Gas Test

WELCOME TO AUTHORISED GAS TESTING (AGT) CERTIFICATION COURSE

ADCO

No Smoking Emergency Response Procedures Toilets Courses scheduled to start at 0730 and close 1500 Breaks Prayer time

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get to know bit better. Please

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Name

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Department

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Job

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Experience

SSE (S&T)

other a tell us your:

each

/ Ah Ahm med Ism Ismai aill ± AD ADCO CO - HSED

ADCO

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get to know bit better. Please

Let·s



Name



Department



Job



Experience

SSE (S&T)

other a tell us your:

each

/ Ah Ahm med Ism Ismai aill ± AD ADCO CO - HSED

ADCO

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AUTHORISED GAS TESTING CERTIFICATION AGT TRAINING AND ASSESSMENT        

Mini Minim mum work work expe experi rien ence ce ± 2 years ADCO ex experience ± N/A English Language Rele Relevan vantt cour courses ses requi require red d for for appro approval val ± H2S Awareness Breathing ing Apparat Apparatus us ± Confin Confined ed Space Entry & Basic Breath One day PTWS PTWS cours coursee for AGT AGT + writ writte ten n exam exam (pass marks not less than 80%) Gas Gas Tes Testting ing E ± Lear Learni ning ng is requ requir ired ed (under development) Passin Passing g form formal al trai training ning and holding holding a valid valid certifi certificat catee doesn¶t itself make you eligible to sign PTW. To be auth author oriz ized ed as com compete petent nt you MU MUS ST be assessed by an ADCO ADCO ± AGT, then approved by DH, Area Safety Officer and last approved by Area Manager 3

AUTHORISED GAS TESTING CERTIFICATION

ADCO

REASONS FOR GAS TESTING To determine the presence of gas or vapour in the workplace, to identify which gas(es) or vapour(s) are present and to identify the potential hazards that may arise as a result of its presence. It is mandatory in Hazardous Areas where hot work is performed and when Man Entry into confined spaces is required. SOME LOCATIONS WHERE GAS TESTING IS REQUIRED 

Drilling Rigs  Christmas tree / well-head  Flowlines: Pumps, valves, chokes  Manifolds  Gathering stations  Booster stations

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ADCO

AGT must be familiar with the correct locations of gas sampling, such as:  Pits 

Sumps

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Manholes

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Flanges

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Valves gland/ stem

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Pump Casing.

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Drains

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Sewers

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Cellars

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Christmas tree / well-head / Casings

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Roof Seal of Floating Roof Tank

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Sludges

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Vents, Sample Points, gages, etc«

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AUTHORISED GAS TESTING CERTIFICATION Explosive / Flammable Hazards

ADCO

Hydrocarbon vapors and most of flammable gases in oil industry are heavier than air, so they can be trapped in confined spaces and seek lower levels in the ground as pits and sewers

or gases that build up in a Hazardous Area and Confined Spaces can be ignited by: Vapors

 Welding/ Cutting Torch  Friction  Grinding Sparks  Hot Surfaces  Static Charges  Smoking  Open Flame  Using Mobile Phones  Electrical Short or Arcing  Pyrophoric Materials

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AUTHORISED GAS TESTING CERTIFICATION Explosive / Flammable Hazards (Cont¶d) Some Sources

of Ignition

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ADCO

Oxygen Deficiency or Enrichment What is the normal concentration of oxygen in air? Oxygen deficiency can be caused by the following: Consumption

of oxygen during burning process (combustion reaction) ± e.g. cutting and welding Consumption

of oxygen during bacterial action, as in fermentation

process. Displacement

by inert gas such as nitrogen (inerting or purge with nitrogen), carbon dioxide, argon, and halogenated hydrocarbon, etc. rust

Oxygen enrichment (too much oxygen in the air) is dangerous« Why? Fire Oil

starts much more easily in air with more than 23.5% oxygen.

in the presence of pure oxygen will self ignite. 8

AUTHORISED GAS TESTING CERTIFICATION ADCO

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ADCO

TOXIC GASES - ( measured in p.p.m. every 10000 ppm = 1%) 10,000 ppm = 1% 1000 ppm = 0.1% 100 ppm = 0.01% 10 ppm = 0.001% What 4.3% = ? ppm The oil \ gas industry is usually concerned with H2S. The presence of H2S in hydrocarbon is usually termed as sour crude. H2S has a high toxicity, if you detect its presence in low concentrations during working hrs it is best to evacuate the area, alert others and call for a gas test. 10


