Air Pressure Control Valves and Air Pressure Stabilisers

Protecting individual doors

The protection mechanism for individual doors is examined below based upon the assumption that only one door is open at any time. Within the overall supply volumes available it is not possible to provide protection for more than one open door at a time.

Theatre - Exit Bay door open

Double door - Required flow 0.75 m3/s. (Sterile) - (Transitional)

The pressure in the Theatre falls to 3 Pa when this door opens thus causing the stabilisers to the Anaesthetic and in the Scrub to close so diverting all the Theatre supply air across the doorway. In an S.P.S. Prep layout the Theatre has a supply of 0.75 m3/s which is adequate. In a Lay-up Prep layout the Theatre supply is normally only 0.65 m3/s but the Prep is supplying additional air to the Theatre and thus there is sufficient air to achieve protection.