Hi,
Further, a little addition from my side:
The logical usage of concentric or eccentric reducer
depends on the placement of it in the line, in the
layout.
In a vertical run, theoretically, it is immaterial
which way the reducer is put. But if the pipeline
under consideration forms a part of a bank of lines
running as a layer over a substantial length of run,
for the purpose of having a common reference for
supporting structure, it is preferable to have back of
all pipes on the same grid. Otherwise, if it is a
single isolated line, it does not matter at all.
The matter is different in the case of a horizontal
run of pipe. Here, the drainage during shutdown and
testing governs the choice in order to avoid stagnant
and dead pockets. Generally it is adopted as flat side
bottom. But this need not be always true. If the line
is the one which discharges off gases to the flare
system or something like that, and if the
reducer/expander as generally happens, is to be placed
upstream of an elbow which in turn changes the
direction towards up, there is a chance of forming a
permanent vapor pocket if the reducer is kept with
flat side bottom. In this context it is advisable to
have flat side top, so as to release all the trapped
gases out (to the blow-down system, for further
disposal). This may obviate one test vent assembly,
which otherwise would have been essential.
The summary is: use common sense, rather than adopting
any by-laws.
Good luck!
C. V. Gangadharan.
--- Bruce Bullough <bbullough@sebesta.com> wrote:
> Vinay:
>
> It depends on the conditions and use/process, but
> often with ammonia and
> the chance of condensate (liquid Ammonia) use
> eccentric reducers.
>
> ... Bruce D. Bullough ...
> Sebesta Blomberg & Associates
>
> 2381 Rosegate
> Roseville, MN 55113 USA
> 651-634-7344 direct
> 651-634-7400 FAX
> www.sebesta.com
>
> -----Original Message-----
> From: ETSMech User Babrala
> [mailto:btsmuser@tatachemicals.com]
> Sent: Wednesday, August 06, 2003 5:08 AM
> To: <a href="/group/PipingDesign/post?postID=62WAwfrgg5B0KlYTHp59S13j0MXw94MPLgB73bQnrbc4QhuXP3qGZwKWQAkLKOBvwCNCtVQQ0sqn3KO1iWdLRKXm">PipingDesign@yahoogroups.com</a>
> Subject: [PipingDesign] [PipingDesign reducer
> [bcc][faked-from]
> Importance: Low
>
>
> Friends,
> I have a question regarding piping fittings.
> For one of my jobs piping system handling ammonia
> gas, I am not able to
> decide whether to use concentric reducer of
> eccentric reducer. Please
> help me in this regard
>
> Thanks
> Vinay.
>
>
>
>
>
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