This series of stirred reactors has been designed for users who need higher operating pressures than the 1900 to 2900 psi offered by the General Purpose Reactors, but do not require the high operating temperatures provided by the Series 4570 High Pressure, High Temperature Reactors. The 4540 series reactors offer working pressures to 5000 psi (345 bar) at temperatures to 350 °C.