ADCO

GAS TESTS MUST BE CARRIED OUT BY AUTHORISED ADCO GAS TESTERS ONLY. The results of all Gas tests must be recorded on the appropriate documentation, SECTION 3 OF A PERMIT: TIME, DATE, RESULTS, INITIALS, GAS TESTER CERT. NO. For tests carried out in Confined Spaces the result must be recorded in the Confined Space Entry Certificate SECTION 3. 11

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AHMED ISMAIL 

01/02 0715 0 0 MS 007

ONE

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12 ADCO 2001

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ADCO

TERMINOLOGY AND DEFINITIONS Some abbreviations are used constantly in the process of gas testing. The abbreviations and chemical properties of the gases and vapours commonly found in the industry must be understood by all concerned.

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AUTHORISED GAS TESTING CERTIFICATION Explosive / Flammable Limits (Cont¶d)

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AUTHORISED GAS TESTING CERTIFICATION Explosive / Flammable Limits (Cont¶d) Flammable Gas/Vapor

(LFL%) LEL%

(UFL%) UEL%

Acetylene

2.5

81

Butane

1.9

8.5

Carbon Monoxide

12.5

74.2

Ethane

3

12.5

Fuel Oil

0.6~ 1.0

5 ~ 5.6

Gas Oil

4.7

33

Hydrogen

4

74.2

Hydrogen Sulfide

4.3

45.5

Kerosene

0.6

5.6

Methane

5.3

13.9

Propane

2.2

9.6

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AUTHOISED GAS TESTING CERTIFICATION

ADCO

RELATIVE DENSITY 

With the exception of Gases such as, METHAN, CARBON MONOXIDE, ETHANE and HYDROGEN, most flammable gases have a density greater than air. This is important because it can result in a layering effect where a flammable mixture is present at one level and not at another. THE HIGHER THE RELATIVE DENSITY THE HEAVIER

THE

density =1.9

SUBSTANCE

e.g.

(H2S)

and

(AIR) density = 1.0 17


ADCO

AUTHORISED GAS TESTING CERTIFICATION ADCO Facial Hair Policy A

respirator, either positive or negative pressure, equipped with facepiece shall not be worn if facial hair comes between the sealing surface of the facepiece and the face or if facial hair interfaces with the exhalation valve operation.

 The

wearer should understand all the risks of respiratory injury or death, which may particularly result when exposed to toxic gases/vapours or to oxygen 19 deficient atmospheres.

ADCO

AUTHORISED GAS TESTING CERTIFICATION ADCO

ADCO Entry without (BA) 

Entry without B.A will not be authorised until all deposits, scale & sludge has been removed, and gas test has been done by Authorised Gas Tester. And the confined space has been certified safe by Area Authority / Issuing Authority Guidelines: ± Oxygen 19.5% to 22.5% volume ± Flammable gas < 5% LEL ± Toxic gas < 10 PPM  If gas tester is required to enter a confined space to get a correct reading then Full B.A. and lifeline is required. Unathorised Entry Kills

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AUTHORISED GAS TESTING CERTIFICATION THE GAS TESTER IS USUALLY FIRST ON THE SCENE. HE MUST TAKE PRECAUTIONS. DO NOT NEGLECT YOUR PERSONAL SAFETY AND THEREFORE THE SAFETY OF OTHERS WHO COME AFTER YOU WHILST DOING GAS TESTS

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ADCO

AUHORISED GAS TESTING CERTIFICATION

ADCO

Gas Testing Practices

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ADCO

Gas Testing Practices  AGT

must be aware of the gases that the instrument can

detect. 

He must also be aware of that the presence of other gases can adversely effect the readings. 

When testing in an area it must be considered that gases may be stratified rather than uniformly mixed, spot checks must be carried out for precise readings. 

Do tests initially, upwind of the worksite and then around a minimum of 5 meter radius of the worksite. All potential sources of release must be tested along with the risk spot. 

Thorough gas testing must be conducted at above head height and at floor level to ensure that gases of different relative densities have the best possible chance of being detected.

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ADCO

Gas Testing Practices Dealing With Suspected Leak AGT

must be aware that any suspected leak must be approached with extreme caution.  Assessment

must be made of the exact location, type of gas, the wind direction and the strength of the wind.  AGT

must take readings whilst approaching the area from an upwind location donning appropriate air breathing apparatus, and PPE. A

safety standby man must be present, in contact with the AGT at all times and holding the AGT¶s lifeline. 

