HYDROCARBON ANALYZER - HAZARDOUS AREA CLASSIFICATION

[bobziva]

Hydrocarbon Analyzer is provided to be installed in special room for the monitoring of hydrocarbon contamination. That room is potential hazardous area, and Owner wants to discuss about that.
I used to read many prospects / catalogues about hydrocarbon analyzer and manufacturer always stops the process if something wrong, but never provides information about their product as hazardous area device.
Thank you for any info / article about that.

 

[Kiribanda]

Hi bobziva,

API 500/ 505 & IEC 60079 don’t provide direct information about relevant classification.

From your information it is possible to classify the room with reduced ventilation as Class 1, Zone 1 or Class 1, Division 1 with reasonable justification.

Normally modern Hydrocarbon Analyzer Units (similar to Oxygen Analyzers) are instruments with low voltage/ low power consumption. Hence it is advisable to use equipment with energy limitation techniques. Therefore the units should be of the type “Intrinsically Safe Apparatus – Ex ia/ib “.

Regards!
Kiribanda

 

[jbartos]

Suggestion: Normally, analyzing, indicating, recording, etc. instruments are installed outside hazardous areas since installation of small conduits, conductors and pipes is inexpensive.
To install analyzer in hazardous area will have the following drawbacks:
1. Troubleshooting, calibration, etc. will require to de-energize the equipment
2. The room hazardous area may have to be clean up to non-hazardous area, since there may be charged capacitors that may produce an electric spark.
3. There may also be static electricity
4. Installation outside the hazardous area is usually less expensive

 

[bobziva]

Kiribanda and jbartos.
Thank you for comments.
Probably you didn't understand my question.
(1) area provided for installation of analyzer is non-hazard area but
(2) as soon as analyzer is instaled there including a pipe with the liquids containing hydrocarbons, that area becomes
hazardous area because of flammable gas ( hydrocarbons)

 

[bobziva]

Dear Sirs,
Hydrocarbon Analyzer is provided to be installed in special room for the monitoring of hydrocarbon contamination.
We have to make order for that Hydrocarbon Analyzer, but we have a couple questions :
(1) Hydrocarbon Analyzers, available on the market,are provided for permanent operation or not ?
Owner prefers permanent testing operation. What do you know about that ? What is your suggestion about maintenance, how to minimize maintenance ? ( cleaning of the pipes etc.)
Are you suggesting Time-Relay for the control of testing operation from time to time, or maybe you have a better solution. We are trying to minimize maintenance.
Are you suggesting ventilation ? ( fans)
(2) Area provided for installation of the Hydrocarbon Analyzer is non-hazard area but as soon as analyzer
is installed there that area becomes hazardous area because of flammable gas inside a pipes ( hydrocarbons).
Did you provide Hydrocarbon Analyzer as equipment for Hazardous Classification Area. ?
Sincerely,
Bobziva

 

[duck0601]

Bobziva,

What range of hydrocarbon contamination are you looking at, and is it Gas or Liquid.

 

[jbartos]

Suggestion: The analyzer manufacturers may have application notes that are normally used for the analyzer applications. The clue may be in the analyzer sensing or sampling portions of the gas or liquid, and where these are located.

 

[PowerEnrg]

Having flammable liquids in an a pipe does not automatically classify the area as hazzardous. If that were the case then my house which has uses hydrocarbons (#2 Fuel Oil and Propane) would be classified as hazzardous.

Consult the National Electrical Code for definition of when an area is considered hazzardous or not.

You will find that the operative word there is "likelihood" of gas vapors being present.

Also, check with the owners insurance company, code issues aside, they usually have the final say.

 

[prk]

because of various connection of tubing etc the area certainly do not remain safa or unclassified , once the analyser is installed. for all switching operations the solinoid valves in general are intrincally safe but other parts have to be certified safe for hazardas area. the room can be provided with some purging so that the liklyhood of presence of hydrocarbon is minimised to a great extend. but all of it depends that what type of industry it is being used in ans what kind of risk/hazard are involved in surrounding areas, whatever it may be there are suitable products in the market for almost all the areas.

 

[jsummerfield]

It helps to know what hydrocarbons are being measured and some specifics about the analyzer such as sample flow rate, etc.? You mention flammable gas. Is the sample liquid or gas?

Install shutdown valves on the sample outside the building. This can be a solenoid valve or a solenoid that vents the air from a pneumatically actuated valve. The solenoid must be suitable for the area classification. However in the US this is likely Class I Division 2 for many hydrocarbon liquids and not intrinsically safe.

Some analyzer sample handling systems can be separated from the electronic components. Such sample systems can be located outside in a manner that only small tubing enters the building for the sample.

Excess flow valves exist that can limit the volume in the event of a rupture. This is especially applicable to gas samples.

Not all hydrocarbon liquids require hazardous area classification. For example the flash point of Diesel may be outside the requirements for hazardous classification.

Depending pon the design and effluent venting issues, consider installing the analyzer in a fume hood. The special room could include special ventilation or wiring per the appropriate NEC article 500 requirements.

John