For decades, foam chambers have been the fire fighting fixed system of preference in protecting large diameter storage tanks. Williams Fire & Hazard Control is proposing a simpler, more cost effective alternative – foam wands.
On Dec. 14, Williams F&HC conducted a test of their latest wand, a stainless steel, maintenance free applicator that delivered foam over a distance three times as great as a standard foam chamber in the same or less time.
"We’re once again thinking outside the box," Williams F&HC founder Dwight Williams said.
Foam wands have been a standard tool in the industrial firefighter’s bag for many years. The configuration makes it easy to slip into position over the rim of a storage tank. Once the firefighter retreats to a safe distance, the wand delivers foam at a 4:1 expansion rate to put out the fire in a specific area.
With management increasingly focused on containing costs while reducing risks, using portable systems such as wands as a replacement for permanent foam chambers is becoming more widely accepted.
To protect a 300 foot diameter tank, 12 foam chambers placed around the rim is necessary. The same sized tank can be adequately protected in only two minutes with four of the new Williams F&HC foam wands hung from the tank shell.
Foam wands are not the only Williams F&HC fire fighting tool designed to fasten to a tank shell. The Daspit Tool, 500-to-2,000 gpm automatic nozzle, has proven to be extremely effective against seal fires, the fires that spread around the rubber seal between a floating roof and the tank shell.
However, employing the Daspit Tool can be time consuming, involving the difficult work of laying the hose line up the tank ladder. This can allow the fire to spread as equipment is put into place.
Further tests using foam wands on storage tank seals to develop installation and operation recommendations are planned for the future.
A fire chief on hand for the demonstration said he wanted to see the potential for using the tool on new tanks being built.
"As I watched the test, I noted that the foam from the foam chamber traveled the NFPA 11 required 40 feet in one minute and 41 seconds to extinguish the test fire in a pan," the chief said. "Foam from the Williams Fire and Hazard Control wand traveled 120 feet to roll over and extinguish the fire in 1 minute and 14 seconds."
"It far exceeded my expectations," the chief said. "It will be able to exceed the standards while having less of a maintenance challenge for the facility."
The wand and supply line appear to be a simple system to install and maintain, he said.
"Its effectiveness is its directed flow of foam in small bubbles from the wand in opposite directions," the chief said. "It yields minimum waste even when facing wind. It flows down its targeted course quickly while also flowing through weep holes present for water run off to prevent sinking the tank’s floating roof. It’s very effective while simple and safe to operate."
The remote foam drafting and proportioning system used allowed operators to be a safe distance from the hazards of the fire. The primary challenge will be connecting the supply hose if supply lines stop at the tank, said David White with Fire & Safety Specialists, present with other third party observers invited to evaluate the system.