Let’s face it, you don’t buy a heat treating furnace every day. Purchasing a heat treating furnace can be a large undertaking with several variables and costs to consider. We’ve taken our 35 years of experience building heat treat furnaces and compiled the top 6 questions that you need to ask to ensure you are purchasing the best quality furnace for the best value.
We hope this information will empower you to make a sound decision.
- What temperatures can I achieve inside the Furnace? Generally, a Heat Treat Furnace operates from 800 degrees F up to 2200 degrees F. High quality manufacturers should insulate the furnace with a combination of Ceramic Fiber and, Castable Refractory and Heavy Duty Refractory brick. Linings as thick as 12” thick are used on 2200 degree F unit.
- What is a typical Temperature Uniformity Specification for a Direct Fired Heat Treat Furnace? A Heat Treat Furnace typically operates at plus or minus 25 degrees F uniformity inside the furnace’s “working space”. Tighter uniformity (plus or minus 10 degrees F) has been achieved on some direct-fired units. You should also ask about proprietary designs from the manufacturer to ensure optimal uniformity and efficiency.
- How can I be assured air won’t leak and the doors will seal properly over time?
Typically, oven doors will sag over time if not engineered properly. It is essential you ask the manufacturer if they have a proprietary door design that has been tested and proven. Better yet, find a manufacturer that will guarantee their doors for the life of the oven. If they won’t guarantee the doors, you should be skeptical.
- Is the Control Panel approved by an accredited Agency? Any good manufacturer will be accredited by the U.L. The U.L. is an independent, global accredited safety science company aimed at maintaining s high standard of safety in the workplace and quality of the product being manufactured. Control Panels have a U.L. Classified Sticker affixed inside. All components in the U.L. Classified Control Panel are U.L. listed or recognized.
- Is the Combustion System rated to meet Safety Standards: Factory Mutual, IRI and NFPA 86? A Heat Treat Furnace should include numerous safety components including redundant Gas safety shut off valves, Isolation gas cocks, High/Low Gas Pressure Switches, Air Proving switches and flame supervision with Ultra Violet (U.V.) Scanners. Burners should not light until a purge air cycle has been completed at start up. The burners light on low fire and modulate safely to high fire via linkage and drive component.
- Will I receive Installation/Start up/Training assistance? A standard Heat Treating Furnace should be supplied with detailed general arrangement drawings as well as installation drawings. Make sure the manufacturer has engineers on staff that will assist on site with the installation, training and start up of your furnace.
Depending on your requirements, there are several other questions that may come up, but we hope this helps you in your initial stages. If you need more information, you are always encouraged to call one of our Heat treat Furnace specialists, that are happy to answer your questions with no obligation.