Logically, you should get something that will seal a high temperature but that sounds somewhat meaningless. First of all, how high is a high temperature and, do you actually seal temperature into something? I suppose, in theory, when you close an oven door you are sealing the heat inside but, isn’t that really a question of making sure that the gas (air) inside the oven does not escape to the outside atmosphere. In which case, that length of woven tape that is often fitted to the inside of a domestic oven door is acting as an air sealant and the high temperature is whatever you have set on the oven’s thermostat.
Expanding This Theory Into Industry
Door or lid seals. Whether called ovens, autoclaves, reactors or even furnaces there are many industrial processes that require a gas or a liquid to be heated to elevated temperatures within a closed vessel. Some of these operate at temperatures and pressures that are so high that the openings into the vessel can only be sealed by bolted joints using high-tech gaskets. Other vessels, such as a tar boiler for example, have very little internal pressure and are not really all that hot. For these, a High Temperature Sealant Tape can be used to keep the contents inside the vessel and stop the outside elements from entering the vessel.
Thread Sealants. When, for example one piece of pipe is joined to another by a screwed connection there is very good chance that whatever is flowing through the pipe will escape through the minute clearances in the treaded connection. Old time plumbers used greasy string around the male thread to solve this problem on low pressure water connections but such an approach would not work on high pressures and elevated temperatures. PTFE (e.g. DuPont’s Teflon®) can be used as a thread tape or compound paste/putty sealant up to around 400° F.
Form In Place Gasket Sealants. These are compounds that you squeeze out of a tube to cover an area on one component that is to be placed alongside another component and, when bolted together, contain fluid within an open space between the two components.RTV silicone sealant is perhaps the best known and most of them can be used up to 400° F. However, specially modified (by the inclusion of copper for example) grades have an upper limit of 700° F making them more deserving of the name High Temperature Sealant.
There is a veritable host of products that could be called a high tempreture sealants and you will find a good selection of them at Engineered Materials Inc. Take a look at their website at engineeredmaterialsinc.com to see how they can help you.
