Inspect and Replacing Zinc Plugs

RG9835-UN-05JAN99

Inspect Zinc Plugs

A - Zinc Plugs

B - End Cap

Two zinc plugs (A) are installed in the sea water cooling system to help reduce the corrosive action of salt in the sea water. The reaction of the zinc to sea water causes the plugs to deteriorate, instead of the more critical cooling system parts. Therefore, the zinc plugs MUST BE inspected every 250 Hours.

NOTE: Zinc plugs are located in each heat exchanger end cap and are mounted on hex-head pipe plug.

1. Remove zinc rod from each end cap (B) and observe condition of each.

2. Tap the zinc rods lightly with a hammer. If rod flakes apart when tapped, install a new zinc plug.

3.

RG6007-UN-27JAN92

Zinc Plug Erosion

A - Measure Zinc Plugs

B - Measure Length

C - Measure Diameter

If length is less than 15.9 mm (0.63 in.) or outer diameter is less than 4.8 mm (0.19 in.) on either plug, replace all zinc plugs.

NOTE: Zinc plug new part dimensions are 31.8 mm (1.25 in.) long and 9.5 mm (0.38 in.) outer diameter.