Firefighters demonstrate how they push back flames in order to reach the shutoff valve on a burning bobtail.

Flames shot 40 feet across the gravel lot to the edge of a singed tree line, hissing angrily and dancing in an ever-changing afternoon breeze.

Propane marketers are taught the A-B-Cs of using different kinds of portable fire extinguishers to battle propane fires.

"You don't know how hot that flame is until the gas stream is three feet away," testified Dave Alcorn, a bobtail driver for Southern Propane in Jacksonville, Fla., after his turn dousing the blaze. "You read about it in all the safety manuals, but it's not nearly the same as experiencing it."

After burning off product to relieve tank pressure, firefighters show how to change out a faulty valve.

Alcorn was one of 39 employees from 16 area propane companies who got both classroom and real-life experience April 25 at a daylong fire school arranged by the Propane Gas Association of Northeast Florida. They were joined by 15 firefighters from six area departments for instruction on different types of extinguishers, approach and hose techniques, propane properties, codes and firefighting procedures.

Area propane marketers learn firsthand how to douse a raging gas fire by finding the "sweet spot" that the chemical agent can extinguish.

Each marketer took a turn blasting a live propane fire with dry chemical extinguishers, all the while getting schooled about the fire's "sweet spot" and how the chemical agent gets sucked into the fire's vortex before it expands, burns and eventually smothers the flames.

Propane vapor escapes from a vessel after removal of a valve.

"I think anyone who is in this business needs to do this," Tom Mulligan of Mulligan Propane in Palatka, Fla., said afterward. "I got a lot more out of this than I thought I would. It was like someone hit a switch and you suddenly understand all the safety lessons that you have learned."

Jacksonville area propane marketers learn the concerns and strategies of hazmat unit firefighters who respond to propane incidents.

Propane Gas Association of Northeast Florida officers President Scott Manley, Vice President Charlie Brown, Treasurer David Fish and Secretary Patti Mulligan.

About 40 employees from 16 propane companies participated in the fire school.