1. MEDICAL GAS SUPLY: CYLINDERS & PIPELINE PRESENTED BY
:DR. SAURAV
2. COMPONENT OF MEDICAL GAS CYLINDRES
BODY
constructed of steel ,
alloys added for strength.
Aluminum cylinders are MRI compatible
VALVE
filled and discharged through a valve
attached to the neck,
made of bronze or brass
3. Different cylinder valve
4.
5.
Packed valve :
stem is sealed by resilient packing such as Teflon ,
Diaphragm valve :
a diaphragm separated the stem from the seat.
. Advantages:
# can be used fully using a one half to three quarters
turn
# less likely to leak
# No stem leakage
6.
7.
8.
PORT
the point to exit for the gas.
STEM
closes the valve by sealing against the seat. When the valve is
opened, the stem moves upward, allowing the gas to flow to the
port
9. PRESSURE RELIEF DEVICES
acts when excessive pressure is build up.
types :
Rupture disc,
Fusible plug
combination of both
10. PRESSURE RELIEF VALVE
recluse or prevent discharge of the cylinder contents after
normal pressure have been restored.
11.
CONICAL DEPRESSION
receives the retaining screw of the yoke.
12. NONINTERCHANGEBLE SAFTEY SYSTEMS
PIN INDEX SAFTEY SYSTEM
13. PIN INDEX SYSTEM OXYGEN 2,5 NITROUS OXIDE 3,5 CYCLOPROPANE
3,6 AIR 1,5 NITROGEN 1,4 NITROUS+OXYGEN 7
14. Valve outlet connection for large cylinders
15. SIZE OF CYLINDERS
Cylinder classified using a letter code
A type cylinders are smallest
SIZE E is the cylinder most commonly used
16. TYPICAL MEDICAL GAS CYLINDRES, VOLUMES, WEIGHT cylinder
size dimension weight (ib) Air CO2 oxygen Nitrous oxide B 3 1/2 x
13 5 370 200 D 4 1/2 x 17 11 375 940 400 940 E 41/4 x 26 14 625
1590 660 1590 M 7 x 43 63 2850 7570 3450 7570 G 8 1/2 x 51 97 5050
12300 13800
17. CONTENTS AND PRESSURE
18. CONTENT AND PRESURE
19. TESTING
Tensile test
Strips are cut longitudinally from the cylinder and stretched
until they elongated The yield point should not be less than15 tons
per square inch
Flattening test
One cylinder is kept between two compression blocks and then
oressure is applied to flatten it til distance of becomes six times
the thickness of walls.
Impact test
Three longitudinal and three transverse strips from a finished
cylinder are taken and struck by a mechanical hammer .The mean
energy needed to produce a crack should not be less than 5 feet lb
for tranverse strip and 10 ft lb for longitudinal strip
20.
Bend test
A ring of 25 mm width is cut from that cylinder and equally
divided into four strips.each strip is than bent inward until the
inner edge are apart not greater than the diameter of the strip.
The approved cylinder should not develop any crack
Hydraulic test or pressure test
The test is usually done by the water jacket method. here the
proof pressure applied inside is 236.2kgf/cm this test also
determines wether it is leak proof or not
21. FILLING
DOT,s regulation limiting the amount of a gas cylinder may
contain
The pressure in a filled cylinder at 21.c may not exceed the
service pressure marked
The pressure in the cylinder at 55.c may not exceed 1.25 times
the maximum permitted filling pressure at 21.c
In case of liquefied gas , the maximum amount of gas allowed to
be filled is defined by filling density .
The filling density is the percent ratio of the weight of gas
in cylinder to the weight of water the cylinder would hold at
16.c
22. COLOR OF CYLINDER GAS USA INTERNATIONAL oxygen Green White
Carbon dioxide Gray Gray Nitrous oxide Blue Blue helium Brown Brown
Nitrogen Black Black air Yellow White & black
23. MARKING ON THE CYLINDERS
DOT and TC regulation requires following specific marking on
cylinders :
DOT and TC specification number to indicate the type of
material used in manufacture of the cylinder
Service pressure of the cylinder in pound per square inch
Serial number and identifying symbol of the purchaser , user or
manufacturer
24. MARKING ON THE CYLINDERS
The initial qualifying test date with an identifying mark for
the testing facility
Retest date and testing facility
A five pointed star stamped after the most recent test
date
A plus sign if cylinder can be charged up to 10% in excess of
the marked service pressure
25. RULES FOR SAFE USE OF CYLINDERS
Cylinders should be handled only by trained person
Cylinder valves, regulator. Gauges, and fitting should never
come into contact of oils , greases , organic lubricants etc
Cylinders should not be subjected to extreme of
temperatures
Connection to piping , regulator, and other equipments should
always be kept tight to prevent leakage
26. RULES FOR SAFE USE OF CYLINDERS
No part of the cylinders should be tainted , painted or
modified by users
A cylinder should never come into contact of electricity
Before use ,cylinder should be identified by the label. The
color of the cylinder should not be relied upon for
identification
Only DOT or ICC approved cylinder should be used
A pressure regulator should always be used
27.
