Proof testing is typically run on parts at a higher RPM than operational speeds but lower than burst speeds to prove the parts are suitable for use. It has three important aspects are suitable for operation: the design, the materials used and the manufacturing processes employed. All critical production parts should be 100% proof tested while less critical parts may only be sample tested. The intention of a proof test is to extract information about the part while maintaining the part in good working order; however, it can burst at any time releasing substantial destructive energy. It is used for the turbine rotor, turbo fans, high-speed fans and turbochargers applications. It will provide evidence that the design, material and process are sufficient. Any flaws that could affect the performance or life will show up more readily when spun at a speed higher than at normal operating speed.
Propane is an energy-rich gas. It is one of the liquefied petroleum gases that are found mixed with natural gas and oil. Propane naturally occurs as a gas. However, at higher pressure or lower temperatures, it becomes a liquid. Propane is 270 times more compact as a liquid than as a gas, so that it is transported and stored in its liquid state. Propane becomes a gas again when a valve is opened to release it from its pressurized container.