Presentation by Philip Gallimore Media Representative for IOSH North Staffs and South Cheshire District Feb 2014

Transcription

1 Safety of Gas Cylinders Presentation by Philip Gallimore Media Representative for IOSH North Staffs and South Cheshire District Feb

2 Some gases you may know Air gases: oxygen, nitrogen and argon Rare gases: helium, krypton, xenon and neon Hydrogen, carbon monoxide, carbon dioxide and nitrous oxide Acetylene, methane and propane

3 Production of Gases Air gases (oxygen, nitrogen and argon) are mostly produced at cryogenic temperature in Air Separation Units. In smaller quantities and lower qualities other technologies (Pressure Swing Adsorption or membranes) are used to produce oxygen and nitrogen at the customer sites.

4 Future innovations- Healthier Life: food preservation, hygiene, new medical gases and aerosol therapy Communicating World: electronics and semiconductors, optoelectronics Sustainable Environment: clean Sustainable Environment: clean energies, waste control, more efficient processes

5 Supply by cylinders Smaller quantities of gases are supplied in gas or liquid cylinders. Around 100 million cylinders are in circulation worldwide.

6 Gases Gases in Cylinders Over 130 individual gases and liquids are packaged in cylinders Gas mixtures Infinite variety of mixtures varying from PPB to percent concentrations Components from 2 to >50

7 Three Types of Packaged Gases Gases are packaged into cylinders in a variety of ways Compressed Gas ( e.g. Nitrogen) Liquid and gas ( e.g. Carbon Dioxide) Gas in solution ( Acetylene Only)

8 Transport classes for gases is simplest: Gases are all UN class 2 substances FLAMMABLE 2.1 NON-FLAMMABLE 2.2 TOXIC / CORROSIVE 2.3

9 Flammable Gases Acetylene Hydrogen Propane

10 Non-Flammable Gases Nitrogen Argon Helium Carbon Dioxide Oxygen

11 Toxic Gases Chlorine Hydrogen Chloride Ammonia

12 Hazards relating to Cylinder Gases Weight Pressure Gas properties

13 Cylinder Weight Cylinder construction means that cylinders are heavy even when empty!

14 Construction of Gas Cylinders High Pressure Cylinders Low Pressure Cylinders Acetylene and LPG

15 Handling - Moving Cylinders Lift by hand using valve guard (10 litre cylinders) Roll cylinder on solid clean floor (50 litre cylinder) Churn by valve guard (110 litre cylinders)

16 Ideally use a Cylinder Trolley Secure Cylinder in trolley with chain, strap or bar

17 Manual Handling Hazards - Traps Falling Cylinders Pressure Never attempt to catch a falling cylinder WEAR

18 Cylinder Identification Because the colours can be confusing The only way to identify a gas cylinder is by its label

19 Marking and Labelling of Cylinders Hazard Label Gas UN Number Mass of cylinder and Tare weight Date of next Inspection

20 Pressure is the Hazard which is common to all Compressed Gases Pressure is stored energy Some units of Pressure are Pounds per Square Inch or PSI Bar Atmospheric Pressure is the pressure on the earth created by the gases above us Modern cylinders typically are supplied with 200bar pressure and some are 300bar

21

22 Valve - used to control gas into and out of Cylinder CO2 Bursting Disc Relief Valve on LPG Hole reduced to 4mm

23 Using the gas - Connections Seals on Dome Seals on Washer Left Hand thread for Flammable Gases -note cuts in nut Right Hand thread for Non Flammable Gases Make connections hand tight and then secure with spanner Ensure connecting pipe work is rated for pressure required

24 Pressure Regulator Some cylinders have the pressure regulator built into the valve so you don t need a separate regulator

25 Summary of Use Check Label Access the valve outlet Check sealing faces for dirt, oil, damage Fit Pressure Regulator (finger tight then 1 / 4-1 / 2 turn with spanner)

26 Welding Set up

27 Welding Gases Oxygen - never allow oil or grease to come into contact with valve outlet or fittings. - never use equipment not cleaned or designed for oxygen service. Acetylene - if the cylinder is involved in a fire or has suffered a flashback and NO flashback arrestor fitted then the cylinder could suffer acetylene decomposition. - if an acetylene cylinder becomes hot or starts to vibrate then evacuate the building immediately. - call the Fire Brigade they have procedures for dealing with acetylene in fires - New requirement that all acetylene cylinders must be fitted with flashback arrestors and non return valves

28 Backfire and Flashback Backfire is when flame burns back into the blowpipe often with a loud bang. Caused by blocked nozzle or holding torch too close to work piece. Remedy switch off and examine nozzle. Flashback is when one gas enters the other hose and then ignites causing damage to the equipment. Caused by incorrect purge of equipment Remedy proper training and the fitting of flashback arrestors.

29 10L CO cylinder explosion

30 Praxair Fire 2005

31 Tyre fire on vehicle carrying LPG cylinders

32 Emergency Procedures All the major Industrial Gases suppliers operate a 24/7 Contact Point in the event that a cylinder is involved in an incident or accident. Please contact Your supplier. 33

33 bcga.co.uk Produces documents for users e.g. RA for oxy ace use Leaflets on carriage etc Go and look for yourself!

34 Thank You The End