Edwards offers a range of oils, ULTRAGRADE™ Performance 15, 19, 20 and 70, which result from a new process. Most manufacturers use a solvent refining process, whereas these oils are produced by a unique hydrotreating process. This process eliminates nitrogen, sulphur and oxygen and the aromatic hydrocarbons, leaving a clear base stock essentially free of impurities. When combined with additives, the ULTRAGRADE™ Performance oils give improved vacuum performance, thermal and oxidation stability and rust inhibition. The anti-oxidants included in the oils enable the pump to withstand high operating temperatures without oil degradation, so extending intervals between oil changes. ULTRAGRADE™ Performance oils are the best choice for large pumps used in heavy-duty, cycling applications.