Non sparking belt guard 2

[acmp]

I have been asked to provide a non sparking belt guard. Someone told me to make it out of Aluminium. Do I need to use Aluminium fasteners on the guard as well? I worry Aluminium is too soft to hold things together. Can I use regular steel fasteners? Thanks.

 

[Artisi]

What / where is the application.

"Non-sparking" is a common term used in underground mining - which means anything that can produce a spark of sufficient intensity to ignite gas is forbidden underground - this include aluminium. So if it's an underground application - aluminium can not be used.

Naresuan University
Phitsanulok
Thailand

 

[ScottyUK]

What about using one of the engineering polymers such as polycarbonate to make the guard? What is the guard for? Preventing inadvertant personnel contact, or withstanding heavy vehicle impact? Insufficient information at present!


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I don't suffer from insanity. I enjoy it...

 

[ct140]

Hello,
Brass and bronze are suitable no-sparking materials, so I would recommend brass, since this is readily available as sheet metal. Also it has the advantage above polymers that it can handle better external load when you chose sufficient wall thickness, depending upon the size of the guard. In customer spec's I see usually 100 kgs as external load to withstand. Hope this helps, regards, ct140

 

[timbones]

Aluminum is definately non-sparking, but depending on site requirements may not be permitted. Brass/bronze are standard as well.

I would be more worried about the non-sparking of the belt itself.

 

[sprintcar]

Try "Orange Peel" guards - these are form fit plastic w/ warning labels, etc. Plenty of catalog sizes. I think Falk owns the company now.
Check some of the Stainless Steel alloys - that will give you strength and corrosion resistance

Timing has an awful lot to do with the outcome of a rain dance.

 

[jet1749]

Aluminium can spark if in contact with rusty carbon steel (drive pullies in your application?)hence we do not use it for guards in zoned area's. Brass sheeting makes good non sparking guards if they have adequate corrosion resistance in the proposed area. Have seen Brass used for ATEX rated applications under DSEAR regs. Belts should be ok if they are FRAS rated (fire resistant/anti-static)

 

[Artisi]

The statement by timbones "Aluminum is definately non-sparking" is incorrect, as pointed out by myself and confirmed by jet1749, aluminium is NOT non-sparking - this is an important safety issue for hazardous areas which everyone involved in pumping equipment needs to be aware of.

Naresuan University
Phitsanulok
Thailand

 

[timbones]

In light of no clear evidence that I can find that aluminum is a sparking or non-sparking material in all situations, I will err on the side of caution and concede it might be a sparking material.

But I think more explanation is needed as so many things are made of aluminum and are claimed to be non-sparking. Often when I get bids from vendors for equipment in hazardous areas they have specified aluminum coupling guards as non-sparking (I have never accepted them because aluminum is not allowed in the plants I work on for other reasons). Certainly if you bang two pieces of aluminum together, you will be there all week trying to make a spark. If you bang aluminum to a piece of rusty carbon steel, perhaps you will get a spark from some sort of chemical reaction, I can't be sure. But then, I can't confirm that if you bang brass on every known material you won't create a spark from any of them either.

Tim

 

[ScottyUK]

Tim,

Aluminium is actually a very reactive metal. This should be apparent from its placing in the Periodic Table. The property of aluminium which disguises this reactive nature is the highly tenacious and very thin layer of aluminium oxide which forms almost immediately when raw aluminium is exposed to the atmosphere.

Mechanical damage from, say, contact with a rotating iron drive pulley would expose fresh aluminium in its reactive state. Add a little iron oxide in the form of rust and some frictional heating and you have the makings of the thermite process, a highly exothermic reaction between iron oxide and aluminium which results in pure iron and aluminium oxide as an end product. It is often used as the heat source to weld joints in rail tracks.

Many non-sparking tools are made from one of the bronze alloys, ironically often one bearing aluminium, or a beryllium copper alloy, both of which have good strength and low sparking capability.

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I don't suffer from insanity. I enjoy it...

 

[Artisi]

ScottyUK a good post - worth a star - and saved me looking up the info.

Naresuan University
Phitsanulok
Thailand

 

[timbones]

Very intersting and clears up a lot of confusion and a common misconception. Thanks! It does make me worry a bit about the aluminum installed in hazardous areas that engineers have assumed is non-sparking.

 

[jet1749]

Aluminium for any use is not allowed in our hazardous areas, examples are access ladders, scaffold tubing, insulation/lagging sheets etc. Quite frightening when you consider the possible uses of a very versatile material!

 

[ScottyUK]

Artisi,

Thanks!

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I don't suffer from insanity. I enjoy it...

 

[Artisi]

Even aluminium food containers (the standard TV dinner type)are banned in most underground mines.

Naresuan University
Phitsanulok
Thailand