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smpsmp45
25-07-2008, 08:20 AM
Is anyone aware on suppliers of Flame Proof Light Fittings for Cold store. Especialy Bulk Head fittings with 120W light Bulb.

alphi
25-07-2008, 03:47 PM
Amigo,
try appleton brands. there were a lot of suppliers of this kind but for safety purposes on hazards, you may try to use this brands.

For Bulk headd fittings....are you describing for HID lamp fixtures?

smpsmp45
26-07-2008, 01:18 PM
Many thanks., I shall check up with this company. Bulk Head fittings are Similar to Halide Lamp fittings.

nevgee
26-07-2008, 08:11 PM
This site might be helpful

http://www.hazardexonthenet.net/productdisplay/productdisplay.html

nevgee
26-07-2008, 08:19 PM
here's another
http://www.r-stahl.com/start.html

and another
http://www.walsall-ltd.com/Main/Splash.aspx?SessionKey=&PageID=20

US Iceman
26-07-2008, 10:53 PM
I'm curious abou the terminology used here. Is flame-proof the same for explosion-proof?

IF so, why are you required to do this?

Thanks.

nevgee
26-07-2008, 11:30 PM
Flame proof is the old English terminology for explosion proof. Used incorrectly I suppose. The term flameproof was an expression indicating that any explosion within the enclosure, motor housing etc would be released through gaps,called flame paths. These flame paths were the joints at end shields, shaft bearing housings, and joint box lids.
The flame paths were machined to set tollerances and had specific lengths so that any flame that would pass along the path would be cooled sufficiently enough to reduce its temperature so as not to be hot enough to ignite an exposive gas or dust.

Whereas explosion proof is just that .. any explosion within the enclosure is contained within it.

The US definitions were / are some what very different concept and not compatible with the old BASEEFA (british) standards.

I'm very rusty with the current standards but there are now different ideologies, flameproof, was particulary a concept used in the coal mining industry.

Other concepts use the principles of "non sparking" limited temeratures ect. But the advent of EU Directives "ATmosphere EXplosive" is an attempt to harmonise the standards ...it's become a bit of a minefield ...BOOM!

Hope that helps clear the mud.

US Iceman
26-07-2008, 11:51 PM
Thanks nevgee, that helps. However, my question still stands; Are these fittings/construction type mandatory for ammonia refrigeration systems? In an ammonia facility for storage or production I could see a different requirement due to the process involved.

In the US the locations of electrical equipment is defined by a classification for that specific area and the prevalent atmosphere that may exist. I'm rusty on this also...

nevgee
27-07-2008, 12:51 AM
I don't recall too fully the implications of ammonia systems. Only ever did one design and that was a long time ago ...however, ammonia is explosive at a particular concentration with air ...not sure but 15% seems familliar.
So maybe there is some requirement to use explosion proof kit for the essentials like lighting and extract fans ...otherwise I don't know.

nevgee
27-07-2008, 01:07 AM
Here ya go ...

Ammonia forms a flammable mixture with air at concentrations between 16 and 25% v/v.

Apparently due to the nature of ammonia and it's low level of tollerance ..it's assumed that action will be taken well before the LEL is ever reached. Therefore only lghting and extract equipment really needs to be suitable for explosive atmospheres and in this cas Zone2 and type "n" rating is suitable. Type "n" is non sparking kit. There are temperature limits of course.

This is an extract from the British Health and Safety Executive a link is pasted below:

Option 2 - Detection of leaks by personnel or gas detectors
ln this approach, non-explosion protected electrical apparatus, with qualifications, may be used in combination with a readily available means of isolating the electricity supply. The method of achieving the latter can be accomplished either automatically after detection of a leakage by a gas detector system, or manually after a leakage has been detected by personnel. The use of these techniques as a first line of defence is limited to applications solely involving ammonia in refrigeration plants. This approach is considered acceptable provided that the general principles outlined in paras 10-17 are followed and that sufficient account is taken of paras 5-9.


http://www.hse.gov.uk/lau/lacs/31-1.htm

happy reading:D

US Iceman
27-07-2008, 03:41 AM
That is similar to our requirements. The mixture flammability range is though dependent on a constant ignition source temperature. Ammonia won't sustain a flame, but the oil will.

I think it's also important to note the use of the term explosive. While this term is used a lot, the best information I have heard about says the propagation is more along the lines of a deflagration, rather than an explosion.

There is not as much energy generated in ammonia events as other truly flammable fluids that would be self-propagating.

smpsmp45
27-07-2008, 08:06 AM
Dear nevgee,

It seems you are working in the same field as you seem to know a lot on this subject. many a times we follow the specifications blindly

nevgee
27-07-2008, 10:13 AM
SMPSMP45

Did you see these links

http://www.hazardexonthenet.net/prod...ctdisplay.html (http://www.hazardexonthenet.net/productdisplay/productdisplay.html)

here's another
http://www.r-stahl.com/start.html (http://www.r-stahl.com/start.html)

and another
http://www.walsall-ltd.com/Main/Spla...Key=&PageID=20 (http://www.walsall-ltd.com/Main/Splash.aspx?SessionKey=&PageID=20)