Maybe Rajesh wanted RMS definitions and a long reply about the dis/advantages regarding spiral vs. circumferential grooving of the face?
Most of these questions are covered by various codes, but digging deeper never hurts.
http://www.boltex.com/facings.htm
Let's face it folks, process piping is not rocket science (although it is certainly *required* for rocket science to exist), the codes are there for a reason.
Unless advanced R&D or specialized applications are involved, please follow the codes.
Paul
> not much. it has to be flat and even. imperfection is taken care
of by the
> gasket. the 125 rms roughness is about economics. however the
type of gasket
> and the type of flange face (raised face, rtj, etc)do counts
since it
> directly affects the behaviour of the flange to provide you a
leak tight
> joint (the code equation makes it clear). 20% of the causes that
leads to
> 80% of the flange leak (from what ive seen) are mostly due to
bolt
> tightening, bad fit-up (offsets), wrong gasket installed and
damage to the
> flange face. Check out b16.5.
>
> -----Original Message-----
> From: Rajesh_V_Balapure@ril.com
[mailto:Rajesh_V_Balapure@ril.com]
> Sent: 26 April, 2002 1:13 PM
> To: PipingDesign@yahoogroups.com
> Subject: [PipingDesign] Flange Facings.
>
>
> Dear All,
> I would like to know about flange
facings
> smoothness & gaskets .
> What is the significance of flange facing smoothness on the leak
tightness
> of the flange joints & selection of gaskets.For pressure rating
300#-600#
> ,which type of flange facing smoothness is recommended for weld
neck raised
> face flanges & which type of gaskets should be used for
particular
> smoothness.
>
> Regards,
>
> raj
Received on Sun May 05 01:10:00 2002
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