Pipeline construction word for the hot coal tar or asphalt enamel poured over pipe and wrapped with felt or glass mat. Crews talk of doping the pipe, the dope crew and the dope kettle, and plenty of big-inch lines in service carry dope. Aged dope gets brittle, can disbond and shield CP current, so digs on these lines often find corrosion hiding under the coating.
This old line has dope on it, brittle as glass, go easy with the excavator or it'll shatter.
Also heard as
- coal tar enamel
- hot dope
- enamel
Related terms
Field joint coating
Coating applied on site over the bare girth weld zone left between factory-coated pipe joints.
Cathodic disbondment
Loss of coating adhesion around a holiday caused by the alkali and hydrogen that cathodic protection generates.
Bell hole
Excavation dug around a short section of buried pipe so crews can inspect, repair or connect to it.