medicalgassupply-pipelinesandcylinders-110624152551-phpapp02

7/27/2019 medicalgassupply-pipelinesandcylinders-110624152551-phpapp02

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MEDICAL GAS SUPLY:CYLINDERS & PIPELINE

PRESENTED BY :DR. SAURAV


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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


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Different cylinder valve


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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


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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


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PRESSURE RELIEF DEVICES

acts when excessive pressure is build up.

types :

Rupture disc, Fusible plug

combination of both


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PRESSURE RELIEF VALVE

recluse or prevent

discharge of the

cylinder contents after

normal pressure havebeen restored.


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CONICAL

DEPRESSION

receives the retaining

screw of the yoke.


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NONINTERCHANGEBLE

SAFTEY SYSTEMS

PIN INDEX SAFTEY

SYSTEM


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PIN INDEX SYSTEM

OXYGEN 2,5

NITROUS OXIDE 3,5

CYCLOPROPANE 3,6

AIR 1,5

NITROGEN 1,4

NITROUS+OXYGEN 7


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Valve outlet connection for

large cylinders


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SIZE OF CYLINDERS

Cylinder classified using a letter code

A type cylinders are smallest

SIZE E is the cylinder most commonly used


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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 x26

14 625 1590 660 1590

M 7 x

43

63 2850 7570 3450 7570

G 8 1/2 97 5050 12300 13800


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CONTENTS AND PRESSURE


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CONTENT AND PRESURE


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TESTING

Tensile test

Strips are cut longitudinally from the cylinder and stretched untilthey elongated The yield point should not be less than15 tons persquare inch

Flattening test One cylinder is kept between two compression blocks and then

oressure is applied to flatten it til distance of becomes six timesthe thickness of walls.

Impact test

Three longitudinal and three transverse strips from a finishedcylinder are taken and struck by a mechanical hammer .Themean energy needed to produce a crack should not be less than5 feet lb for tranverse strip and 10 ft lb for longitudinal strip


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Bend test

A ring of 25 mm width is cut from that cylinder andequally divided into four strips.each strip is than bent

inward until the inner edge are apart not greaterthan the diameter of the strip. The approved cylindershould 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 is236.2kgf/cm this test also determines wether it isleak proof or not


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FILLING

DOT,s regulation limiting the amount of a gas cylindermay contain

The pressure in a filled cylinder at 21.c may notexceed the service pressure marked

The pressure in the cylinder at 55.c may not exceed1.25 times the maximum permitted filling pressure at21.c

In case of liquefied gas , the maximum amount ofgas allowed to be filled is defined by filling density .

The filling density is the percent ratio of the weightof gas in cylinder to the weight of water the cylinderwould hold at 16.c


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COLOR OF CYLINDER

GAS USA INTERNATION

AL

oxygen Green White

Carbon dioxide Gray Gray

Nitrous oxide Blue Blue

helium Brown Brown

Nitrogen Black Black

air Yellow White & black


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MARKING ON THE

CYLINDERS

DOT and TC regulation requires followingspecific marking on cylinders :

DOT and TC specification number to indicate

the type of material used in manufacture ofthe cylinder

Service pressure of the cylinder in pound persquare inch

Serial number and identifying symbol of thepurchaser , user or manufacturer


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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


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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


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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


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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 pinon yoke may not extrude far enough to

engage mating whole or safety pin index


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A cylinder valve should be opened slowly,because if gases passes quickly into thespace between valve and the yoke or the

regulator , the rapid recompression in thisspace will generate large amount of heat.because there is no space for dissipation ofheat , this constitutes an adiabatic process.

Particle of dust, grease, etc present in thatspace may be ignited by the heat causing aflash fire or explosion.


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STORAGE

A definite area should be designed to store thecylinders

The storage area should be clean , cool and madeof fire resistant materials with adequate ventilation

Cylinder containing flammable gases should not bestored in an enclosure containing oxidizing gas

Combustible material should not be kept nearcylinder containing oxygen or nitrous

Small cylinders are best stored upright orhorizontally in bins or racks

There should be a system of inventory for bothempty and full cylinders


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HAZARDS

incorrect cylinders

Incorrect content

Incorrect valve

Damaged Valve

Suffocation

Fires

Explosion Contamination of cylinder content

Theft of nitrous oxide


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MEDICAL GAS PIPELINE

SYSTEMS


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COMPONENT

A central supply

Piping extending to location where gassupply is required

Terminal point


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Manifolded cylinders


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Source of gases

Oxygen

Gaseous supply( G or H type )

Liquid supply ( when large amount of oxygenis required , it is less expensive and more

convenient to store )

Oxygen concentrator

Nitrous oxide

Large cylinder manifold


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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 dewpoint of less than 4 c


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Manifolded cylinders with a proportioning

device which mixes gases from oxygen and

nitrogen cylinders

Motor driven air compressor

Carbon dioxide

High pressure cylinder


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PIPED DISTRIBUTION SYSTEM

Main lines pipe connecting the source to riseror 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 outerdiameter and that of other gases is 3/8 inchdiameter


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TERMINAL UNITS

COMPONENTS

Base block

This the part of the terminal unit that attached

to the pipeline distribution system

Primary valve( automatic shut off valve, selfsealing device, primary check valve)

opens and allows gas to flow when maleprobe is inserted and closes automaticallywhen the connection is broken


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Secondary valve

( shut off valve, maintenance valve)

is designed to shut off when primary valve isremoved for cleaning or servicing

GAS SPECIFIC CONNECTION


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GAS SPECIFIC CONNECTION

POINT( SOCKET ASSEMBLY)

two types ---

Threaded DIAMETER INDEX SAFTEY

SYSTEM

PROPRIETARY QUICK CONNECTOR

DIAMETER INDEX SAFETY


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DIAMETER INDEX SAFETY

SYSTEM


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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


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Hoses

connection between terminal units and the

ventilator or anaesthesia machine

color coded and have the name and

chemical symbol of the gas


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Types of terminal unit

Wall mounted

Ceiling mounted


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Wall mounted terminal unit

T ti f di l


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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 beblown 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 ismaintained and each join has been checked forleakage


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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


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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

PROBLEMS WITH THE PIPING


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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


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High pressure

Causes, most commonly failure of regulator,

ice formation

Alarm problems

Failure, absence or disconnection

False alarm.


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Contamination of gases

can be serious problem when a new pipeline

is opened

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