Since the arc heating engine is operated at a high temperature and the working time may be longer, this imposes requirements on the high temperature resistance of the selected material. When the engine is working stably, the arc to be maintained between the cathode and the anode should be stable. It is not allowed to generate arcs at any part outside the anode and cathode. This will not only affect the working arc, reduce the specific impulse and efficiency of the engine, but also the high-temperature arc that should not be generated. It causes serious damage, so it requires not only a reasonable internal structure of the engine, but also a material that plays an insulating role in a high-temperature environment. Especially under vacuum conditions, the design with stable performance under the standard atmospheric pressure will happen many times. The problem, so be sure to pay attention to insulation protection.

In the vacuum system, due to the huge pressure difference between the inside and outside of the engine, the various components of the engine must ensure the airtightness of the interface at the time of installation. Otherwise, it will easily cause leakage, reduce the performance of the engine, and endanger the reliability and stability of the engine operation. Because the energy carried by a unit mass of propellant is reduced, a high temperature resistant sealing material is required. In this experiment, flexible graphite is used as a sealing material. Due to the conductivity of the flexible graphite, care must be taken to avoid arcing with the cathode. And a short circuit of the cathode and anode occurs. The upper part mainly plays the role of gas sealing. The interior is equipped with pyrophyllite with a flexible graphite seal. It is mainly used for the sealing and insulation of the shell and the cathode. The upper nut mainly plays the role of fastening. The selected material is stainless steel.