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=** Welding Glossary **=

** Occupational Health and Safety Regulations (1996) **
**Open-Circuit Voltage** - The voltage between the output terminals of the welding machine when no current is flowing in the welding circuit. (2)**Open-Circuit Voltage (OCV)** - As the name implies, no current is flowing in the circuit because the circuit is open. The voltage is impressed upon the circuit, however, so that when the circuit is completed, the current will flow immediately.

**Out-of-Position Weld** - Any weld where the work is not flat in front of the welder.

**Overhead Position** - The position in which, welding is performed from the underside of the joint.

**Overhead Weld** - An inverted weld where the pieces being joined are above the welder.

**Overlap** -The protrusion of weld metal beyond the toe, face, or root of the weld.


 * OZONE - ** Ozone (O3) is produced by ultraviolet light from the welding arc. Ozone is produced in greater quantities by gas metal arc welding (GMAW or short-arc), gas tungsten arc welding (GTAW or heli-arc), and plasma arc cutting. Ozone is a highly active form of oxygen and can cause great irritation to all mucous membranes. Symptoms of ozone exposure include headache, chest pain, and dryness of the upper respiratory tract. Excessive exposure can cause fluid in the lungs (pulmonary edema). Both nitrogen dioxide and ozone are thought to have long-term effects on the lungs.

Oxyacetylene torch shut down animation

**Oxyacetylene Use**

**[|Oxyacetylene]** ** [| Welding and Cutting ESBA]- ** this link leads to an Oxyacetylene Welding and Cutting Handbook

**Oxy-fuel Gas Welding (OFW)** is a welding processes which joins metals by heating the metal with a fuel gas mixed with pure oxygen. This process may be used with or without the use of filler metal. Molten metal from the base metal plate and the filler metal, mix in a common molten pool. When the welded metal cools, it will coalesce to form a complete metal, with properties similar to the original base metal.


 * Oxy-Fuel Safety**

Oxygen - steel cutting

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