PIPING SYSTEM DESIGN
Christopher G. Ziu, P.E., C.I.P.E.
Handbook of Double Containment Piping Systems
McGraw-Hill, Inc., Publishers
New York, New York
878 Pages, Copyright 1995
Manager Piping Products
Orion Fittings, Inc.
Kansas City, KS
History of Double Containment Piping
Up until the 1970s, dual arrangements of piping systems utilizing a carrier pipe
with a secondary piping providing containment for purposes of environmental
protection or safety were limited to highly specialized applications. These involved
rare applications in the nuclear, gas, or chemical processing industry, where highly
toxic or lethal chemicals or fluids were transported. The use of an outer jacket to
maintain a positive seal around a primary carrier piping system and protect the
primary piping was rarely encountered.
In the 1970s, several large U.S. electronics manufacturers began placing their
underground, and in some cases aboveground, hazardous chemical piping systems
piping within an outer jacket for the sole purpose of preventing leakages from
getting into the ground water supply. Part of the reason for doing so was due to
inadequate performance on the part of ordinary single-walled piping components
intended to handle these chemicals. Leakages from joints, failures of piping materials
due to poor manufacture or installation practices, inappropriate material selection,
and soil corrosion were some of the contributing factors. Thus began the modern
day practice of placing underground piping systems within a secondary containment
piping system for the sole purpose of protecting the local environment.
GENERIC DESIGN CONSIDERATIONS
Unfortunately, many of these early systems met with complications that resulted
in less-than-successful performance. The first attempts at dual arrangements met
with frequent failure. This was primarily due to systems being designed with combi-
nations of piping components whose geometries were not readily compatible. Also,