help! We need to make our product nonsparking. 1

[penfold07]

Hi,
One of our customers has enquired if it is possible to produce intrinsically safe/nonsparking versions of our tools, which are hand operated hydraulic and mechanical spreading and lifting wedges/jacks, made mostly out of forged alloy steel; My initial stabs in the dark have suggested in no particular order, Xylan(fluoropolymer) coating, copper alloy plating, and possibly a PVD coating of some kind. Is there any data available about PVD coatings making steel parts nonsparking?

One of the biggest problems I have encountered so far is I cannot find a national or industry standard defining what constitutes a nonsparking material/finish; can anyone enlighten me? The tools are curently sold with a xylan coating, but with that or cuprous alloy plating, there are concerns about durability and/or abrasion resistance. Can you provide any advice?

cheers,
David

 

[JTreglio]

I guess what you need is a hard, non-conducting film to prevent sparking. Zirconium oxide is one possibility. It's deposited on turbine blades as a thermal barrier by both plasma (thermal) spray and PVD. Aluminum oxide is another possible coating. Both coatings are relatively hard and wear resistant if deposited correctly.

Jim Treglio
Tribo Coating LLC

 

[Compositepro]

All non-sparking tools I've seen are made of solid brass. I doubt that thin coatings would be effective. Hardness and low thermal conductivity cotribute to creating sparks. Sparks are caused by impact or abrasion that creates hot particles of metal that ignite in air. Soft metals do not easily make small partcles and high thermal conductivity keeps the surface temperature dowm when heat is created by impact or friction.

 

[fasele]

i have a similar problem. we have studied various metals to know what are the specifications of non-sparking metals and how we can select them. in another word, what make a metal to be non-sparking?do they have specific characters? i found some reasons such as tensile strength and thermal conductivity.but are these the only reasons of being non-sparking? any ideas?

 

[tomwalz]

We had a similar request several years ago. We declined to bid because we couldn’t build tools that worked well and would never produce a spark.

Our big problem was the same as yours in that we couldn’t find a standard for non-sparking.

Our attorney’s advice was that we couldn’t produce a tool that could produce a spark no matter what the conditions of use, wear or abuse were and still call it non-sparking.

That seemed to eliminate any sort of coating we could find.


Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

 

[israelkk]

MIL-W-23514A WRHENCH, SPANNER, ADJUSTABLE HOOK: NONSPARKING
AND NONMAGNETIC askd specifically for non ferrous alloys.

You can get it at

http://assist.daps.dla.mil/docimages/0004/75/47/23514A.PD0

 

[kenvlach]

There is considerable risk (functional & legal) in using coated steel.

That's some test (using gasoline vapors) in MIL-W-23514A!

Aluminum, brass, bronze, maybe Monel are typically used. Ampco has a lot of non-sparking alloys & tools.
"Government Requirements & Approvals
Non-Sparking, Non-Magnetic, Corrosion-Resistant Tools and Tool Kits
Recommended for use in hazardous environments where flammable or combustible vapors, liquids, dusts or residues are present.

USFA/FEMA (U.S. Fire Administration / Federal Emergency Management Agency) "Hazardous Materials Response Technology Assessment" states, "Ordinary hand tools are usually made of steel, which can cause sparks if struck, scraped, or dropped which can be disastrous in an explosive atmosphere. Tools used in a hazardous materials incident MUST be constructed of non-sparking, non-ferrous, non-magnetic corrosion resistant metals."

OSHA (Occupational Safety & Health Administration) document "Hand and Power Tools" states, "Iron or steel hand tools may produce sparks that can be an ignition source around flammable substances. Where this hazard exists, spark-resistant tools should be used..."

Ampco Non-Sparking, Non-Magnetic and Corrosion-Resistant Hand Tools conform to Federal, GSA, Military, as well as other international standards. Non-sparking or intrinsically safe tools are required and/or recommended many Federal agencies including OSHA, the Department of Energy (DOE), the National Fire Protection Association (NFPA), and the Mine Safety and Health Administration (MSHA), National Institute for Occupational Safety & Health (NIOSH) and Supervisor of Shipbuilding & Repair (SUPSHIP) to name a few."

http://www.ampcosafetytools.com/approvals.htm