These small pressure vessels are a good choice for chemists working with very expensive materials or materials only available in small amounts. They will also appeal to users who wish to minimize the risks associated with hazardous materials or reactions by restricting the reactants or products to a minimum. Use of the Series 4790 vessels also helps minimize the quantities of waste products which may require special disposal procedures. The 4790 vessels are now available in high pressure (5000 psi) or high pressure/high temperature (500 °C) versions.
These micro vessels have been designed to provide as many of the features of the larger vessels as possible in the limited space available. The standard head fittings include a gage, rupture disc, thermocouple, and valves. Optional cooling now available with aluminum block heaters with cooling capability, welded jackets, or cold fingers.
The vessels are offered in both fixed head and moveable head vessel styles with choices of a self sealing O-ring for temperatures up to 225 °C or with FFKM O-ring for temperatures to 300 °C or with a flat PTFE flat gasket for temperatures to 350 °C, or with an FG Flexible Graphite gasket for temperatures to 500 °C with the HP/HT option (for fixed head versions only). A split ring closure is standard.
All three volumes use the same Model 4921 Ceramic Fiber Heater.
These micro vessels can be easily converted from one size to another by simply substituting a larger or smaller cylinder and the corresponding internal fittings. The support system can also be readily adapted to accept any of the vessels from the 4790 Series vessels. The opportunity to modify these small reactors is restricted because of the limited head space available.