Welding galvanized steel fittings on steel pipes

[testingpump]

I know that welding galvanized fitting with steel fitting is not recommended , can you tell me why ?

 

[BigInch]

I believe its is because zinc screws up the weld.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[pennpiper]

Welding galvanized pipe shoes and other miscellanous objects to pipe has been done for many, many years.

The main risk in doing this, is the gas that is created when the zink is burned during the welding process. This gas can be life threatening.

The zink coating needs to be ground off to create a weld lane. It would also be wise to have an air flow that blow any stray fumes away from the welder.

 

[moltenmetal]

The risk of zinc oxide fume exposure to the welder is secondary to the risk of zinc embrittlement and porosity induced by zinc in the weldment.

Both the OD and ID need to be ground to completely remove zinc before welding.

Be aware that a lot of galvanized fittings are ductile iron rather than carbon steel...

 

[RossABQ]

moltenmetal, aren't they actually malleable iron, not ductile?

The whole idea of welding threaded components kind of bothers me.

 

[Zapster]

For your amusement take a look at “Welding Health Hazards,” on the OSHA site:

http://www.osha.gov/doc/outreachtraining/htmlfiles/weldhlth.html

If you read through the paragraph labeled Zink, the last sentence is very humorous in the context of the information.

 

[RossABQ]

I can't believe someone snuck that in!

 

[BigInch]

"The subject can then appear to be more susceptible to the onset of this condition on Mondays or on weekdays following a holiday than they are on other days."

What does that NOT include?

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[moltenmetal]

RossABQ- yep, they're MI, not DI. Conclusion's the same, though- do not weld!

 

[kenvlach]

What's the problem or humor with the OSHA language?
Of course, the onset of 'metal fever' is more likely on Monday. Tues-Friday, the welder has a continuing case which ameliorates over the weekend.

That page is obsolete. In 1999, the subject list was broadened to: Antimony, Arsenic, Barium, Beryllium Cadmium, Chromium, Cobalt, Copper, Lead, Manganese, Mercury, Nickel, Ozone, Selenium, Silver, Vanadium.

http://www.aws.org/technical/facts/Z49.1-1999-all.pdf

See current standard Ventilation and protection in welding, cutting and heating. - 1915.51

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10229

Also, in 2006, OSHA issued new, much lower permissible exposure limits (PELs) for hexavalent chromium (which is created in arcs/plasmas from stainless steel, chromium plating & other Cr-containing materials.

http://www.osha.gov/SLTC/hexavalentchromium/

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=13116