APPENDIX E (continued)
(c) Except for unprotected copper inserted in ferrous pipe, each
pipeline must be electrically isolated from metallic casings that are a part
of the underground system. However, if isolation is not achieved because it
is impractical, other measures must be taken to minimize corrosion of the
pipeline inside the casing.
(d) Inspection and electrical tests must be made to assure that
electrical isolation is adequate.
(e) An insulating device may not be installed in an area where a
combustible atmosphere is anticipated unless precaution are taken to prevent
(f) Where a pipeline is located in close proximity to electrical
transmission tower footings, ground cables or counterpoise, or in other areas
and protective measures must also be taken at insulating devices.
[Amdt. 192-4, 36 FR 12302, June 30, 1971, as amended by Amdt. 192-33, 43 FR
39390, Sept. 5, 1978]
Each pipeline under cathodic protection required by this subpart
must have sufficient test stations or other contact points for electrical
measurement to determine the adequacy of cathodic protection.
[Amdt. 192-27, 41 FR 34606, Aug. 16, 1976]
(a) Each test lead wire must be connected to the pipeline so as to
remain mechanically secure and electrically conductive.
(b) Each test lead wire must be attached to the pipeline so as to
minimize stress concentration on the pipe.
(c) Each bared test lead wire and bared metallic area at point of
connection to the pipeline must be coated with an electrical insulating
material compatible with the pipe coating and the insulation on the wire.