TRAINING REPORT ON SELF CONTAINED BREATHING APPARATUS.docx

TRAINING REPORT ON SELF CONTAINED BREATHING APPARATUS INTRODUCTION SCBA stands for self contained breathing apparatus. It provides breathing air for specific period of time to allow fire fighter to work in oxygen deficient atmosphere SCOPE Scope of this training is to get aware participant about purpose of breathing apparatus, how breathing apparatus works, types of breathing apparatus, safety consideration while doing operation with breathing apparatus, application, limitation and method to wear breathing apparatus in one minute. PURPOSE Purpose of SCBA is to provide breathing air to person for handling emergency condition for specified period for different purpose like save life to unconscious person in emergency area or to isolate process in condition of leakage or fire smoke in imminent danger to health and life condition where oxygen is deficient. Following four condition where respiratory hazard found at fire scene or leakage of gases and other emergency incident.  Oxygen deficiency o Human body requires oxygen to survive below 19.5% of oxygen consider oxygen deficient environment and below 17% oxygen rate body respond by increasing its respiratory rate.  Elevated temperature o Inhalation of heat gas causes damage of lung cells and cause severe health effect.  Smoke o Smoke is combination of unburned carbon, co and co2 is irritating to body and some extent fatal to the respiratory system  Toxic environment o Toxic environment is fatal to respiratory system and cause death to human life. TYPES OF BREATHING APPARATUS  Open circuit breathing apparatus is general purpose available in our plant where breathed air vented outside atmosphere  Close circuit breathing apparatus exhaled air is filtering, cleaning and circulation.

OPERATING PRINCIPLE OF SCBA The self contained open circuit breathing apparatus is equipped with a high pressure compressed air cylinder. This apparatus supplies the user with breathable air from the cylinders carried on his back. The high pressure compressed air contained in the cylinder is reduced to medium pressure by the HP/MP reducer at the first stage. It is reduced then by the second stage demand valve and enters the full face mask at a breathable pressure. The demand valve maintains a slight positive pressure in the mask, whatever the breathing rhythms preventing ambient air from entering the mask. Theoretical duration calculation The volume of air carried is calculated based on the capacity and the filling pressure of the cylinders. One 6 liter of cylinder at 300 bar contains 6x300=1800 liter of air One 6 liter of cylinder at 200 bar contains 6x200=1200 liter of air The air duration depend on quality of air and users consumption The user consumption is low(20liter/min), medium(40liter/minute) and high (100 liter/minute) depends on breathing rhythms. We are having one SCBA set which has capacity of 6 liter and filled at 200 bar so for medium breathing rhythm that can run for 6*200/40= 30 minutes and another one is 6 liter capacity at 300 bar so for medium breathing that can run for 6*300/40=45 minutes CONSTRUCTION OF OPEN CIRCUIT SCBA SCBA has five basic assembly components  Backpack and harness o It is designed to hold air cylinder and provide straps for securing SCBA unit.  Cylinder o Material for SCBA cylinder is steel, aluminum, composite carbon confirm to IS 7285 part II o Cylinder is fitted with open/close valve  Regulator o HP/MP regulator fitted near to cylinder valve and reduce pressure to an average pressure of 7 bar o Second stage pressure regulator or demand valve convert it into atmospheric pressure slight above atmospheric pressure inside mask area  Face piece assembly o Face piece assembly is having full mask equipped with inhalation valve  Working pressure gauge and warning whistle o Working pressure gauge in bar shows the residual pressure in cylinder.

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Personal Alert Safety System (PASS) is effective warning whistle to inform user high pressure drop to 55 bar which means remaining duration is about 10 minutes at an average breathing rhythms.

PROCEDURE TO USE SELF CONTAINED BREATHING APPARATUS General instruction    

Fire fighter must be physically fit. Fire fighter must work in team of two in minimum PASS device must be activated and checked before entering hazardous area If low alarm activated for one fire fighter both team member must exit together.

Step 1: Before wearing SCBA set fully open the cylinder valves, the working pressure gauge must display pressure of 180 bar minimum for 200 bar cylinder and 280 bar minimum for 300 bar cylinders Step2: Open the cylinder valve to pressurize apparatus then close cylinder valve and slowly purge the circuit by pressing on the demand valve by pass buttons. Watch the whistle must start at 55+-5 bars Step3: Donning procedure: Slacken the shoulder strap as much as possible. Put the SCBA on your back by overhead pull method as per training and pull on the strap ends until the apparatus is suspended comfortably between your shoulders. Fasten and tighten the backpack belt, then the chest strap connecting the two shoulder straps. Step4: Before wearing mask open cylinder valve and check cylinder pressure. Wear mask by tightening all harness and tight properly for wearing by mask facing downward. Compressed air breathing apparatus is ready to use. Step5: While operation check time to time pressure and on listening low level alarm leave place immediately. Step6: After operation for removing mask put forward with thumbs on hand harness buckle lugs to loosen and release head harness and gently pull mask and close cylinder valve. Step7: Detach chest strap and belt of backpack, loosen the shoulder strap and remove compressed air breathing apparatus.