No alteration that might invalidate the certificate or other documents relating to the safety of the apparatus should be made to any apparatus without appropriate approval.

If replacement components such as cable glands, conduit or conduit accessories, are available only with thread forms which differ from those provided on the apparatus suitable adapters having component approval should be employed.

Checks should be made for obstruction around flanges of the equipment. The dimensions of the gaps at flameproof joints should be checked periodically during maintenance to see that they do not exceed the maximum figure specified in IS-2148. At such intervals as experience may prove desirable, the flanged joints should be separated and the faces examined for possible defects resulting from corrosion, erosion or other causes. If flanges are to be sealed, then new nonsetting grease or tape should be used on reassemble.

Equipment enclosures and fitting should be examined to see that all stopping plugs and bolts are in position and tight. Locking and sealing devices should be checked to confirm that they are secured in the prescribed manner.
Replacement cover securing fasteners, nuts, studs and bolts should be types specified by the manufacturer for the particular apparatus.

No attempt should be made to replace or repair a glass in a flameproof enclosure, e.g. in a luminaire or other enclosures, except by the complete assembly or part obtainable from the manufacturer, or complying with the flameproof certificate.

Repairs and refurbishing of apparatus with type of protection 'd' should be performed only by the original manufacturer, his authorised agents or a repairer who is conversant with the construction standards for flameproof equipment and demonstrates the ability to understand certification restraints.