Gas Risk Management

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Gas Risk Management

• Sierra Monitor and Rep Firm Welcome
• ABC Engineering

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Gas Risk Management

• Introduction

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Gas Risk Management

• Was this caused by someone not paying attention?

4
Gas Risk Management

• Did some piece of equipment or instrumentation
  fail?

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Gas Risk Management

• Did someone not follow procedure?

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Gas Risk Management

• Could a properly functioning safety system
  have prevented the disaster?

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Gas Risk Management

• Explanation of hazardous gases
• Characteristics of common toxic gases
• Sensor Technology
• Portable and Fixed systems
• Placement of fixed sensors
• Elements of risk reduction
• Overview of available equipment
• Resources and reference
• Applications and usage

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Gas Risk Management

• Hazardous Gases

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Hazardous Gases

• Combustible Gases
• Explosion or fire hazard
• Must maintain concentration below lower explosive
  limit (LEL)
• Toxic Gases
• Hazardous to human health and safety
• Employee exposure must be limited
• Oxygen Displacing Gases
• Indirect human health hazard
• Deficiency of breathing Oxygen

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Combustible Gases

• Lower Explosive Limit (LEL)
• Also Lower Flammable Limit (LFL)
• What does it mean?
• Volume vs. LEL
• ASTM E681 Standard
• Benchmark test to determine LEL
• Tested in Air with 20.9 Oxygen

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Combustible Gases
100 LEL Methane 5 by volume
100
Too Rich for Combustion
Upper Explosive Limit U.E.L.
CONCENTRATION ( Gas in Air)
Will Support Combustion
Lower Explosive Limit 100 L.E.L.
Too Lean for Combustion
0
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Combustible Gases
Methane
Pentane

• The flammability of many gases lies in a very
  limited range
• The LEL differs depending upon the type of gas

100
100
CONCENTRATION ( Gas in Air)
CONCENTRATION ( Gas in Air)
15
UEL
7.8
UEL
5
100 LEL
1.5
100 LEL
0
0
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Combustible Gases

• Combustion Requires
• Fuel Source
• Oxygen or Air
• Ignition Source

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Combustible Gases

• Possible Ignition Sources
• Static Electricity Discharge
• Open Flames
• Hot Surfaces
• Mechanical Friction
• Electrical Arc or Spark
• Two Way Radio Transmitter
• Tools and Test Equipment

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Toxic Gases

• Hazard to Human Health and Life Safety
• PPM Parts Per Million
• 1 by volume 10,000 ppm
• 1 ppm .0001 by volume
• 1 millionth of the width of the U.S. is 12 feet

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Toxic Gases

• Permissible Exposure Limit (PEL)
• Time Weighted Average (TWA)
• Short Term Exposure Limit (STEL)
• Immediate Danger to Life and Health (IDLH)
• Relative Gas Density
• RGasD Air 1.0
• Lighter than air, Below 1.0
• Heavier than air, Above 1.0

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Carbon Monoxide Hazard

• Conc. of
• CO in Air Toxic Symptoms
• 100 ppm Fatigue and feeling of being tired
• 400 ppm Headache within 1-2 hrs., widespread in
  2.5 - 3.5 hrs.
• 500 ppm Dizziness, nausea, convulsions within 45
  min.
• 1,600 ppm Headache, dizziness, nausea within 20
  min. Death in 2 hours.
• 3,200 ppm Headache, nausea within 5-10 min.
  Death within 30 min.
• 6,400 ppm Headache, dizziness within 1-2 min.
  Death within 10-15 min.
• 12,800 ppm Death within 1-3 minutes.

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Carbon Monoxide Hazard

• OSHA General Industrial Safety Order for Carbon
  Monoxide
• Permissible Exposure Limit
• (Max. 8 hr. TWA) 50 ppm
• Short Term Excursion Limit (STEL) 200 ppm
  for 15 min/8 hrs
• IDLH 1200 ppm
• RGasD 0.97

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Chlorine Hazard

• Conc. of
• Cl2 in Air Toxic Symptoms
• 0.1 ppm Minimum concentration detectable by odor
• 3 ppm Difficulty breathing eye and throat
  irritation
• 10 ppm Causes serious throat irritation,
  smarting of eyes
• 30 ppm Coughing, more severe throat irritation,
  general feeling of discomfort in the chest
• 40 ppm Respiratory reflexes, coughing, burning
  of eyes, nausea, vomiting. Possible death
  within 30 minutes
• 100 ppm Death within a few breaths
• Uses Water purification, sanitation of
  industrial wastes, swimming pools, bleaching of
  pulp and textiles, manufacture of various
  chemical compounds

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Chlorine Hazard

• OSHA General Industrial Safety Order for Chlorine
• Permissible Exposure Limit
• (Max. 8 hr. TWA) 0.5 ppm
• Short Term Excursion Limit (STEL) 1 ppm for 15
  min/8 hrs
• IDLH 10 ppm
• RGasD 2.47

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Hydrogen Sulfide Hazard

• Conc. of
• H2S in Air Toxic Symptoms
• 1 ppm Odor detected, irritation of respiratory
  tract
• 10 ppm Allowable for 8 hours exposure (OSHA)
• 20 ppm Protective equipment is necessary
• 100 ppm Smell killed in 5 to 15 minutes. May
  burn
• eyes and throat coughing
• 500 ppm Respiratory disturbances in 2 to 15
  minutes. Coughing, collapse unconsciousness
• 1,000 ppm Immediate unconsciousness. Brain
  damage may result unless rescued promptly.
  Death in 3 to 5 minutes.

