Varian M-4 NRC Rebuilt 4-Inch Diffusion Vacuum Pump Rebuilt Refurbished
The Varian M-4 Diffusion Pump belongs to a family of pumps designed to combine high performance and unusually low cost when used alone or with matching components. The backstreaming rate of the M-4 pump is less than 0.0001 Mg/cm2/min., five times better that other diffusion pumps. As a result of this superior performance, it is often possible to use the M-4 without traps or baffles. However, when these components are added, the degree of cleanliness at the inlet of the topmost component is greater than that possible with other pumping systems. The standard patented cold cap which intercepts over 98% of backstreaming vapor, has been redesigned to keep it colder by more efficient heat transfer, and it is easier to install and maintain. The M-4 pump has full thermostatic protection against inadequate cooling water, low pump fluid, or inoperative forepump.The heat and electrical components were replaced where needed and they have been repainted. Inlet Flange is 4 inch ASA.