Inspector's Test Remote or at Sprinkler Riser?

6/30/2025

Is there a specific code that requires an inspector's test on a fire sprinkler system to be at the most-remote part of the system, or is it only required at the riser near the main drain?

Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

6 Comments

Pete H

6/30/2025 06:30:35 am

From NFPA 13 (2016):

8.17.4 System Components
8.17.4.1 Wet Pipe Systems
-
8.17.4.1.4 The alarm test connection shall be permitted to be installed in any location on the fire sprinkler system downstream of the waterflow alarm.

-
A.8.17.4.1 The purpose of this alarm test connection is to make sure the alarm device is sensitive enough to determine the fire flow from a singe sprinkler and sound in alarm. The purpose of this test connection is not to ensure that water will flow through the entire system.

When this test connection is installed on the upper story, and at the end of the remote branch line, the user is able to tell that there is water flowing in one path through the system, but there is no assurance that water will flow to other branch lines. Putting the test at the most remote portion of the system causes the introduction of fresh oxygen into a large part of the system each time the alarm is tested and increases the corrosion that will occur in the piping.
The discharge should be at a point where it can be readily observed. In locations where it is not practical to terminate the test connection outside the building, the test connection is permitted to terminate into a drain capable of accepting full flow under system pressure. In this event, the test connection should be made using an approved sight test connection containing a smooth bore corrosion-resistant orifice giving a flow equivalent to one sprinkler simulating the least flow from an individual sprinkler in the system (see associated figures). The test valve should be located at an accessible point and preferably not over 7 ft above the floor. The control valve on the test connection should be located at a point not exposed to freezing.

Todd E Wyatt

6/30/2025 08:33:44 am

Per NFPA 13-2023 edition ...

Chapter 16 Installation of Piping, Valves, and Appurtenances
16.14 System Connections.
16.14.1.1
An alarm test connection not less than 1 in. (25 mm) in diameter, terminating in a smooth bore corrosion-resistant orifice, giving a flow equal to or less than one sprinkler of a type having the smallest K-factor installed on the particular system, shall be provided to test each waterflow alarm device for each system.

16.14.1.2
The test connection valve shall be accessible.

16.14.1.3
The discharge shall be to the outside, to a drain connection capable of accepting full flow under system pressure, or to another location where water damage will not result.

16.14.1.4
The alarm test connection shall be permitted to be installed in any location on the fire sprinkler system downstream of the waterflow alarm.

A.16.14.1
The purpose of this alarm test connection is to make sure the alarm device is sensitive enough to determine the flow from a single sprinkler and sound an alarm. The purpose of this test connection is not to ensure that water will flow through the entire system. When this test connection is installed on the upper story, and at the end of the most remote branch line, the user is able to tell that there is water flowing in one path through the system, but there is no assurance that water will flow to other branch lines. Putting the test connection at the most remote portion of the system causes the introduction of fresh oxygen into a large part of the system each time the alarm is tested and increases the corrosion that will occur in the piping. The discharge should be at a point where it can be readily observed. In locations where it is not practical to terminate the test connection outside the building, the test connection is permitted to terminate into a drain capable of accepting full flow under system pressure. In this event, the test connection should be made using an approved sight test connection containing a smooth bore corrosion-resistant orifice giving a flow equivalent to one sprinkler simulating the least flow from an individual sprinkler in the system. [See Figure A.‍16.14.1(a) and Figure A.‍16.14.1(b).] The test valve should be located at an accessible point and preferably not over 7 ft (2.1 m) above the floor. The control valve on the test connection should be located at a point not exposed to freezing.

Glenn Berger

6/30/2025 08:08:43 am

Pete H. is correct for a wet-pipe sprinkler system.

For a dry-pipe sprinkler system, the inspector's test station is located at (close to) the most remote sprinkler. You are also measuring the time for the water to reach the end of the system.

I currently cannot access NFPA 13 to provide a specific reference.

Anthony

6/30/2025 08:10:45 am

for wet systems:

My understanding is that this used to be best practice prior to corrosion mitigation concerns. Its also a requirement for dry system trip times so the two ideas merged into a test connection at the end of the system.

Modern wet systems only require testing to ensure the alarm (flow switch or gong) is functional.

For dry systems:

8.17.4.2.2 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 shut off valve and a plug not less than 1 in. (25 mm), of which at least one shall be brass. (13-16)

Jesse

6/30/2025 08:40:17 am

For wet-systems, certainly. Basically we're just wanting to ensure that the flow device activates.

For dry systems, the inspector's test should as close as possible to the most remote sprinklers.

Jack G

6/30/2025 08:43:36 am

All are correct .
One reason i dont like the wet inspectors test to be remite is for the induction of air into the system.
When cool water ( new flow ) is introduced with the air, it gradually increases in temperature ( say 60 to 70 degrees f) 3% of air in the system and a 10 degree rise-- boyles law-- will double the pressure in the system ( grids are famous for this ) so it is also important to have a relief valve or air releases at various points.
Dry system trip times are measured at the remote points fir this " direct run " of system water.
As an apprentice I once left a drop out of a small office in a closet next to the riser.
We trip tested the system, got water at the end, but we heard this sound of air whistling by the riser room. Fitter yelled ( open outlet ) i quickly grabbed a drop and followed my ears. We figured it took about 3 minutes for the drop nearest the riser to get water . When central came out with tgeir trip test program, thats something i check ( lol) all the time.

Inspector's Test Remote or at Sprinkler Riser?

Leave a Reply.

ALL-ACCESS

SUBSCRIBE

COMMUNITY

YOUR POST

PE EXAM

FILTERS

ARCHIVES

PE PREP SERIES