when the [sensing windows of the] two electrodes being compared are not
more than 2 mm 1/6 inch apart but not touching.] [Zinc permanent reference
electrodes should be within the range of -1000 to -1150 millivolts when
calibrated with an independent (portable) calibrated copper-copper sulfate
reference electrode with the two electrodes being not more than 2 mm 1/6
inch apart but not touching.] Permanent reference electrodes not within
these potential differences shall be removed from the construction site by
the end of the day and replaced at the contractor's expense. [Prior to
completely backfilling over reference electrodes, again verify the accuracy
of the reference electrode.] The testing provision shall also apply to
replacement reference electrodes as well.
3.1.6
Insulating Flange Sets
[Provide insulating flange sets aboveground or within manholes as
indicated]. [Locate insulating flanges on lines entering buildings at least
305 mm 12 inches above grade or floor level.] [Cut piping and provide
flanges into place. Carefully align flange bolt holes and weld flange to
pipe in accordance with ASME B16.25.] [Electrically isolate pipelines
entering buildings from the structure wall either below or above ground
with an electrically isolating wall sleeve.] Provide insulating flange
sets into place without springing or forcing. Carefully install flange
bolt sleeves to avoid damage to the sleeves. [Cover insulating flanges with
an electrically insulating coating.]
3.1.7
Dielectric Unions
[Cut pipe ends square, remove fins and burrs, cut taper pipe threads in
accordance with ASME B1.20.1.] Provide insulating unions as indicated.
Work piping into place without springing or forcing. Apply joint compound
or thread tape to male threads only. Backing off to permit alignment of
threaded joints shall not be permitted. Engage threads so that not more
than three threads remain exposed. [Cover unions with an electrically
insulating coating.]
3.1.8
Joint Bonds
Provide joint bonds on metallic pipe to and across buried flexible
couplings, mechanical joints, flanged joints [except at places where
insulating joints are specified] and joints not welded or threaded to
provide electrical continuity. Connect bond wire(s) to the structure(s) by
use of exothermic weld kit(s). Clean the structure surface by scraping,
filing or wire brushing to produce a clean, bright surface. [Weld
connections using exothermic kits in accordance with the kit manufacturer's
instructions.] Check and verify adherence of the bond to the substrate for
mechanical integrity by striking the weld with a 908 gram 2 pound hammer.
Cover connections with an electrically insulating coating [which is
compatible with the existing coating on the structure].
3.1.9
Casings, Insulation, and Seals
Where the pipeline is installed in a casing under a roadway or railway,
insulate the pipeline from the casing, and seal the annular space against
intrusion of water.
3.1.10
Concrete
Concrete shall be 20 Mpa 3000 psi minimum ultimate 28-day compressive
strength with 25 mm one inch minimum aggregate conforming to [ASTM C 94]
SECTION 13110N
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