EXPLOSION PROOF EQUIPMENT REQUIRMENTS

[NADOR123]

Hi everyone,

I need to find out if any code or standards require that all motors of the equipment at the sewage treatment plants process area have to be explosion proof motors.

 

[gerhardl]

Where are your located? For Europe (EU) and Scandinavia the answer is no.

But: There will always be a local authority (European rules) that will/can inspect any plant or process where there is a possible danger of explosion.

Your clue is to check what explosion areas the plant has, if any, and what grade. If this is not decided yet, this has to be decided according to existing rules and parctise, and recognised by local inspectors.

In Europe local inspectors can stop your plant if Ex. protection is not satisfactorily done.

I know about one instance in a waste depot where a smaller control hut exploded when the lighting switch was operated, because of uncontrolled methane gas leakage from the ground during the night..

If there is a probability of fumes or gases assembling it will be sensible to use both gas detectors and ex- motors, and have an extra look at natural and forced venting.

I cannot see, however, that ex protecting equipment should be necessary all over for a complete, satisfactorily vented, normal waste-water treatment plant. The plant would normally be constructed to avoid smell and uncontrolled escaping gases.

 

[Ussuri]

If in the UK, you need to look at the DSEAR Regulations (Dangerous Substances and Explosive Atmospheres Regulations)

 

[NADOR123]

I am in New York State , USA

 

[civilperson]

Not if your equipment is above grade and well ventilated, (not in a pit or contained with walls surrounding sewerage fluids).

 

[bimr]

The preliminary treatment area (including influent pumping equipment) and sludge digestion area will generally be considered hazardous areas requiring explosion proof equipment.

Refer to:

NFPA 820: Standard for Fire Protection in Wastewater Treatment and Collection Facilities

http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=820&cookie_test=1

 

[Unotec]

I'd also look into the electrical code. I am not familiar with the US, but in Canada this is typically very clear.

 

[bimr]

The NFPA is actually the group responsible for writing the electrical code.

 

[NADOR123]

Hi everyone

Are the pumps/equipments in open air sewage treatment plant tanks have to be explosion proof and what is the code specifing that in USA. Is the tank area considered class 1 division 1 or 2.

Thanks
Nader - NEW YORK

 

[bimr]

NADOR123,

Download the NFPA document. It is free at this site:

http://www.normas.com/NFPA/PAGES/NFPA-0820(03).html

You can look up the recommended guideline in that NFPA document. The NFPA document will be valid if adopted by the local building department. Otherwise, the standard is not a requirement of the building code and it is just a recommended standard.

An open air situation at a treatment plant would probably be unclassified. However, you have not provided enough information to make a definitive statement.