Electrical Isolation of Structures

excavation and backfilling. There shall be a minimum of 2 continuity bonds

between each structure and other than welded or threaded joints.

Electrical continuity shall be tested across joints with other than welded

or threaded joints and across metallic portions of sewage lift stations and

water booster stations.

2.4.19.1

Resistance Bonds

Resistance bonds shall be adjusted for minimum interference while achieving

the criteria of protection. Alternate methods may be used when approved.

2.4.19.2

Stray Current Measurements

Stray current measurements shall be performed as indicated. Alternate

methods may be used when approved. The stray current test report shall

indicate location of test, type of pipes tested, method of testing, [_____].

2.4.20

Electrical Isolation of Structures

Isolating fittings, including isolating flanges and couplings, shall be

installed above ground or in a concrete hand hole. As a minimum, isolating

flanges or unions shall be provided at the following locations:

a.

Connection of new piping to existing pipes.

b.

Pressure piping under floor slab to a building.

Additionally, isolation shall be provided between new pipe lines and

foreign pipes that cross the new lines within 3 m 10 feet.

2.5

MAGNESIUM ANODES

Weights and dimensions of magnesium anodes shall be approximately as

follows:

TYPICAL MAGNESIUM ANODE SIZES

(Cross sections may be round, square, or D shaped)

NOMINAL GROSS

NOMINAL

APPROX.

WT kg PACKAGED

NOMINAL PACKAGE

WT. kg.

SIZE (mm)

IN BACKFILL

DIMENSIONS (mm)

1.4

76

X

76

X

127

3.6

133

X

133 X 203

2.3

76

X

76

X

203

5.9

133

X

133 X 286

4.1

76

X

76

X

356

12.3

133

X

508

5.5

102

X

102

X

305

14.5

191

X

457

7.7

102

X

102

X

432

20.5

191

X

610

14.5

127

X

127

X

521

30.9

216

X

711

22.7

178

X

178

X

406

45.5

254

X

610

TYPICAL MAGNESIUM ANODE SIZES

(Cross sections may be round, square, or D shaped)

NOMINAL GROSS

NOMINAL

APPROX.

WT LBS PACKAGED

NOMINAL PACKAGE

WT. LBS.

SIZE (IN)

IN BACKFILL

DIMENSIONS (IN)

3

3X3X

5

8

5 1/4 X 5 1/4 X 8

5

3X3X

8

13

5 1/4 X 5 1/4 X 11 1/4

SECTION 13112A

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