Summary for galvanized pipe handrail flame Discussion
Flame shot out of galvanized pipe handrail when drilled is discussed as an unusual event with no obvious standard warning cited in the thread. John Rabbitt asked what could cause a flame to appear when a drill broke through a galvanized handrail pipe. One reply noted that a flame requires fuel, oxygen, and ignition, but said there was no obvious mechanism for a combustible gas forming inside galvanized pipe by accident; the responder suggested the flame color might help identify the fuel and mentioned hydrogen only as a possibility if acid had been introduced. Later, Ken Allan offered a more direct explanation: hydrogen had built up inside the sealed galvanized handrail and ignited when the hole was drilled, with the drill’s heat or a small spark providing enough energy for a hydrogen-oxygen mix to flash. The thread therefore presents differing views, with the later answer giving the clearest practical explanation.
Q. While drilling a hole in a galvanized pipe handrail, I had a flame shoot from the hole upon penetration. Have you heard of this before? What causes this to happen? Are there any warnings about this out there?
John Rabbitt
– Bellevue, Michigan, USA
June 19, 2012
A. After having galvanized thousands of tonnes of handrail pipe for many customers, have never heard of this before. For a flame there needs to be three things.
Fuel (presumably a gas in this case?)
Oxygen (air)
Ignition (your drill bit red hot?)
The air and possibly the drill are explainable, but what was the fuel?
What colour was the flame? That can be a clue to fuel type. For example a colourless almost invisible flame might be hydrogen? A sooty black flame might suggest acetylene … and so on.
There isn’t an obvious (to me) mechanism for producing a combustible gas inside a galvanized pipe by accident. If you put a strong acid in there (say hydrochloric) then the coating (zinc) would produce hydrogen. But you’d surely know if you added acid to the pipe?
Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK
June 22, 2012
A. Hydrogen build up inside the sealed galvanised handrail. Ignites when hole is drilled due to hydrogen & oxygen mix requiring very low input of energy to ignite (e.g. slight spark or perhaps the heat from the drilling)
Ken Allan
– Farnham,Surrey, UK
June 27, 2016