The ING site has its own plant which supplies liquid nitrogen for the ING telescopes either in large 75 litre pressure vessel cryostats, or in smaller, more portable 25 litre cryostats. The plant has ample capacity to supply liquid nitrogen for most uses. However if a high usage is expected, it is worth warning RGO staff ahead of time. Filling the instrument cryostats is usually done with a self--pressurising or electric pump via a plastic hose.
Liquid helium is difficult to obtain since it has to be supplied from mainland Spain via Tenerife. Users requiring liquid helium should make their own enquiries and arrange shipment.
For cooling instruments with photomultipliers or image tubes there are several Churchill coolers, model 10/CTC HG. The WHT and INT each have two cooling units, the extra one intended as a spare. The spare units are avaliable for user supplied instruments. These coolers use a pumped glycol--water coolant with the temperature adjustable from 0 to 20 C (WHT units) and --20 to 20 C (INT). The coolers have a capacity of 3 kW. The coolant is fed through 16 mm plastic hose with quick connect couplings.
On the INT, there is a standard 80 psi compressed air supply which is fed through a drier and filter before connection to the telescope. The INT also has a bottled supply of dry notrogen. These gas supplies are terminated at the Cassegrain and prime foci in standard type quick connects. The JKT gas supply is similar to the INT, with cleaned compressed air and dry nitrogen avaliable at the Cassegrain focus.
At present the WHT has a dry nitrogen gas supply to the telescope. This supply comes from a pressurised liquid nitrogen cryostat with a backup system of bottled nitrogen. The supply pressure is set at 80 psi (6 bar). The supply outlets at Cassegrain, Nasymth and prime foci are Swagelok Pat DOC4 Key 1 quick connects. The WHT Cassegrain focus also has a pressure regulator multi--outlet manifold with multiple miniature quick connects. This gas supply system has a limited capacity, so care should be taken when using it for purposes such as instrument flushing to avoid excessive consumption.