Lined Pipe

DOE-HDBK-1132-99

In steam, air, and gas systems, the blowdown connections at all low

points may serve as drains and the branch connections off the top of

piping headers may serve as vents.

Vent and drain connections are not required when their function is filled

by system branch connections, equipment vents, and drains or instrument

connections.

Lined Pipe. Special considerations should be given to the design of piping

1.3.4

systems lined with materials such as rubber, cement, glass, or epoxy. The

following guidelines should be considered in the fabrication and erection of such

piping systems:

Maximum spool lengths of lined pipe vary among suppliers.

The method of joining may be flanged, mechanical joint, screwed, or

welded prior to lining. Welding after the lining is installed is generally not

permitted.

When using butterfly valves, consider a potential interference between

the valve disk and lining material, which decreases the inside diameter of

the pipe.

1.3.5

Freeze Protection . In cold climates external piping should be provided with

freeze protection. Preventing piping systems from freezing can eliminate costly

repairs and system outages. Freeze protection typically consists of either steam

or electric heat tracing. Economic considerations dictate which method is

selected.

Avoid routing piping along the inside of exterior building walls or un-

insulated siding in cold climates. Where possible, route piping near

radiant heat sources to prevent freezing.

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