The back pressure regulator consists of a motor-driven heated valve assembly controlled by a microcontroller. The heated valve assembly compensates for cooling that occurs during depressurization and eliminates plugging. The high-strength stainless steel needle and reinforced PEEK seat have a high resistance to erosion and allow stable pressure control over a wide pressure range. A built-in pressure sensor provides closed loop feedback for pressure control. The back pressure regulator can easily be programmed using a hand held controller for stand-alone operation, or by using an RS232 port with software for advanced control features. Thar offers manual back pressure regulators, with 4,000 psi and 10,000 psi, flow up to 200 g/min.