Coating is the application of a firmly adhering layer of shapeless material to the surface of a workpiece.
A Pressure/vacuum relief valve Pressure/vacuum relief valve is an umbrella term that includes pressure or vacuum relief valve as well as pressure and vacuum relief valve. coating Coating Coating is the application of a firmly adhering layer of shapeless material to the surface of a workpiece. can be either a single layer or several layers. A distinction is made between chemical, mechanical, thermal and thermomechanical processes, depending on how the coating is applied. The thickness of the coating differs depending on the process and application purpose.