Cylinders and Pin Index Flashcards
Oxygen: colour
Black with white shoulders
Carbon dioxide: colour
Grey with grey shoulders
Nitrous oxide: colour
French blue with blue shoulders (will switch to white cylinder with blue shoulders by 2025)
Medical air: colour
Grey with white-black quartered shoulders
Entonox: colour
French blue with white-blue quartered shoulders
Heliox: colour
Brown with white-brown quartered shoulders
Oxygen cylinder: D cylinder capacity
340 L at 137 bar - made of molybdenum steel
Oxygen cylinder: CD cylinder capacity
460 L at 230 bar - made of Kevlar-hooped aluminium
Oxygen cylinder: E cylinder capacity
680 L at 137 bar - made of molybdenum steel
Oxygen cylinder: J cylinder capacity
6800 L at 137 bar - made of molybdenum steel
Schrader Probe: safety
To prevent misconnection to the wrong gas service, the probe for each gas supply has a protruding indexing collar with a unique diameter, which only fits the Schrader socket assembly for the same gas.
Flexible Hose: safety
Colour coded and non-kink. Oxygen = white, nitrous = french blue and medical air = black and white
Non-Interchangeable Screw Threads: connection of hose to anaesthetic machine
This ensures a hose connection specific to each gas service. It comprises a nut and probe. The probe has a unique profile for each gas, which fits only the union on the machine for that gas. The nut has the same diameter and thread for all gas services, but can only be attached to the machine when the probe is engaged. The term NIST is in fact misleading; the screw thread does not determine the unique fit. A one-way valve ensures unidirectional flow.
Bodok seal
Bonded disc (Bo-dok) seals are non-combustible neoprene washers which sit between cylinder head and yoke
Pin-index system
This prevents the accidental connection of a cylinder to the wrong machine yoke. The cylinder valve block bears an arrangement of holes, into which fit pins protruding from the yoke.
