Oil seals are devices that maintain the integrity and efficiency of various machinery and equipment. Their main role is to prevent the leakage of lubricants and fluids while also protecting against the intrusion of harmful contaminants. Known as rotary shaft seals or lip seals in numerous settings, the purpose of oil seals is to seal the gaps between moving and stationary components in machinery. As such, they are primarily designed to retain lubricants and prevent the escape of fluids, such as oil or grease, while keeping out dirt, dust, and moisture.

By driving various industrial operations, turbines play a vital role in converting numerous forms of energy into mechanical power. In particular, axial flow turbines are a type known for their efficient energy conversion, as well as their contribution to the aviation and power generation industries. Because of this, these machines are extensively used in applications involving turbojet engines, steam turbines, and gas turbines. 

While modern aircraft now typically rely on powerful gas turbine engines to create the thrust and power necessary for flight, there are still countless models that feature more conventional assemblies like reciprocating engines and propeller blades. With this pair, power from combusted fuel can be harnessed by propeller assemblies to create a forward thrusting force, allowing the aircraft to overcome drag for movement and flight. 

Boilers are a common feature of many spaces, serving to heat fluids within a closed vessel to boil, heat, or vaporize them. While many boilers perform the same general role, the use of the end product may differ as heated fluids are taken for cooking, water heating, sanitation, central heating, power generation, and other applications. 

Since the debut of commercially available powered aircraft, countless advancements have been made to improve flight. As compared to the original models used in the early days of aviation, many aircraft are now fitted with powerful gas turbine engines that allow them to traverse farther distances, higher altitudes, and so much more. While gas turbine engines have become the standard of the current era, there are still many aircraft models that make use of conventional propeller blade assemblies.