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Re: RE: Pipe sizes

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Word of caution about pipe vs. tube.  We came to know of the differences
between these two and how the "trade" understands what an architect or an
engineer has specified thru a claim settlement.  When you want to specify a
hollow section that has outer dimension controlling than specify 'tube"
otherwise "pipe".  To avoid confusion specify thickness regrdless of pipe or
tube.  Specifying SCH X for pipe may work but I won't take any chances with it.
 We also came to know that for a structural application most fabricators were
used to seeing "tube" and for most of the  mechanical application "pipe".

Shashi Bhakta

>>> Harold Sprague <harold.sprague(--nospam--at)> 10/27/98 09:44AM >>>
If it is intended as a structural application, I would specify pipe per AISC
standards (ex: Pipe 1 1/2" Std.)  
Standard pipe is Schedule 40, Extra Strong is Schedule 80.
I let the architects tell me what they want for a handrail.  Don't be too
hard on the architects consider the following:
    OSHA says 1 1/2" min. nominal diameter.  
    UBC and 2000 IBC says 1 1/4" min dia and 2" max diameter.  
    ADA says 1 1/2" O.D.  (Have accepted  1 5/8" O.D. or 1 1/4" nominal)
Harold Sprague, P.E
The Neenan Company 
harold.sprague(--nospam--at) <mailto:harold.sprague(--nospam--at)>  

-----Original Message-----
From: Jim Kestner [ mailto:jkestner(--nospam--at) 
<mailto:jkestner(--nospam--at)> ]
Sent: Tuesday, October 27, 1998 9:17 AM
To: seaint(--nospam--at) <mailto:seaint(--nospam--at)> 
Subject: Re: Pipe sizes

One of the mechanical engineers in our office gave me a reference that
indicates that Schedule No. = 1000 x P / SE, where P is the operating
pressure in psi, S is the allowable bursting stress at operating temperature
in psi and E is the quality factor based on the casting method. 

Our office is has been  using the HSS designations for structural and
architectural applications. Does anyone know whether for pipe designations,
we should be using nominal or actual dimensions? example: HSS 1.900 x .145 

Jim Kestner, P.E. 
Green Bay, Wi 

Robert Rollo wrote: 


I have had a curiosity question for quite some time.  Sure, I know of the
existance of "schedule #'s" for pipe sizing (SCH 10, 20 , 40 , 80, 120), but
what does that really mean?  What is the history of these numbers?  Whose
"schedule" is it? 

Despite repeated reminders, I can not seem to get my architects to quit
indicating 1 1/2 " SCH40 handrails, whick exceed maximum allowable OD.  Does
anyone out there specify round tube per A500B like 1 1/2 x 1/8 for
handrails?  I often see 1 1/2" SCH10 for rails, which are compliant. 

Thanks in advance for help with this, its driven me crazy for years. 

robert d. rollo, PE 
Corporate Associate 
(806) 747-0161vox 
(806) 747-7146 fax