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Presented by:

Wajeeha Kiran 2008-chem-51Ambreen Akram 2008-chem-17Sana Arif 2008-chem-47Aiman Fatima 2008-chem43

Safe Use of Cylinder Gases

SynopsisIntroduction to Gas Cylinder SafetyMain causes of AccidentsMain HazardsRules for Safe Working with Gas

CylindersGas RegulatorsFlashback ArrestorsHoses, Piping, Blow Pipes and TorchesAcetylene –unique propertiesHandling Gas Cylinders

Cont’d…….Transporting Gas CylindersSafe StorageCylinder Incident ResponseGas Cylinders Hazards in Your

WorkplaceConclusions

IntroductionCompressed gases used in a variety of

industrial and laboratory situations Compressed gases present a unique hazard.

Depending on the particular gas, there is a potential for simultaneous exposure to both mechanical and chemical hazards

Gases can be:oFlammable or combustible oExplosive oCorrosive oPoisonouso Inert

Common Industrial GasesOxidants support combustion e.g. air &

oxygenInerts do not generally react with other

materials e.g. nitrogen, argon, heliumFlammables when mixed with oxidant and

ignition source will burn e.g. acetylene, hydrogen, propane

Toxics that is toxic in small concentrations e.g. ammonia, chlorine, carbon dioxide

Corrosives react with materials causing reactions e.g. chlorine, sulphur dioxide

Main Causes of Accidents

Inadequate training and supervisionPoor installationPoor maintenanceFaulty equipment or designPoor handlingPoor storage

Main HazardsImpact from the blast of a gas cylinder

explosion or rapid release of compressed gas

Contact with the released gas or fluid(such as chlorine)

Fire resulting from the escape of flammable gas or fluids such as LPG

Impact from falling cylinder

Safe Working with Cylinders

Identification and Properties

Read the label to see what gas you are dealing with and double check that the cylinder/gas is right for the intended use

If the labeling on a cylinder becomes unclear or an attached tag is defaced to the point the contents cannot be identified, the cylinder should be marked "contents unknown" and returned directly to the manufacturer

Cont’d……Never rely on the color of the cylinder for

identification. Color coding is not reliable because cylinder colors may vary with the supplier. Additionally, labels on caps have little value because caps are interchangeable

If there is a mismatch between the colour of a cylinder and the label. Do not use, contact the supplier immediately

Know the properties of the gas (read Material Safety Data Sheets available from your Supervisor)

The cylinder’s contents should be identified at all times as well as the cylinder status (full, empty or in service)

Cont’d……Daily Inspection

Cylinders should be inspected daily and prior to each use for corrosion, leaks, cracks, etc.

Inspection should include the cylinder, piping, safety relief devices, valves, protection caps and stems.

Leaking regulators, cylinder valves or other equipment should be taken out of service.

Cont’d…….Maintenance of cylinders and their valves

or relief devices shall be performed only by trained personnel.

An emergency response plan shall be developed and implemented wherever compressed gas cylinders are used, handled or stored.

Never smoke around compressed gas cylinders.

Gas Cylinder Use

After the regulator is attached, the cylinder valve should be opened just enough to indicate pressure on the regulator gauge (no more than one full turn) and all the connections checked with a soap solution for leaks.

Cont’d……Before a regulator is removed from a cylinder,

the cylinder valve shall be closed and the regulator relieved of gas pressure. The valve cap shall be replaced, the cylinder clearly marked as "empty," and returned to a storage area for pickup by the supplier

Regulators, gauges, hoses and other apparatus shall not be used on gas cylinders having different chemical properties

Valve outlet thread size is different for different products but the same products from different gas suppliers will have the same thread

Gas Cylinder Regulators

A regulator is a device that receives gas at a high pressure and reduces it to a much lower working pressure

Precision instruments must be handled with care to avoid damage

Equipment should display the relevant European/British Standard no.and the pressures up to which it can operate

Leave the pressure adjustment knob fully out when the regulator is not in use

Flashback ArrestorsFlashback is the result of mixture of

fuel gas and oxygen burning within the hose, flame travels and burns its way towards the gas source at great speed, can result in force of explosion in either cylinder

Flashback arrestors must be fitted on both oxygen and fuel gas regulators

If flashback arrestor is dropped/damaged replace immediately

Flashback arrestors should only be used with the gas they are labelled for and the pressure they are designed for

Common reasons for flashback

incorrect purging of hose incorrect gas pressure incorrect nozzle damaged torch valves gas passages blocked within the torch

Hoses Correct hose bore size, pressure rating,

length and colour coding are essential for safety BS EN 559Colours

Blue – oxygen, Red - acetylene and other fuel gases(except LPG)

Black – inert and non combustible gases Orange – Liquified Petroleum Gas Never use equipment while hoses are

wrapped around the cylinders or trolley Length of hose should be suitable for the

task Keep hoses in good condition

Cont’d…….Examine the hose for cracks,

deterioration, damage and test the hose for leaks before use

Do not repair hoses unless you have the skill

Purge hose thoroughly before lighting torch

Do not use copper piping with acetylene hoses as it is potentially explosive

Protect hosing from heat, oil, grease or mechanical damage

PipingPiping

Distribution lines and their outlets should be clearly labeled as to the type of gas contained