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Hydrogen Sulfide Hazard

• OSHA General Industrial Safety Order for Hydrogen
  Sulfide
• Permissible Exposure Limit
• (Max. 8 hr. TWA) 10 ppm
• Short Term Excursion Limit (STEL) 15 ppm for 10
  min/8 hrs
• IDLH 100 ppm
• RGasD 1.19

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Ammonia Hazard

• Conc. of
• NH3 in Air Toxic Symptoms
• 2 ppm First perceptible odor
• 40 ppm Slight eye and throat irritation
• 100 ppm Acute Irritation of eyes and nasal
  passages
• 400 ppm Severe irritation of throat, nose, upper
  respiratory tract
• 700 ppm Severe eye irritation
• 1700 ppm Serious coughing, bronchial spasms,
  death within 30 min.
• 5000 ppm Serious edema, strangulation, asphyxia,
  death immediate
• Uses Refrigerant gas, used in soil
  fertilization, ammoniate fertilizers. Used in
  metal treating and for extraction of metals from
  ores. Used as a neutralizing agent of acids in
  oil and in the manufacture of various chemical
  compounds. Also used to purify municipal water
  supplies.

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Ammonia Hazard

• OSHA General Industrial Safety Order for Ammonia
• Permissible Exposure Limit
• (Max. 8 hr. TWA) 25 ppm
• Short Term Excursion Limit (STEL) 35
  ppm for 15 min/8 hrs
• IDLH 300 ppm
• RGasD 0.60

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Oxygen Deficiency Hazard

• Oxygen
• Content Symptoms Developed
• 20.9 Normal Oxygen concentration in air
• 15 - 19 Decreased ability to work strenuously.
• May impair coordination
• 12 - 14 Respiration increases in exertion, pulse
  up, impaired coordination, perception
  judgment
• 8 - 10 Mental failure, fainting,
  unconsciousness, blueness of lips, nausea
  vomiting
• 6 - 8 8 minutes, 100 fatal 6 minutes, 50
  fatal,
• 4 - 5 minutes, recovery with treatment
• 4 - 6 Coma in 40 seconds, convulsions,
  respiration ceases, death

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Oxygen Deficiency Hazard

• Industry Guidelines for Oxygen Deficiency
• Breathing gear required below 19.5 and above
  23.5 Oxygen content in air
• Confined Space permit procedures may need be
  followed in some areas

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Gas Risk Management

• Gas Sensor Technology

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Sensor Technology

• Catalytic Bead
• Infrared
• Electrochemical
• Semiconductor

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Catalytic Bead

• No Temperature or Humidity Effect
• Silicone and Sulfide Resistant
• 0-100 L.E.L. Scale
• Responds to All Combustible Gases
• Wheatstone Bridge

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Catalytic Bead
Wheatstone Bridge
Compensator
DC Supply
Detector
Output
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Infrared

• Methane or Propane
• Carbon Dioxide
• Accurate Stable
• Large Measurement Range
• Low Maintenance

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Electrochemical

• Current Generating Electrolytic Reaction
• High sensitivity for PPM levels of Toxic Gas
• Specificity to Gas of Interest
• Percent Volume for Oxygen Measurement

Diffusion Point
Electrolyte
Electrodes
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Semiconductor (Solid State)

• Long Life Sensor
• Semiconductor Resistive Film
• PPM Range
• High Sensitivity
• Poor Selectivity
• Non-Linear Response

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Detection Techniques

• Combustible Catalytic bead, Semiconductor,
  Infrared
• Oxygen Electrochemical
• Toxic Gases Semiconductor, Electrochemical,
  Infrared

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Gas Risk Management

• Explanation of hazardous gases
• Characteristics of common toxic gases
• Sensor Technology
• Portable and Fixed systems
• Placement of fixed sensors
• Elements of risk reduction
• Overview of available equipment
• Resources and reference
• Applications and usage

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Portables vs. Fixed

• Use Portables
• When area is not normally occupied
• When area has no power or infrastructure
• When temporary work crew must maintain their own
  safety equipment
• When fixed system is down for maintenance
• Use of Fixed Systems
• When area is regularly occupied
• When automatic systems must react to a hazardous
  gas condition
• When insurance or regulatory issues require it
• When risk assessment concludes that area must be
  monitored continuously 24/7

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Portable Devices

• Battery Powered
• Can be moved from area to area
• Monitor is attached to the individual who is
  performing the work
• Prone to damage
• Should be calibrated before every use

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Permanent Fixed Installations
SCADA
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Calibration Validation

