UFC 3-240-13FN
25 May 2005
APPENDIX D
CORROSION TESTING WITH TEST NIPPLE ASSEMBLY
D-1
PURPOSE. Corrosion tests with metal test specimens are used to
determine how corrosive water is toward a specific metal. Although test nipple
assemblies (referred to as "tester") can be used in many applications, they are used on
military installations to evaluate corrosion problems in steam condensate return
systems. See ASTM Standard Test Method: Corrosivity of Water in the Absence of Heat
Transfer, D2688-94(1999)e1.
D-2
APPLICATION
D-2.1
Tester Specifications. The tester consists of three 76-millimeter by 19-
millimeter (3-inch by 0.75-inch) National Pipe Thread (NPT) nipples, connected by two
couplings (see Figure D-1). The center nipple contains short inserts machined from
steel tubing similar to the steel pipe in the condensate system. The outside diameter of
the inserts is approximately the same as the inside diameter of the center 19-millimeter
machined coupling. The two end nipples of the tester are installed between two unions
in such a manner that condensate will constantly flow through the tester. See paragraph
D-3 for detailed installation instructions.
D-2.2
Likelihood of Corrosion. Serious corrosion is more likely in large-area
heating systems that have long return lines. More concentrated systems, such as
laundries and low-pressure closed systems in which there is very little feedwater
makeup, generally experience much less condensate return line corrosion.
D-2.3
Scale of Testing. If the test points are well chosen, information obtained
from one or two condensate return systems on an installation or base is generally
sufficient to serve as a survey of the entire facility. One or more testers would be
installed in the largest area heating system and another in a smaller system. The testers
should be installed at points where maintenance work has been required due to
corrosion.
D-2.4
Receipt of Tester. The supplier provides the tester complete and ready
for installation. An appropriate data form is also provided with the tester. This form must
be completed by the user for correct interpretation of corrosion that may occur on the
tester inserts. The user is required to draw a picture to show how and where the tester
was installed.
D-2.5
Removal of Tester. At the end of the test period, the tester is removed.
The tester is rinsed internally for several seconds with very hot water, drained, and
immediately capped on both ends with the plastic caps that had been supplied with the
tester.
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