Stack Gas Analysers And Electrical Heat Trace Line- Ex Proof

You might consider steam heat tracing instead, if steam is available in your facility. Heated water (possibly with additives) might also work.

analyser is to be installed in refinery and steam is available but it was observed in past that steam tracing is not as effective as EHT due to varying pressures of steam and temp variation. Is any ex-proof analyser available so that we can install on stack deck itself??

Installation in explosive/flammable areas varies from country to country in terms of what is required to meet the electrical/safety codes.

Meeting ex-proof may be complicated by the fact that a gas sample must be brought into the box. I'm not sure if it is possible to meet ex-proof in this case. If it is, then it does not matter whether a vendor make an ex-proof model or not, you could always just put the analyzers in your own approved ex-proof enclosure, if the code allows.

Another approach would be to put the analyzer in a purged or pressurized enclosure.

It really depends on what the local electrical code allows. When I was involved with such things, what was required in the US would be totally illegal in Europe and vice- versa. As an example (and going from memory), in the US it was perfectly acceptable to put a general purpose device in a purged enclosure to meet a hazardous location requirements, but statically pressurized boxes were not allowed. In Europe, pressurized enclosures were used, purged enclosures were not allowed. I believe that later regulations in Europe no longer allowed simply using an approved pressurized enclosure, the entire device had to be ATEX approved.