On September 28th, 2011 we were asked this question by Chris Redmond, PE at Redmond Engineering & Design in Michigan:
"I have specified and used General Air for years and have recently come up with a dilemma. An AHJ states that the air compressor must meet NFPA 13 requirements (2007 Section 18.104.22.168) that the air supply be available at all times. How have other customers handled this? Do I have to tell the owner to provide a secondary means of power?"
To be clear, NFPA 13 22.214.171.124.1 reads, "The compressed air supply shall be from a source available at all times."
Our Customer Service Manager Ray DeCecco responded:
"The code is stating that you must have an air compressor attached to the system at all times; in other words, you can’t fill a system and then remove the air compressor for use elsewhere. This does not refer to the power source. There are some very rare cases where the AHJ requires a back up power supply but this is his requirement not code. Though we do offer them, a generator or inverter charger is very expensive. If there is a critical dry system application normally a double interlock pre-action system will be specified."
As you already know, code interpretation varies from place to place and person to person. Always work closely with your local code enforcement officials to insure that your system and it's components are compliant. That being said we are very glad that Chris contacted us regarding this issue. We are always happy to put our years of experience to work for our customers, furthermore we will also talk to AHJ's and other code officials to explain our position on your behalf.
If you have a question about how a part of code regarding air compressors for dry pipe systems is typically interpreted please contact us be calling 800-345-8204, via email or by leaving a comment below.