Flow meter used in H2S gas service

Hi, What type of instrument is best suited to measure H2S gas flow? Our understanding is that Vortex meters and the standard orifice plate + DP
transmitters have been tried, but found to be unreliable (plugged impulse lines for DP installation).
If anyone is aware of an installation where the installed instrument is performing satisfactorily, please let me know. Thanks and regards, Raj Sreenevasan
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We use orifice plates all over the place with sour natural gas (8 - 12% sour). We use close coupled manifolds by Anderson Greenwood and then bolt on a Rosemount DP transmitter with very few troubles. Don't know where you are, but on the wetter streams we will also run a bit of steam tracing underneath the transmitter and manifold, and an a custom build insulated blanket to go around the transmitter. We use this same arrangement on sour liquids with success as well. Just make sure you're coming off the side of the pipe (9:00 or 3:00).
In our sulfur plant we have low pressure acid gas (75% H2S 25% CO2) and we use a regulator with 2 rotometers at the transmitter, and purge back through the sensing lines. If the rotometer flows are constant, it shouldn't affect the flow measurement.
Curtis
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Curtis, The application I am talking about, H2S gas is produced by burning Sulphur with Hydrogen in a reactor. The plugging occurs due to the presence of Sulphur particles. Any how we will trial the purging arrangement. Thanks for the suggestion. Regards, Raj

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Wedge meter or venturi with 3" diaphragm seals with purge connections if required in the future. Use the DCS or control system to look for an absence of pressure fluctuations (plugging).
Also make sure you specify gold plated diaphragms due to possible Hydrogen Permeation.
--

PuNx



"Raj Sreenevasan" <Raj snipped-for-privacy@bigpond.com> wrote in message
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Sounds like good advice to me.
Walter.

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