Consult your msds and look at the ignition temps. It is not a matter of laxity.

I have seen different people rate the same area differently.  We have natural gas compression stations and take a class 1 div 2 approach that all the gas should be in the pipe, unless something unusual has happened.

Correct me if I’m wrong here, but you have a power generator station with bi-fuel engines, diesel and natural gas.  What percentage of the station has the same rating as your chemical plant?  I would think that just the pump house for the diesel and the compressor for the NG would be the only areas close to similar to your chemical plant.  Who defines your rating code?  We have DOT codes which define what pressure pipe and what equipment gives a specific rating.  If applicable code says no ignition sources, then it means no ignition sources.  Make sure you know the code and apply it to your plant.  If you try to apply your old methods to the new plant, you may have rules which are stricter than the code requires, and your bean counters will wonder why it is so expensive to operate this plant.  For example, is all the wiring in the generator plant to the same codes as your chemical plant?  In essence I think you should be asking what the code requires, not what other people are doing.

Good luck, I hate management forced decisions that have no field experience.  Of course I hate explosions also, especially when I'm in the general vicinity.  I also dislike it when employee morale or plant explosions affect my stock prices.  Boy, I am a really disagreeable person tonight.  

 

dwedel
Hotrod Big Engines!
For site policies and guidelines
see FAQ731-376

I have done some hazardous area classifications for power stations recently, both Gas turbines and bi fuel boilers, such as yours.

Looking firstly at the gas side of things.  The gas in the custody transfer station has quite clear hazardous area guidelines, that will be similar to chemical plants.  These will not stop when the gas gets into the power station.

For the diesel.  I believe that a pressurised diesel line has the potential to create a mist and therefore has a hazardous area.

However, the power stations have generally had well defined hazardous areas or at least the installation was compliant.  To answer your question about whether you take ignition sources away from people - On the last few power plants I have been on I have had to carry a gas detector to allow me to take photographs.

I have seen some small personal gas detectors like Tickle talked about.  Those would be nice.

dwedel
Hotrod Big Engines!
For site policies and guidelines
see FAQ731-376

Is a standard mobile phone / cell phone likely to ignite a natural gas leak?