sprinklernotes
Inspector’s Test Connection
You asked the following question: Section 16.14.3.4 only mentions remote trip
test connection requirements for double-interlock preaction systems. Does this
mean that non-interlock and single-interlock preaction systems do not require a
remote trip test connection off the remote branch line? If so, why not?
In response to your question(s), we have reviewed NFPA 13, Standard for the
Installation of Sprinkler Systems, 2019 edition.
Our informal interpretation: Remote inspector’s test connections are not
required for non-interlock or single-interlock preaction systems.
Inspector’s test connections are required if the preaction system utilized
supervisory air per section 16.14.3.1, but the location of the inspector’s test
connection is prescribed in section 16.14.3.3:
16.14.3.4 For double interlock preaction systems, the trip test connection or
manifold shall be located on the end of the most distant sprinkler pipe in the
upper story and shall be equipped with an accessible shutoff valve and a plug
not less than 1 in. (25 mm), of which at least one shall be brass.
Currently, only double-interlock are required to be located at the end of the
most hydraulically remote line for trip testing, while non-interlock and
single-interlock preaction systems can be placed anywhere after the alarm
devices. Since a non-interlock preaction system could actuate by the loss of
air through the activation of a single sprinkler, the inspector’s test should
be located off the hydraulically most remote branch line, but it is not
currently required by the standard. AFSA staff intends to submit a public input
for the 2025 edition of NFPA 13 to clarify this section.
