One solution could be to drop the pressure in two stages by using two control
valves or a fixed orifice and a control valve.
--- Paul Bowers <pbowers@pipingdesign.com> wrote:
> ____________________Forward Header_____________________
> Subject: Vibration from flashing valve
> Author: KV Ravichandran
> Date: 6/25/02 8:55 AM
>
> Hi,
> Can any one give guidelines for quelling vibrations from flashing control
> valve.
> This is my problem
> There is in one 8" Zirconium line carrying acetic acid/ catalyst from
> reactor
> to flash tank. At the flash tank side the line has one flashing control
> valve ,
> gate valve and a conical expander section of about 4.6m long where the pipe
> dia
> increases from 10" to 26" and connects to the flash tank eccentrically.The
> source of vibration is the flashing control valve (shear stream ball
> valve)which
> throttles from 26 bars to 2 bars. The liquid flow velocity is about 8.5m/s
> at
> the valve.Operating temperature of the line is 193 deg C.
> During the original design two phase flow and vibration was considered and
> the
> line is supported with TICO Vibration isolation pads and U bolt clamps.
>
> Now the platform from the flash tank as well as the structure supporting the
> piping near the flashing valve is vibrating.
>
> To have an idea about the magnitude of the vibration following is the latest
> measurements at the flashing valve.
> Fcy Velocity
> Hz mm/sec
> 4.405 1.418
> 8.811 1.049
> 13.22 .6426
> 22.03 .6278
> 48.46 1.876
>
> Thanks in advance
>
>
> Regards,
>
> K.V.RaviChandran
> Senior Piping Engineer
> Foster Wheeler Eastern Pte. Ltd.
>
>
>
>
>
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