3.1.4.1
Permanent Reference Electrode Calibration and Installation
Provide [prepackaged] [copper copper-sulfate] [silver-silver chloride]
[zinc] reference electrode(s) as indicated in the drawings. Prior to
installation, soak the [prepackaged] reference electrode in a container of
potable water for 30 minutes. Do not use seawater [except for
silver-silver chloride electrodes intended for use in seawater]. Calibrate
the permanent reference electrode in the presence of the contracting
officer or his approved representative by measuring the potential
difference between the permanent reference electrode and an independent
(portable) calibrated reference electrode placed in the water adjacent to
the permanent reference electrode. [Potential differences between the two
electrodes of the same generic type should not exceed [10] [15] millivolts
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.
3.1.5
Bonding Boxes
Provide structure bonding boxes in locations [as indicated] [where the
protected structure crosses or comes into close proximity to other metal
structures that are unprotected or protected by its own electrically
isolated cathodic protection system(s)].
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
Provide insulating unions aboveground or within manholes as indicated.
[Cut pipe ends square, remove fins and burrs, cut taper pipe threads in
accordance with ASME B1.20.1.] 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.
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 at joints not welded or threaded to
SECTION 13111N
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