Page 66 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

The City & Guilds Textbook: Plumbing Book 1

Oxyacetylene equipment safety checks

Before using welding equipment, it is wise to check its condition and operation.
As well as normal equipment and workplace safety checks, there are specific
procedures for oxyacetylene.

You should check that:
● flashback arresters are present in both oxygen and acetylene lines
● the hoses are the correct colour, with no sign of wear or damage, as short as
possible and not taped together
● the regulators are the correct type for the gas being used
● a bottle key is in each bottle
● the bottles are securely fastened by chains to the bottle trolley and the
trolley is in good condition.
It is recommended that oxyacetylene equipment be checked at least annually.
Regulators should be taken out of service after five years. Flashback arresters
should be checked regularly in line with the manufacturer’s instructions; it may
be necessary to replace some types if flashback has occurred.

Assembling and purging the oxyacetylene equipment

Before assembling the equipment, you must:
● check that all cylinders have been handled properly
● check that there are no physical signs of damage to the cylinder
● check the valve assembly on each cylinder for damage
● inspect the chains or other device used to secure the acetylene and oxygen
cylinders.

Assembly of the gauges, hoses and blow pipe

● Make sure that each regulator is the correct type for the cylinder it is to
be attached to and that the regulator is designed for the pressure of the
cylinder.
● Open the oxygen valve assembly briefly before attaching the oxygen
regulator. This is to eliminate the potential for a dust explosion.
● NEVER open the acetylene control valve to ‘blow-out’ as this could cause a
fire.
● Inspect the regulator and cylinder valve for the presence of any oils or
grease. If present, DO NOT USE.
● Make sure the adjusting screw on the regulator has not been damaged.
● Wipe the connection seats with a clean cloth.
● Connect the gauges to the cylinders. Typically, oxygen hoses are blue and
acetylene hoses are red. Remember that the acetylene hose will have left-
hand threads and the fitting will be a male type, to prevent accidental
switching of the two hoses/gauges. Tighten them with the correct size of
open-ended spanner. Take care not to damage the brass threads and do not
over-tighten or the brass thread could snap.
● Make sure that the flashback arresters and non-return valves are in good
condition and fitted to the gauges.

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