The control room must be notified of all results and kept abreast with the development on site. 24


ADCO

Portable Indicator and Alarm Model MSA 361 

MSA 361 consists of three distinct detection units



The hydrogen sulphide portion of the instrument has a range of 0 ± 50 ppm 

Common toxic gases may be found within the oil and gas industry are H 2S, Chlorine, Carbon Monoxide, etc. 

The toxic sensor used on Model 361doesn¶t detect all toxic gases, so the AGT must be aware that other harmful gases or vapours may be present. 25


ADCO

Portable Indicator and Alarm Model MSA 361 (Cont¶d) The combustible gas detection portion of the instrument has a range of 0 - 100% of the Lower Explosive Limit (LEL) of combustible gas in air. Don¶t depend upon flammability scale to detect toxicity of H2S because it will be toxic at a much lower reading than the % of lower explosive limit (LEL) H2S has a lower explosive limit (LEL) of 43,000 ppm or 4.3% H2S has a TLV of 10ppm - 0.001%. 26


ADCO

Portable Indicator and Alarm Model MSA 361 (Cont¶d)  The Oxygen portion has a range of 0- 25% of Oxygen content.  All portions are calibrated at the factory, combustible gas specifically on Pentane.  Each indicator has its own alarm, but they share a common alarm horn.  The combustible gas indicator alarms at 5% LEL (ADCO adjustment) and 25% LEL (factory)  Oxygen indicator alarms when Oxygen drops to 19.5% or increase above 23%  H2S indicator alarms when concentration reaches 10 pm 27


ADCO

Portable Indicator and Alarm Model MSA 361 (Cont¶d)  MSA ± 361 is powered by rechargeable 4.0 V battery pack which provides 8 to 10 hours of sampling in fullycharged condition.  The battery-powered pump draws the sampled atmosphere into the instrument, where it diffuses into the sensing heads of the combustible gas, hydrogen sulphide and Oxygen portions of the instrument.  Sampling flow rate is 1.2 litres per minute  MSA ± 361 is intrinsically safe for use in classified Hazardous Areas. 28


ADCO

Portable Indicator and Alarm Model MSA 361 (Cont¶d) Pre-checks  Visual inspection of the instrument  Charge of The battery (BATT)  Leak Test (Flow indicator)  Flushing of the instrument with fresh air (in open area)  Function Test (pump works ±displays ± knobs)  Adjusting setting of the instrument in fresh air ± Zero adjusting for combustible and toxic indicators and 20.8% for Oxygen

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ADCO

MODEL MSA -361 LIMITATIONS 

 

   

Silicon based materials (e.g. silicates) in the tested atmosphere may seriously impair response of the instrument«. Why? Leaded gasoline vapours can also poison (desensitize) the catalytic filament of the instrument. Oxygen deficient (less than 10%) atmospheres may not indicate the true concentrations of combustible gas. Steamy sample will condensate inside the chamber (channel) and may cause inaccurate reading. Some gases act as interferents in H2S readings Cold to warm air = condensation problems Wet samples soaks the filter and fluctuates the readings. (liquid trap)

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ADCO

MODEL MSA -361 LIMITATIONS (Cont¶d) 

Combustible gas indicator detects only combustible gases and vapours in air. It will not indicate the presence of combustible airborne mists or dusts such as lubricating oils, coal dust and grain dust.



The Oxygen sensor detects the partial pressure of the Oxygen in the sample. What¶s that mean? Do not operate the instrument while the battery is being charged Note: You are NOT authorised to do any maintenance or calibration for the instrument. In case of any malfunction, replace the instrument and return it back to S & LP Section in order to be checked by ADCO approved technician. MSA361 - 50 ft extension tube will take 3 minutes for the final reading

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ADCO

Responsibility AGT 

Checking and monitoring gas testing devices for calibration due date.

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Making function and performance test at fresh air prior commencing actual gas test.

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In case of malfunction of the instrument (gas testing device), he shall refer to Area Safety & Loss Prevention Officer for replacement.Aware of the terminology, hazards and testing procedures associated with common gases / vapours in oil production / operations.

Safety & Loss Prevention Section 

Record keeping

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Maintaining database of AGT

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Advising AGT of requirements to re-validate the certificate.

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Arranging for calibration or maintenance at HSE Mussafah W/S.

Gas Testing Device Custodian 

Recharging of batteries.. 33

Gas Test

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