Hydrostatic Leak Testing?
Hydrostatic Leak Testing is used to test components for
leaks by pressurizing them inside with a liquid. This testing method
can be used on piping, tanks, valves and containers with welded or
fitted sections. Leaks can be found up to about
1x10-4 std cc/sec . NOTE: Hydrostatic Testing can be
nondestructive test as well as used as a
Hydrostatic Leak Testing requires that a component be completely
filled with a liquid such as water. Pressure is slowly applied to
the liquid until the required pressure is reached. this pressure is
held for the required time at which point the component is inspected
visually to locate leaks.
color developer for water can be sprayed on seams and welds for
immediate color change and location of leak. Even if leak happened
overnight and has since dried, the color change remains visible.
PinPOINT color developer can be used the same way if the container
Tracer dyes can be
introduced to containers filled with oil or water, for clear visual
Fluorescent tracer dye
can be added to the fluid in containers and leakage can be found
easily with black lights.
Hydrostatic Testing - Questions & Answers
this test is a leak detection method, a burst test or
Organizations such as A.S.M.E. and the Coast Guard often
specify it without being clear.
Should a leak test be done before or after the
a more sensitive leak test is to also be conducted it
should be done before, not after.
What about painting and insulation before the test?
ASTM standard permits, but recommends against, a test
after painting and increases the normal test time of 6
minutes per centimeter of wall thickness by a factor of
10 if parts of the test object are covered by
What effect does increasing the pressure have?
hydrostatic test fluid will tend to clog small leaks and
vacuum drying or heating may have difficulty in removing
water vapor from leaks lxI0-6 std cm3/sec