23 mL, 250 °C, 5000 & 3300 psig
The 4746 is a High Pressure Acid Digestion Vessel with a 23 mL, A255AC PTFE Cup and Cover in a strong outer body which can be made either of stainless steel or nickel. The 4746 stainless vessel is intended for use with nitric, sulfuric or other oxidizing acids, offering best resistance to any acid vapors which might migrate through the PTFE cup under high pressures. The 4747 Vessel with a nickel body is to be used with HCl, HF and other reducing acids. Working pressures up to 5000 psi and temperatures to 275 °C can be handled in the 4746 stainless vessel, but pressures in the 4747 nickel vessel must be limited to 3300 psi due to the lower physical strength of nickel. The 4746 stainless vessel has a safety blow-off disc which will release through a passage in the bottom of the vessel. The nickel vessel does not have a blow-out passage since reactions with reducing acids are not potentially explosive.
These vessels were developed initially for dissolving nuclear fuel samples but many other applications with refractory or highly active materials are indicated. Their heavy construction will be reassuring when working with mixtures which are potentially explosive or whose behavior is unknown and therefore must be handled with care.
The extreme pressures developed in these vessels will tend to deform the PTFE cup, making it difficult to remove the cup from the vessel. To overcome this problem, Parr offers an A263AC Spanner Jack that will push the cup out of the vessel with a smooth, uniform pressure without damaging the cup. This spanner jack is not included with the vessel and must be ordered separately.