Tutorial: Engineering technology Topic: Flame welding Prepared by : Ing. Josef Martinák st. Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/ je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.
oxygenMixing jet Flammable gasPressure jet Burner nozzleweldment Welding wire Cap-NutOxygen valve handle Acetylene valve Mixing pipe Fitting with valves Reduction valve Identifying oxygen colors – white and blue Colourful acetylene labelling – chesnut brown (SRN), white (ČR) Gas inputs Pressure bottles Valves against backward flashing Labeling N – new colorful labeling in SRN valid from 1st July 2006
Oxygen O 2 – without colour, taste, smell, non-toxic, encourages burning Acetylene C 2 H 2 – flammable, high heating value, it explodes with oxygen Hydrogen H 2 – colourless, nontoxic, it makes explosive mixture with oxygen Propane, butane – nontoxic, it makes explosive mixture with air and oxygen
gas Bottle neck bottle Cone of hard rubber Bottom spindle Valve unit Fibre ring Upper spindle Manual wheel Upper spindle nutspring Valve nut Sleeve top Fibre fitting Connection to reduction valve Socket ring
White painting Reduction valve Porous mass aceto ne 2 Acetylene bottle
Inside gauge Bottle cap Safety valve Pressure bottle Regulation pressure bolt To burner Gas shut-off Outside gauge
Oxygen pressure – we set it at closed valve Working pressure for welding is 0,3 – 0,4 MPa Acetylene pressure – we set it at closed burner valve – probably 30 – 40 kPa Working pressure can not be increased over 0,15 MPa Ignition temperature is about 335°C Safety valve – protects reduction valve against high pressure Protection against burning – there is net of copper wire between bottle valve and reduction valve, it must be near oxygen For oxygen For acetylene
Low-pressure (injector) High-pressure (mixing) injectoroxygen acetylene Mixing chamber oxygen acetylene
Neutral flame – ratio of oxygen to acetylene is 1:1 Welding cone is white, usage – steel, copper, zinc, lead, some kinds of bronze Welding cone Welding material nosepipe
Weld is brittle and hard Aluminium, cast iron and magnesium welding Acetylene surplus
Suitable for brass welding, some kinds of bronze, for surface steel hardening by flame Bluish shortened welding cone
What materials do we weld using neutral flame?
DILLINGER, Josef. A KOL. Moderní strojírenství pro školu i praxi. 1. Praha: Europa- Sobotáles, ISBN M. HLUCHÝ, J. KOLOUCH, R. PAŇÁK. Strojírenská technologie II Translation: JANATA, Petr. Handy slovník technický anglicko-český a česko-anglický. Plzeň: Nakladatelství Fraus, ISBN Lingea LEXIKON 5, Technický slovník anglicko-český a česko-anglický