4650 Series High Pressure and High Temperature Vessels are available in volumes of 250, 500, and 1000 mL. These vessels can obtain temperatures up to 600 °C and a maximum pressure of 6000 psi (410 bar). The maximum pressure at maximum temperature is 4200 psi (290 bar) at 600 °C. They come standard with a Split Ring Closure with 8 Cap Screws, and a VGR-T head design that includes Valve, Gage, Rupture Disc, and Thermowell. An additional valve with dip tube can be added.The maximum allowable head openings are seven but this may be limited by the types of fittings required. These vessels are available as either a movable or fixed head design.