Medical Gas and Vacuum Systems
Plumbing Systems and Design 22006; Vol. 5: No. 1
This continuing education article on medical gas and vacuum systems begins with a system designer?s checklist, tailored to help meet specific client needs and with steps for new construction and for additions to existing facilities. A primary consideration is to locate and count the number of inlet/outlets (stations). Codes do not mandate the number to be provided. Guidance is available in American Institute of Architects, National Fire Protection Association, and ASPE publications. Flow rates are dealt with next. Flow rates and diversity factors vary for individual stations in each medical gas system, and system use also varies as a function of several factors. Tables present outlet rating charts for medical gas-vacuum piping systems to assist in calculations. Medical-gas stations are often included along with other services in patient head-wall systems. These are sometimes the provenience of the plumbing engineer and sometimes included in other sections of the specifications. Other types of medical gas dispensing equipment include special ceiling-mounted medical gas outlets and high-pressure nitrogen dispensing equipment, often used to power surgical tools and other support equipment. An example detailing ceiling outlets, surgical ceiling columns, surgical gas tracks, and articulating ceiling-service centers used to supply medical gas to surgery rooms is presented. Medical gas storage is the last major topic. The designer must determine storage capacity, pipe sizing, and location(s) for the source. Sources for oxygen, nitrous oxide, and medical compressed air have unique characteristics, and each of these gases is detailed separately as regards storage. Each system consists of primary and reserve storage. Oxygen may be sourced in a bulk system or a cylinder-manifold-supply system. Each has special considerations. Nitrous oxide is most generally sourced in a cylinder-manifold system, with many of the same consideration as for oxygen cylinder-manifold supply. System demands for nitrous oxide can be more difficult to calculate. In addition to a high-pressure cylinder-manifold system, medical compressed air may be generated on site from atmospheric air with a special compressor system. Compressor types designed specifically for use in medical applications include the reciprocating and rotary screw (positive-displacement) types and the centrifugal (dynamic) type. These compressor types are rated differently; equations and conversion factors are presented so that more direct comparisons among them can be made.
Available at : ASPE Publications