Piping systems should be inspected for leaks on a regular basis

Special attention should be given to fittings as well as possible cracks that may have developed

Blow Pipes and TorchesBlow Pipes and TorchesLeaks are a serious hazard as they are

closest to the operatorAlways check condition before use, ensure

tip is free of obstructionSigns of heat damage around the blow pipe

or torch may indicate the equipment has suffered internal damage and is leaking and should be replaced immediately

Replace blow pipe or torch ifoBroken bent or loose gas control valveoBent cutter tubeoBroken of bent cutting oxygen lever

AcetyleneAcetylene has unique propertiesAcetylene gas under excess pressure

becomes unstableCylinders should never be subject to

intense heat or physical impact as the rise in temperature and pressure may cause the acetylene to thermally decompose

The cylinder may appear normal but if it is moved it may detonate with fatal consequences

Handling Gas CylindersHandling Gas Cylinders Wear gloves, protective footwear, eye

protection Correct way to move cylinders is to: keep

upright, secure and with valves uppermost Use mechanical aids such as a trolley where

reasonably practicable All personnel involved should have completed

manual handling training Never transport cylinder with valve and

pressure regulator attached or with the valve open

Never attempt to catch a falling cylinder just get out of the way

Never lift a cylinder by its cap, valve or guard

TransportingTransporting Cylinders Cylinders

If possible carry in open vehicles or trailers If they must be carried in closed vans/cars

ensure good ventilation at all times If the load compartment is not separated

from the driver do not carry toxic gas cylinders (those with a toxic gas label and having yellow as a colour on the cylinder)

Ensure gas cylinders are clearly labelled to show contents and associated hazards

Fit suitable protective valve caps and covers to cylinders

Cont’d…….

Disconnect hoses and regulators from cylinders

Carry propane cylinders upright and do not carry flammable gas cylinders in the same compartment as toxic gas cylinders

Do not smoke while carrying cylinders inside vans/cars

Unload the cylinders as soon as possible and move to a well ventilated storage area

If you are involved in an accident advise, any emergency services involved what gas cylinders are being carried

Safe Storage

It is best to store gas cylinders in the open and on concrete in a fenced compound with some weather protection

In storage areas oxygen cylinders must be stored at least 3 metres away from a fire wall from fuel gases

Protect gas cylinders from external heat sources which may adversely affect their mechanical integrity

Cont’d……. Acetylene and propane must never be

stacked horizontally either in storage or in use

Storage areas with gas cylinders must have more than one exit

Cylinders should be located away from any heat/source of ignition and if possible away from the fire exits, elevators, walkways, building egresses, unprotected platform edges, or in locations where heavy moving objects may strike or fall on them

Cont’d……Storage arrangements should be clearly

described in the emergency planStorage area must have good

housekeeping and adequate warning signs with fire fighting equipment as necessary

CylinderCylinder Incident Response Incident Response If a cylinder is leaking but the leak has

not ignited and it is safe to do so having considered the gases specific properties:

Eliminate all sources of ignition Ensure the valve is closed but do not

over-tighten itPut the cylinder in a safe place that is

well ventilated keep it uprightMark the cylinder as faulty and not to

be used

Cont’d…….Warn everyone in the area of the gas leakInform the supplierEnsure the work area is thoroughly

ventilated before continuing with any work

If a hydrogen cylinder is involved be aware that hydrogen burns with an invisible flame so seek expert assistance

Cont’d……. If a flashback has occurred: Close both blowpipe valves oxygen first Close both cylinder valves Check the temperature of the acetylene cylinder for

thermal decomposition Check the blowpipe has not overheated Check the nozzle is not damaged Open both blowpipe valves oxygen first to vent the

system Unwind the pressure adjustment screw on each

pressure regulator Before starting up again, check the integrity of the

whole system

Cont’d……Nature of hazard will determine

procedure to be appliedCall fire brigadeUse large quantities of water to cool the

cylinders if safe to do so (do not aim high pressure water direct at the cylinders) from a safe location and await the arrival of trained emergency personnel (Emergency plan training should address)

Cont’d…….Remove any cylinders not involved in

fire to safe place, ensure valves are closed if safe to do so

Inform gas supplier, If cylinder contents are unknown, treat

as acetylene

ConclusionsCompressed gases present a unique hazard.

Depending on the particular gas, there is a potential for simultaneous exposure to both mechanical and chemical hazards

Inadequate training and supervisiono poor installationo poor maintenanceo faulty equipment or designo poor handlingo poor storageo inadequately ventilated working conditions

Cont’d…….When working with compressed gases you

need to know the properties of the gas, safe use procedures and what to do when things go wrong

For detailed use of individual gases you should now review the relevant Material Safety data Sheet (MSDS) for each gas used on your site

Always Treat Gas Cylinders with Respect!!! & they will respect u in

return!!!!!.......

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