Hastelloy Solenoid Valve, Chlorine gas Service

[snob]

I am looking for 4 only 1/4" solenoid valves.Screwed. 110V Ac. 2 way normally closed in hastelloy material for use on Chlorine gas service @ 60 kPa, ambient temperature. this is on an anilizer. The solenoid is placed within the housing of the anilizer and this area is purged with nitrogen. My customer has been supplied PVDF bodied, Teflon internal solenoid valves and these have not worked.

do you know anyone who may be able to help.

Kind Regards


Snob !

 

[hacksaw]

s~

you need to be real cautious about replacing soln. valves in analysers.

there are many issues that go beyond corrosion etc.

Hast. C soln. valves are not common,that is probably why non-metallics were used.

are the valves in a heated enclosure?
what are the shut-off leakage requirements?
are these "sample" switching valves?
how clean is the gas going through the valves?

 

[snob]

Hacksaw,

The solenoid is used within the anilizer with the process temp around 35 deg c. The chlorine is a mix of 86% Chlorine, 6% HCL and the remainder is Oxygen. The anilizer measures the amount of oxygen within the Chlorine.

The solenoid is the main sample isolation valve. The chamber is heated to ensure that no Chlorine forms and creates droplets.

Hope all this helps. No information available at this stage with regard the leakage class.

Thanks for your help.

Kind Regards

Snob

 

[hacksaw]

S~

Most chorine sample systems are operated under negative pressure (sample is drawn through the analyser). Does the 60 kPa refer to negative gage pressure?

What is the problem with the existing valves?

coil failures?
valve internals sticking or plugging?

too many questions to address in this forum what's a good way to contact you?

 

[hacksaw]

S~

after some thought, your analyzer system can run on positive pressure but you should have a "vaporizing regulator" in the system that drops the pressure. It may be heated to minimize mist formation, downstream you should have a coalescing filter to remove any mist or solids.

The soln valves you are using have very tight pressure limits. 65kPa may be to much for them to operate against. Most gas analyzers work great on a few kPa as long as they have adequate flow (a few cc/min inside the cabinet).

If the spent sample is vented to a 0 kPa system, then you need to install a needle valve in the heated cabinet to reduce the pressure and set the flow.

There may be one there already. If so adjust it. It may be located on a sample flow rotameter. Set it. You may also have a sample back-pressure regulator down stream of the analyzer: check it's setting.


If the max. sample pressure to the analyzer is below the pressure of the sample return point in the process, then you need to re-compress it.


Your analyzer reading will depend on the pressure of the gases being tested and those being used for calibration. So pay careful attention to the pressure balance.

 

[snob]

I'm on markp@pipact.com.au

Thanks

Mark Pech

 

[snob]

Hacksaw,

thanks for your advise. I will pass this onto my customer. This engineer can check this detail. The actual design comes from a joint venture partner in the states. Altjough , they are useing Hastelloy valves.

Once again.

Thanks