• Factory Mutual (FM) requires that all approved
  sensors be calibrated periodically
• Sensor must be exposed to live gas standard to
  validate performance
• Regular calibration compensates for environmental
  changes
• Records must be maintained to meet OSHA Due
  Diligence requirements
• Calibration gas must be certified as primary gas
  standard

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Gas Risk Management

• Gas Sensor Placement

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Gas Sensor Placement

• Use engineering judgement
• Consider
• Probability of gas leak
• Quantity of gas that could leak
• Environmental conditions
• Dilution rates and convection currents
• Density of gas
• Interfering gases

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Gas Sensor Placement

• Place sensors close to possible gas source
• Place sensors in areas where gas might accumulate
• Place toxic gas and oxygen deficiency sensors in
  the breathing zone
• Consider accessibility and maintenance issues

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Gas Weight in Relation to Air

• Ammonia Lighter
• Butane Heavier
• Carbon Dioxide Heavier
• Carbon Monoxide Slightly Lighter
• Methane Lighter
• Chlorine Heavier
• Ethane Slightly Heavier
• Ethylene Slightly Lighter
• Heptane Heavier
• Hydrogen Lighter

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Gas Weight in Relation to Air

• Hydrogen Chloride Heavier
• Hydrogen Cyanide Lighter
• Hydrogen Sulfide Heavier
• Methyl Alcohol Heavier
• Nitric Oxide Slightly Heavier
• Nitrogen Dioxide Heavier
• Pentane Heavier
• Propane Heavier
• Sulfur Dioxide Heavier
• Toluene Heavier

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Gas Risk Management

• Risk Reduction

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Responsible Risk Management

• Identify hazards...
• Assess risk of hazardous event...
• Comply with laws, insurance requirements...
• Consider liability, financial risks...
• Develop and implement a strategy of comprehensive
  event response and prudent risk management

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Risk Reduction
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Proper Equipment Selection

• Portable systems
• Minimal risk of hazardous event
• Battery powered, must be carried on person
• Gas Alarm Monitors
• Minimal risk of hazardous event
• Simple alarm alert, relay output
• Analog Monitors
• Moderate risk in defined location
• Continuous display, warning and high alarms,
  limited diagnostics

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Proper Equipment Selection

• Gas Alarm Monitors/Systems
• Analog Monitors (Single Point)
• Distributed Digital Systems (Multi-Point)

Multi-Point Systems
Gas Alarm Systems
Single Point Systems
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Proper Equipment Selection

• Risk Management Systems
• Constant risk of hazardous event, defined areas
  or facility-wide
• Distributed intelligence for local control and
  remote monitoring
• Comprehensive event response
• Configurable alarm logic
• Extensive calibration, diagnostic capabilities
• Documentation of due diligence

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Sentry - Basic Configuration
110 VAC or 220 VAC
12 - 28 VDC
Low Alarm
High Alarm
Trouble
RS232 Serial Output to Printer
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Resources Reference

• ANSI/NFPA 325 Guide to fire hazard properties of
  flammable liquids, gases and volatile solids
• ANSI/NFPA 820 Fire protection in wastewater
  treatment and collection facilities
• NIOSH Guide to chemical hazards
• OSHA Guide for confined space hazards

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Markets - Gas Detection

• Water/Wastewater Treatment Plants
• Chemical/Petrochemical Plants
• Landfills Solid Waste
• Alternate Fueled Vehicles
• Food Drug
• Parking Garages
• Gas/Oil Operations
• Pulp Paper

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Water/Wastewater Treatment

• Pumping Stations
• Combustible gases, H2S, O2
• Influent/Barscreen Rooms
• Combustible gas, O2
• Grit Chamber Wet Wells
• Combustibles, O2, H2S
• Digester
• Combustible gas, H2S
• Furnace Room
• Combustible gas, CO
• Disinfection/ Dechlorination
• Cl2, SO2, NH3

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Chemical/Petrochemical Plants

• Pipelines compressor stations
• Combustible gas, H2S, flame
• Laboratories
• Toxic gases, O2 deficiency
• Railroad/truck loading stations
• Combustibles, toxics, flame
• Storage tanks
• Combustibles, flame

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Gas/Oil Operations

• Well site perimeters
• Combustible gas, H2S
• Sweetening plants, sour gas wells H2S
• Pipelines compressor stations
• Combustibles, toxics, flame
• Drilling operations
• Combustible gas, H2S, oxygen deficiency, flame
• Combustible gas leaks

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Remote Site Monitoring

• Modbus RTU serial communication link from Sentry
  interfaces to a FieldServer WebServer
• WebServer uses Sentry data to build dynamic
  browser pages
• Browser pages may be viewed over LAN, WAN or
  Internet

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Sentry WebServer

• The Main screen ranges from the default layout of
  a single Sentry system to custom graphics that
  can include a photo or drawing of the building
  with buttons to specific zones

Default
Custom
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Review Discussion

• Sierra Monitor Corporation
• www.sierramonitor.com
• 800-72-SIERRA
• 800-727-4377
• FieldServer Technologies
• www.fieldserver.com
• 888 509-1970