Double Walled Piping Systems DOUBLE WALLED PIPING SYSTEMS The design and construction of a double wall pipe is more complex than a single wall

When evaluating single walled pipe vs. double walled pipe systems, one must consider two important types of failures: 'functional failure' and 'containment failure'. A functional failure is defined as pipeline system damage without loss of product containment integrity to the environment. A containment failure is defined as pipeline system damage with loss of product containment integrity, that is product loss to the external environment. Hence a breach of either the inner or outer wall of a double wall pipe is considered as a functional failure, provided the other pipe retains its integrity or containment. Loss of containment through only one of the two pipes comprising the double wall system is not considered to be a containment failure of the system. Any failure to a single walled pipe system would constitute a containment failure.