Ever wonder why there have been so many different kettle temperature controls available?
As I was told, many years ago, the first temperature control was by Cleasby Manufacturing in San Francisco. It seems their next door neighbor was I.T.T. General Controls. In a conversation with a salesperson, the subject came up of overheating asphalt. It was suggested to use the thermopilot B61 valve control, normally used on a water heater. This required a pilot flame that “proved” the thermopilot to open and close the main gas valve.
In about 1955, Roofmaster came up with a 12 volt, battery operated control system. This had a solenoid valve that would operate for either liquid or
vapor LP fuel. By being able to work on liquid, it could work in colder temperatures and not freeze the LP tanks. A nice by product was that we used a “starter-generator” on the pump engine, so you didn’t have to hand start the engine on a cold morning.
A third type of control is the Hi-Low control. This uses a temperature sensor that expands with heat and will slowly open and close the gas valve, regulating temperature. A plus of this type of control is that it can be used on any kettle. We currently install them on smaller kettles that are used by shower pan contractors in addition to the
patented Roofmaster cold process material heating WarmMaster.
With fewer and fewer large kettles being sold, we see a lot of the Hi-Low controls being used. The shower pan people usually light their kettle in the street while they are laying up the pan. By the time they are ready to mop, the asphalt is hot, without having to worry about overheating.
As in other industries, there is always a story of evolution that can be told.