Welding is a fabrication process whereby two or more parts are fused together by means of heat, pressure or both forming a join as the parts cool. Welding is usually used on metals and thermoplastics but can also be used on wood. 

Questions on the new CSA Standard

Here are a few changes that may impact workplaces (this is not the complete standard). For more details and information consult the CSA Standard.

1. Section 6.2.1 (b) When welders or welding operators are required to stand or lie on metal to perform their duties, protective insulation shall be used to keep the welder's or welding operator's body from direct contact with that metal. 

2. Section 6.2.1 (c) Welders or welding operators who are required to weld in damp conditions shall ensure that their welding gloves are kept dry throughout the welding operation. Rubber-soled work boots shall be worn and dry non-conductive materials shall be used to prevent direct or indirect contact with damp earth or work surfaces. Voltage-reducing devices should be used to reduce the risk of electric shock in these situations.

(d) Welders or welding operators shall not weld in wet or damp clothing.

(e) Welders working at above-ground levels are subject to falls to a greater extent than the average above-ground worker due to electric shock hazard as well as required worker positioning. Personal fall protection systems shall be provided that meet or exceed local jurisdiction requirements.

(f) Welding cables shall not be run through wet areas. Electrode holders, whip cables, and the welding power supply shall be kept dry. Underwater welding/cutting operations have special requirements; Clauses and shall apply to underwater welding /cutting.

(g) Water-cooled electrode holders and guns shall not be used if any water leaks exist.

(k) The welding machines that supply power to the arc shall always have the output electrically de-energized when electrodes are removed from gas tungsten arc, plasma welding, and plasma cutting electrode holders where high frequency " Arc Start " or " Continuous" modes are being used. For gas tungsten arc welding with direct current (dc) without the use of high frequency "Arc Start " or "Continuous" modes, the output may not need to be de-energized, provided that either of the following procedures are followed:

(i) an approved voltage-reducing device (VRD) is used; or

(ii) all of the following:

1. welders/ welding operators wear dry gloves and dielectric boots suitable for welding that are changed as required to ensure dryness;

2. welders/ welding operators u se insulated needle-nose pliers that are in a good state of repair for manipulating the tungsten electrode;

3. welding supervisors ensure that welders are following all other electric shock protection requirements; and

4. adequate training in changing electrodes is provided for welders/ welding operators.

(l) Welding cable shall be used within the voltage and current ratings intended.

(m) Welding machines left unattended shall be turned off.

(n) Jewelry, keys, and tools that might conduct current, heat up, or reflect light shall be removed before welding.

3. Section 6 .3.2 .1. 2 Portable engine-driven welding power sources shall be used in accordance with the Canadian Electrical Code, Part I. Tools and equipment fed from auxiliary power sources on welding equipment shall be protected by a Class A ground fault circuit interrupter (GFCI) device or shall be grounded by means of a primary ground rod or other suitable              ground connection. (See Table L.l of this Standard, and the Canadian Electrical Code, Part I.) 

Tools and appliances having double insulation protection or equivalent, and so marked, are not required to be bond to ground and may be used without GFCI protection. 

Note: Double-insulated tools (grinders, drills, etc.) are preferred. Because they do not require a ground conductor, they do not provide a path for welding current to flow. 

4. Section 6 .4 .5 Welding equipment not in use

When the welder or welding operator leaves the work area or stops for any appreciable time, the electrode holder shall be de-energized by turning off the welding machine. Unless equipped with a feature that automatically de-energizes the electrode holder when welding or gouging ceases even for a short time, the electrode or carbon rod shall be removed from the electrode holder when not in use. Tungsten electrodes shall be removed or retracted within holders. Electrodes in wire form in semi-automatic holders shall be retracted or cut off to remove the possibility of contact. Electrode holders shall be placed so that they cannot make electrical contact with persons, conducting objects, fuel, or compressed gas tanks. 

Note: Accidental contact with pressurized actuators containing combustible substances has caused explosions and serious burns to welders and nearby workers. Electrodes, and contact with grounded metal surfaces can induce stray welding currents, which are a fire and electric shock hazard.  

General questions on welding

Electromagnetic fields and high frequency voltages generated by the various types of welding equipment can cause interference with cardiac pacemakers or other implanted medical electromedical devices. People with metal implants in their body (including pacemakers, defibrillators, steel plates and pins, etc.) should be cautious of any effect on these devices. Persons with pacemakers should contact the manufacturer for direction, and persons with other metal implants should be aware that at least one case has been reported in which the welder experienced a burning sensation around the metal implant while using a high frequency welding process. 

Wearers of pacemakers or other electronic equipment vital to life should check with the life support manufacturers and their physician to determine whether a hazard exists. 

“Blank Flange” means a solid plate installed through the cross-section of a pipe, usually at a flanged connection

“Blanking or blinding” means the absolute closure of adjacent piping by fastening across its core a blank flange or blind flange that can withstand the maximum pressure of the adjacent piping.

“Blind flange” means a solid plate installed at the end of a pipe that has been physically disconnected from a piping system.

“Hot tapping” means a process of penetrating through the pressure‐containing barrier of a pipe or equipment that has not been totally isolated, depressurized, purged, and cleaned.

Hot tapping

279.1(1) Despite subsection 279(1), an employer who establishes a code of practice in accordance with subsection (2) may allow hot tapping to be undertaken on a pipe or equipment in service containing a flammable or explosive substance.

279.1(2) Before any hot tapping begins, an employer shall establish a code of practice that is specific to the type or class of hot tapping to be performed and is approved by an engineer.

279.1(3) A code of practice for hot tapping shall contain the following information:

(a) a description of the hot tapping to be performed;

(b) a description of any possible hazards that may affect the health or safety of employees;

(c) the procedures to be followed and the equipment to be used when hot tapping; and

(d) an emergency response procedure.

279.1(4) An employer shall ensure that

(a) only competent employees are permitted to perform hot tapping,

(b) the point in the pressure containing barrier to be hot tapped is checked and strong enough for the hot tapping to be performed safely,

(c) there is sufficient working space at the location at which the hot tapping is to be performed,

(d) exit routes are available and their locations are known by employees who perform the hottapping,

(e) employees wear appropriate personal protective equipment when hot tapping is performed,

(f) material being supplied to the pipe or equipment being hot tapped can be shut off immediately in an emergency,

(g) the hot tapping machine and accessories are of adequate design and capability for the work to be performed, and

(h) the pressure in the pipe or equipment being hot tapped is as low as possible during the hottapping.

Yes, it must be grounded with a ground rod or directly into a system that is already grounded to earth (Building already grounded, for example). 

A voltage reduction device (VRD) is a hazard reduction device that lowers the welder’s open-circuit voltage (OCV) to prevent electric shock from welding current. A VRD is often combined with stick welding machines used in damp environments. 

A VRD can be a separate device that attaches to the welding cable connectors, permanently placed into the welder, or embedded into the welder 

When working in wet and damp environment conditions.


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