have to meet in order
> > to be listed. These involve shake tests, pull out, bending
> moment, twist off
> > and a bunch of others. Any hanger that meets U/L's shake and bake
> tests gets
> > listed. Now for the kicker, the listed hanger may not and often does not
> > meet the 5 X + 250 criteria.
> >
> > What NFPA 13 says in its own inimitable round about way is this. Use a
> > listed hanger assembly, if you don't then engineer it to meet all of the
> > criteria in 9.1.1.2 (2007).
> >
> > One added point, nothing is specifically listed in NFPA 13. NFPA 13 does
> > give some example illustrations of representative listed product however it
> > does not specifically list or indorse any products.
> >
> > You can't always go be the illustrations either, for example NFPA 13 (2007)
> > Figure A.9.1.1, top row third from the left shows a split ring, neat little
> > hanger especially for sensing line piping and exposed pipe in atriums and
> > the like. Problem is last time I went to order them I could not find a
> > listed split ring from any manufacturer. Now go two spaces to the right,
> > pipe clamps, try to buy a listed 12" pipe clamp can't be done. I
> could go on
> > but there is real work to be done.
> >
> >
> >
> > Richard L. Mote ET
> > Designer
> > Rowe Sprinkler systems, Inc.
> >
> >
> >
> >
> >
> >
> >
> > ----- Original Message -----
> > From: "Chris Cahill" <[email protected]>
> > To: <[email protected]>
> > Sent: Monday, June 21, 2010 12:51 PM
> > Subject: RE: Hanger capacity
> >
> >
> >>I have seen recently where the fine print on a load factor already included
> >> the 250 plus 5x. In my case your 300# would actually be 1750# yielding
> >> 300#
> >> useful for our intent. It wasn't what you are working on, just check the
> >> fine print or talk to the mfg. Of course at 300#/5#/ft = 60 ft which is
> >> 4x
> >> over designed if this is the case.
> >>
> >> Chris Cahill, P.E.
> >> Fire Protection Engineer
> >> Sentry Fire Protection, Inc.
> >>
> >> 763-658-4483
> >> 763-658-4921 fax
> >>
> >> Email: [email protected]
> >>
> >> Mail: P.O. Box 69
> >> Waverly, MN 55390
> >>
> >> Location: 4439 Hwy 12 SW
> >> Waverly, MN 55390
> >> -----Original Message-----
> >> From: [email protected]
> >> [mailto:[email protected]] On Behalf Of Todd
> >> Williams
> >> Sent: Monday, June 21, 2010 11:40 AM
> >> To: [email protected]
> >> Subject: Hanger capacity
> >>
> >> I am having to go through some calculations on hangers to see if a
> >> particular truss can handle the sprinkler pipe. The problem is
> >> involving Sammys and since they are not specifically listed in NFPA
> >> 13 (2002), we need to do the calculations. My question has to do
> >> with the swivel rings.
> >>
> >> Section 9.1.1.2 requires the 5x wt of water filled pipe + 250 lbs.
> >> According to the PHD Manufacturing literature I have, a 2" swivel
> >> ring has a design load is 300 lbs. If we deduct the 250, you have 50
> >> lbs left. Divide that by 5 and you get 10 lbs as the maximum weight
> >> that can be supported. Since 2" water filled pipe weighs 5.17 lb/ft.,
> >> the maximum span a 2" hanger can support and meet the NFPA 13
> >> requirements is 1" - 11". Am I missing something here?
> >>
> >> 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)
> >>
> >> _______________________________________________
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> >> [email protected]
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> >>
> >> 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
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> >
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> >
>
>
>
>--
>Ron Greenman
>Instructor
>Fire Protection Engineering
>Bates Technical College
>Tacoma, WA
>
>Member:
>AFT WA 4184/AFL-CIO, SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC
>_______________________________________________
>Sprinklerforum mailing list
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>
>For Technical Assistance, send an email to: [email protected]
>
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>(Put the word unsubscribe in the subject field)
Todd G. Williams, PE
Fire Protection Design/Consulting
Stonington, CT
860.535.2080
www.fpdc.com
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