MAINTENANCE & REPAIR
BY ARIE BREGMAN
Don’t Put Up with Water Hammer!
Did you ever shut off your kitchen faucet quickly at home and hear the
piping rattle in the basement? What
you’re hearing is the common phenomenon of water hammer.
While that sound may be a minor
annoyance in a home situation, expand
the size of the pipes and the pressure
they contain to an industrial level, and
such a noise would mean a major problem on your hands. Water hammer has
been known to break flanged connections and to burst pipes.
Water hammer is the result of pressure spikes generated within liquid piping systems. (Water hammer occurs not
just in water, but in all liquids; however,
not in gas or air flue streams.) For anyone dealing with water hammer, vital
information is what factors are influencing the severity of the pressure spike
or pressure transients (Figure 1). For
more than 100 years, researchers have
struggled to understand and define the
parameters of that pressure and to
develop equations that can predict
water hammer pressure transients.
Much of this research has been done at
the Delft Hydraulics Laboratory in the
Netherlands, The City University of
London, and Utah State University to
name a few.
In this article, I will highlight key factors that have been discovered as well as
possible solutions for problems that
result from water hammer. (A similar
phenomenon often termed water hammer is “steam hammer.” This is a different issue altogether, which is caused by
steam condensing to a liquid. This article
does not address “steam hammer.”)
Figure 1. Graphical representation of the pressure transients over time
FUNDAMENTALS OF WATER