A: Combustion systems should be inspected at least annually to be NFPA compliant. Thermal processes do not typically directly control part temperature; but rather, they often control the environment the part is in. As such, control of all other process conditions (residence time, fixturing, moisture content, temperature, coating content, atmosphere, air exchanges, etc.) are an indirect means to ensure repeatable thermal processing. A schedule of regular inspections ensures thermal processes operate safely and reliably: detecting issues before dangerous conditions arise, or non-conforming parts are produced.