The modern day Bodok seal is a specialised washer that has the crucial role of ensuring an air-tight seal between the regulator of an anaesthetic machine and a gas cylinder. It was introduced into anaesthetic machines along with the pin index safety system during the 1950s.

Attachment and detachment of a gas cylinder to the anaesthetic machine leads to constant wear and tear, due in part to gaseous compression and expansion. (Adiabatic effects in rapidly expanding compressed gases can generate very high temperatures, up to 1000° Celsius.) Prior to the introduction of the Bodok seal, the traditional fibre washer would frequently splay and adhere to the regulator and thus require the use of a good pair of pliers and some considerable force.

The Bodok seal consists of a neoprene washer with a peripheral magnesium metal ring which prevents additional splaying of the washer. It is noncombustible, and very resistant to explosions, fire, oils, petrol, sunlight, ozone and high heat.

External links

• Bodok seal note (See Historical Forum following Nerve Plexus article)