to permit tape coating shall be primed and wrapped with an
underground type pipe tape system or two-part epoxy system.
b.
Couplings and fittings that cannot be properly taped shall be
enclosed in a [spaced mold manufactured for the purpose] [shroud
of reinforced kraft paper] and filled with [cold applied
dielectric compound] [hot applied bituminous compound not
exceeding 135 degrees C 275 degrees F in application temperature].
3.4.3.3
Electrical Isolation of Structures
Electrical isolation of structures shall be as follows:
a.
Isolating Fittings: Isolating flanges and couplings shall be
installed aboveground, or within manholes, wherever possible, but
an isolating device that electrically separates a pipeline shall
not be installed in a confined area where a combustible atmosphere
may collect unless precautions are taken to prevent arcing such as
by means of externally located surge arresters, grounding cells,
or other means. Isolating flanges and couplings in lines entering
buildings shall be located at least 300 mm 12 inches above grade
or floor level. Pipelines entering buildings either below or
above ground shall be electrically isolated from the structure
wall with an electrically isolating [gas tight wall sleeve.] [wall
sleeve.]
b.
Gas Distribution Piping: Electrical isolation shall be provided
at each building riser pipe to the pressure regulator, at all
points where a short circuit to another structure or to a foreign
structure may occur, and at other locations as indicated.
c.
[Steam] [High Temperature] [Chilled] [Water] [Line Supply and
Return Piping] [Line Conduit]: Electrical isolation shall be
provided at each building entrance, and at other locations as
indicated.
d.
[Fuel] [Gasoline] [Storage Tanks] [Fire Suppression] [_____]:
Electrical isolation shall be provided in each pipe [at the
building] [at the tank] as shown.
e.
Copper Piping: Copper piping shall be [electrically isolated at
both ends of the pipe run] [wrapped with pipeline tape and
electrically isolated at both ends].
f.
Underground Storage Tanks (UST): Tanks shall be electrically
isolated from other metallic structures. Components protected
with the tank such as pipes, vents, anchors, and fill pipes shall
be bonded to the tank.
3.4.4
Dissimilar Metals
**************************************************************************
NOTE: This paragraph will be coordinated with and
referenced in mechanical and electrical
specifications.
**************************************************************************
Buried piping of dissimilar metals including new and old steel piping,
excepting valves, shall be electrically separated by means of electrically
SECTION 13112A
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