Liquid Level Indicators Should be Standard on all Suppression Systems

By: Scott Nichols of Specialized Fire

I recently posed a question on Linkedin hoping to initiate a conversation regarding the design of Gaseous suppression systems. I would like to see NFPA 2001 amended to make all cylinders sized 125 pounds and up required to have liquid level indicators and low pressure switches. Anyone else care to comment? Too many times companies have bid new installation work and left out critical components which in the end have hampered the effectiveness of the system. Specifically low pressure switches on the cylinders and Liquid Level Indicators for the semi-annual agent check.

The reasoning is as follows, if a cylinder is losing pressure you want to remedy that as soon as possible and not wait for the semi-annual inspection of the cylinder. Loss of pressure and agent can severely impact the performance of the system and releasing any agent into the atmosphere for any reason other than extinguishing, is unacceptable.

Now weighing of the agent is labor intensive, usually requires 2 technicians, and introduces an element of risk to both our customers and the technicians. Bringing a large scale on site, removing cylinder straps, disconnecting piping, moving the cylinder(s) and then placing them back in place, not my idea of a fun afternoon.  Let’s take another scenario, cylinders mounted in the ceiling or on walls, without LLI’s this really presents a challenge and a danger. Having walked into a number of computer rooms where this was the design and talking to the customers their reaction is always the same, “What do mean, weigh the tanks?”

The responses to my question were very supportive, with Shawn Mullen offering to forward the idea to the FSSA technical Committee to pursue. Tim Krulan suggested that I draft the proposal and send it to NFPA 2001 Committee and Ed Armm recommended that self contained HVAC be exempt from shutdown to reap the benefit of mechanical mixing and prevention of the computers overheating.

After all this I think the best approach would be for us as distributors/installers of these systems, is to go to our manufacturers and request that these components are not an option to purchase. The low pressure switch and Liquid Level Indicators are automatically included when you order a cylinder. This makes for a level playing field and good design, your technicians will thank you for it.

If you would like to view a PDF of this article, please click here: Scott Nichols June 2010 Tech Notes


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