Is this similar to a double block and bleed arrangement? or is it
similar to the arrangement in the PSV?
- In PipingDesign@yahoogroups.com, "Paul Bowers" <pbowers@p...>
wrote:
> I think to do an in-service internals replacement you'd need a
duplex setup
> such as I've seen with metered city water supply systems, but my
memory is
> fuzzy on this. It looks like there might be a spec
misunderstanding or
> confusing writing as Steve suggests.
>
> Paul
>
>
> ----- Original Message -----
> From: "Steve McKenzie" <mechproj@x...>
> To: <PipingDesign@yahoogroups.com>
> Sent: Wednesday, January 07, 2004 5:18 AM
> Subject: RE: [Man.Distr]Re: [PipingDesign] Swing Check Valve
>
>
> > Hi Sajit
> >
> > I have never seen a swing check that permits "in service swing
> replacement",
> > and I doubt if there is any such thing as it would need two
additional
> > sealing arrangements (valves) plus body drain. Perhaps the spec
writer
> means
> > "in-line disc and body seat replacement"; i.e. it is not
necessary to
> remove
> > the valve from the pipeline in order to replace the
sealing/wearing
> > components. Also I am not aware of any part of a swing check
valve called
> a
> > swing. You may wish to query this with the spec writer.
> >
> > A note of caution; most swing checks have a hinge pin that is
removed from
> > the side of the body. Side clearance is required to remove the
spindle,
> > otherwise the body may need to be removed from the pipeline.
> >
> > Cheers
> >
> > Steve McKenzie
> >
> >
> >
> > -----Original Message-----
> > From: Sajit Viswan [mailto:sviswan@t...]
> > Sent: Wednesday, January 07, 2004 6:59 PM
> > To: PipingDesign@yahoogroups.com
> > Subject: RE: [Man.Distr]Re: [PipingDesign] Swing Check Valve
> >
> >
> > The PID calls for this requirement. "Full bore check valve with
external
> arm
> > shall be top entry and allow swing replacement in service". The
line size
> is
> > 18". There are block valves shown across it with a drain d/s. I
believe
> that
> > this does not imply that the block valves have to be closed and
then the
> > swing taken out for maintenance, which then is an ordinary check
valve
> with
> > only an external arm or a dash-pot.
> >
> > Sajit
> >
> > -----Original Message-----
> > From: rajendra bajikar [mailto:rajendrabajikar@y...]
> > Sent: Wednesday, January 07, 2004 9:30 AM
> > To: PipingDesign@yahoogroups.com
> > Subject: [Man.Distr]Re: [PipingDesign] Swing Check Valve
> >
> >
> > Dear Sajit,
> > Is this a one time problem or regular? What is the line size?
Could you
> > please elaborate?
> > Regards,
> > Rajendra Bajikar.
> >
> > Sajit Viswan <sviswan@t...> wrote:
> > Is there a check valve that allows swing replacement while in
service?
Received on Tue Sep 13 02:20:00 2005