Someone once said that "All instructors are created equal, some just have better slides and training props." Do you have a special training prop or an idea for getting the point across? Send us a brief write-up in 500 words or less using the format below and we will post it as an Instructor's Tip. Please include your name, company/fire department affiliation, address, and telephone number. You can e-mail your ideas and photos to us at
webmaster@propanesafety.com

Instructor's Tip No.1

FLAME IMPINGEMENT / CONTAINER COOLING DEMONSTRATION
submitted by :
Al Stillwaggon, H.R. Weaver and Company, Inc., Newburgh, New York

Cooling an exposed propane container and maintaining a wet surface area on the outside of the exposed tank is critical during firefighting operations. Cylinders and tanks can fail early in the fire if the container is not adequately cooled.
A simple training prop can be made for classroom demonstration to show how containers fail when exposed to fire and how failure may be prevented by application of cooling water.

EQUIPMENT NEEDED
Three soda cans, a simple rack to hang the cans on, a hand held propane torch, a safety striker to light the torch, and a water spray bottle, and a hand-held fire extinguisher (you can never be too safe!)

PROCEDURE
The first can should be empty, the second can should be filled 50% with water, and the third can 75% with water.

The torch is placed on the first (empty) can and the aluminium fails almost immediately. The instructor should use this opportunity to discuss the principle of heat transfer by conduction.

The torch is then passed to the second can and the flame is applied to the lower half of the can below the liquid level. The can does not melt through as long as the flame remains in contact with the can below the liquid level. The water in the can will come to a full boil and pass steam out through the top of the can. The instructor should use this opportunity to discuss how heat is being conducted through the can to the liquid inside and raising the interior temperature of the liquid to its boiling point. Once this point is made, the torch should be raised above the liquid level into the vapor space so students can see that the can burns through very quickly.

Using a water spray bottle, the instructor should apply water to the outside of the can and maintain the outside wetted surface as the torch passes from the liquid filled area of the can to the area above the liquid level. The torch should be held in one area of the can as the water is continuously sprayed onto the can at the point of impingement. Use this opportunity to discuss the importance of maintaining cooling water at the point of impingement as well as on the entire exposed surface of the tank. If the water spray stops, the can will burn through in a short period of time.
RELATING THE DEMONSTRATION TO THE TEXT
The instructor can use this demonstration in delivering material in Section 3 "Physical Properties and Characteristics of Propane" or in Section 8 Scenario #6 "BBQ Grill Fire Next to a Home" or in Scenario #7 "Fire Involving a Stationary Tank on a Farm."
The instructor can also tie this demonstration into Scan Sheet C "Boiling Liquid Vapor Explosion" (pp 134 to 137) and Figure 8-3 "Cooling Water Must Be Applied at the Point of Impingement and On the Entire Upper Half of the Tank Shell" (p-139.)

Instructor's Tip No.2

USING CUTAWAY CONTAINERS
submitted by :
Joe Jesso and Henry McDermott, Eastern Propane Gas, Inc. Rochester, New Hampshire.

EQUIPMENT NEEDED:
One used 20 pound propane cylinder with standard service valve and overfilling prevention device.

PROCEDURE:
Obtain a used 20 pound cylinder and valves from your local propane dealer. Make sure that the tank has been rendered safe and properly purged. Cutaway the outside section of the tank so that students can see the interior. Clean and paint the prop. Standard valves and fittings used locally can be installed and demonstrated in the classroom. Other types of tanks can be used in the same way.

MOBIL TRAINING UNITS
Submitted by:
Dale Mashuga, Customized Training program Director, Anoka-Hennepin Technical College, Anoka, MN Contact: dmashuga@ank.tec.mn.us