The coating system consists of applying a coat of coal-tar enamel having a minimum thickness of 24 micron/2.4mm over the primed pipe and one wrap of glass-fiber mat.

A second coat of coal-tar enamel having a minimum thickness of 2400 micron/2.4mm follows this and wrap of glass-fiber mat followed immediately by an outer-wrap of coal-tar impregnated glass fiber felt.

The minimum thickness of coating (without the outer-wrap) is 4800 micron/4.8mm +/- 1.0/0.0mm. When the protrusion of weld seam interferes with this thickness, the thickness of the coating above the weld seam should meet the specified thickness.