Before any fitting is applied to cylinder valve , the valve
should be opened slowly and briefly to remove dust or any other
particle ( cracking)
A sealing washer or gasket in good condition should always be
used with small cylinder valve . If more than one seal is used the
pin on yoke may not extrude far enough to engage mating whole or
safety pin index
28.
A cylinder valve should be opened slowly ,because if gases
passes quickly into the space between valve and the yoke or the
regulator , the rapid recompression in this space will generate
large amount of heat .because there is no space for dissipation of
heat , this constitutes an adiabatic process. Particle of dust,
grease, etc present in that space may be ignited by the heat
causing a flash fire or explosion.
29. STORAGE
A definite area should be designed to store the cylinders
The storage area should be clean , cool and made of fire
resistant materials with adequate ventilation
Cylinder containing flammable gases should not be stored in an
enclosure containing oxidizing gas
Combustible material should not be kept near cylinder
containing oxygen or nitrous
Small cylinders are best stored upright or horizontally in bins
or racks
There should be a system of inventory for both empty and full
cylinders
30. HAZARDS
incorrect cylinders
Incorrect content
Incorrect valve
Damaged Valve
Suffocation
Fires
Explosion
Contamination of cylinder content
Theft of nitrous oxide
31.
MEDICAL GAS PIPELINE SYSTEMS
32.
COMPONENT
A central supply
Piping extending to location where gas supply is required
Terminal point
33.
34. Manifolded cylinders
35. Source of gases
Oxygen
Gaseous supply( G or H type )
Liquid supply ( when large amount of oxygen is required , it is
less expensive and more convenient to store )
Oxygen concentrator
Nitrous oxide
Large cylinder manifold
36.
Medical air
Definition : It is defined by NFPA as , regardless its sources,
has no detectable liquid hydrocarbon, less than 25 ppm gaseous
hydrocarbon , less than 5mg/m3 of particulates of 1 micron size or
greater at normal atmospheric pressure and a dew point of less than
4 c
37.
Manifolded cylinders with a proportioning device which mixes
gases from oxygen and nitrogen cylinders
Motor driven air compressor
Carbon dioxide
High pressure cylinder
38. PIPED DISTRIBUTION SYSTEM
Main lines pipe connecting the source to riser or branches
lines or both
Risers vertical pipe line connecting the main lines with branch
lines at various levels
Branch line that service a room or rooms
Pipes are made of copper
Oxygen pipe lines have inch outer diameter and that of other
gases is 3/8 inch diameter
39. TERMINAL UNITS
COMPONENTS
Base block
This the part of the terminal unit that attached to the
pipeline distribution system
opens and allows gas to flow when male probe is inserted and
closes automatically when the connection is broken
40.
Secondary valve
( shut off valve, maintenance valve)
is designed to shut off when primary valve is removed for
cleaning or servicing
41. GAS SPECIFIC CONNECTION POINT( SOCKET ASSEMBLY)
two types ---
Threaded DIAMETER INDEX SAFTEY SYSTEM
PROPRIETARY QUICK CONNECTOR
42. DIAMETER INDEX SAFETY SYSTEM
43.
QUICK CONNECTOR
Allows apparatuses to be connected or disconnected by a single
action
Each quick connector consist of a pair of gas specific male and
female part
A releasable spring mechanism locks the components
together
44.
Hoses
connection between terminal units and the ventilator or
anaesthesia machine
color coded and have the name and chemical symbol of the
gas
45.
Types of terminal unit
Wall mounted
Ceiling mounted
46. Wall mounted terminal unit
47. Testing of medical gas distributing system
Initial test
Blow down test
After the pipelines have been installed , but before the
installation of terminal units, the line must be blown clear using
oil free dry nitrogen
Initial pressure test
Each section of piping system must be subjected to 1.5 times of
working pressure ( minimum1034 kpa) with oil free nitrogen with
source valve closed. It is maintained and each join has been
checked for leakage
48.
standing pressure test
after all the component of the system have been installed , the
entire system is subjected to 24 hours standing pressure at 20%
above the normal operating line pressure
piping purge test
to remove particulate matter , intermittent purging is done in
every outlet ,until no discoloration on a white cloth held over the
outlet
test for cross connection
to ensure that gas delivered at each terminal is that shown on
the outlet label. One gas system is tested at a time
49.
out flow test
to ensure that oxygen , nitrogen, and air outlet deliver
100L/min without a pressure drop of no more than 35 kpa at a static
pressure of 345kpa
alarm test
piping purity test
50.
Operational pressure test
Piping system for gases other than nitrogen must maintain the
pressure at 345kpa 35 .piping system of nitrogen must maintain a
pressure at 1100 kpa
Medical air purity test
Air source must be analyzed for dew point, carbon monoxide,
gaseous hydrocarbon etc
51. PROBLEMS WITH THE PIPING SYSTEM
Inadequate pressure
Causes: damage of any part, compressor failure, leaks, closure
off shut off valve , obstruction, kinking of hose etc
Leaks
May hazardous if oxidizing gases are allowed accumulate in a
closed room
52.
High pressure
Causes, most commonly failure of regulator, ice formation
Alarm problems
Failure, absence or disconnection
False alarm.
53.
Contamination of gases
can be serious problem when a new pipeline is opened
