medical gas supply systems Flashcards
bulk systems
Bulk Systems:
Defined by the NFPA as any system with > 20, 000 cubic ft. of gas
Usually liquid O2 systems
Involves an insulated reservoir, vaporizer and tubing (warms liquid O2 to room temperature), pressure reducing valve, and a pressure relief valve
portable systems
Portable liquid systems are usually filled by docking them on a larger liquid oxygen reservoir
Will continuously leak or vent as liquid O2 turns to gas even if not in use
Must keep upright
Duration of oxygen calculated by weight, usually has built in scale but it’s somewhat imprecise
central supply systems
Most large hospitals have two supply systems
Primary source usually a liquid system
Reserve is only used in case of emergency (must contain one day’s supply of O2)
Smaller hospitals use what’s alternating supply system
Consists of primary and secondary sources that alternate function
piping system
Distribute medical gases from the supply systems to the various units in the hospital
As with cylinders and liquid systems they are governed by the NFPA
Must be seamless copper or brass pipe
regulations
Must be labeled every 20 feet
Must have pressure regulating valves that maintain a working pressure of 50 psi
Must have relief valves set 50% higher than working pressure
shutoff valves
Entrance to the hospital
Every riser and at the
Entrance to each zone
Outside each ICU and OR suite
station outlets
Hospital piping connects to station outlets
Either a DISS or quick connect (KISS) connection
regulators
flowmeters- regulates flow
regulator is apressure reducing device- 2200 psi to 50 psi
delivery pressure gauge
usually at 50 psi
inlet pressure gauge
shows actual pressure in cylinder
thorpe tube
Advantages:
A compensated Thorpe tube flowmeter will read accurately even with back pressure in the system
Disadvantages:
Gravity dependant so flowmeter must be perfectly upright
Uncompensated Thorpe tube flowmeters exist but are not used in this region
blender
Blender:
Device that mixes oxygen and air together providing precise gas concentrations
Uses:
Power ventilators
Continuous positive airway press (CPAP)
Precisely controlled O2 therapy
