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Blender Lesson Guide
Blender Lesson Guide
Blender Lesson Guide
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Blender Lesson Guide

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RELATED TO DIVING GASES

RELATED TO DIVING GASES

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Transcript

  • 1. Gas Blender Course Diving Science And Technology
  • 2. Course Outline
    • Oxygen
    • Oxygen Cleaning
    • Oxygen Compatible Air
    • Gas Blending Methods
    • Blending Helium Mixes
    • Appendices
    Introduction -1
  • 3. Overall Program Goal
    • To direct you in the accepted safety protocols and standards of blending breathing gases for diving
    Introduction -2
  • 4. Why?
    • The benefits or necessity of diving with breathing gases other than air has resulted in a demand for these gas mixes
      • Comparatively few individuals or facilities are trained to fill this need
      • The world needs trained gas blenders!
    Introduction -3
  • 5. Chapter One Oxygen
  • 6. Chapter One
    • Overview
      • Oxygen: What is it?
      • The “Forty Percent Rule”
      • Operational Hazards
      • Fires and Deflagrations
      • Oxygen Service
    Chapter 1-1
  • 7. Oxygen: what is it?
    • Blender Objectives:
      • What are the physical properties of oxygen?
      • What are the four main types of oxygen?
      • What are the two main sources of oxygen?
      • What are the two types of high pressure breathing grade oxygen?
      • What is liquid oxygen?
    Chapter 1-2
  • 8. Oxygen: what is it?
    • What are the physical properties of oxygen ?
      • Oxygen is a colorless, odorless gas that supports life and makes combustion possible
      • Oxygen is responsible for oxidation i.e. rust, fire, etc.
      • Oxygen itself doesn’t burn
      • U.S. Compressed Gas Association standards for all oxygen is 99.5 percent pure
    Chapter 1-3
  • 9. Oxygen: what is it?
    • What are the four main types of oxygen?
      • Welding grade
      • United States Pharmacopoeia (USP – also called medical grade)
      • Aviator grade
      • Liquid oxygen (LOX)
    Chapter 1-4
  • 10. Oxygen: what is it?
    • Can all four types of oxygen be used for breathing mixes?
      • No
        • Welding oxygen should not be used for blending enriched air nitrox
    Chapter 1-5
  • 11. Oxygen: what is it?
    • Why shouldn’t welding oxygen be used in blending breathing gas mixes?
      • Breathing grade oxygen cylinders are drawn into a vacuum before refilling, welding cylinders are not
        • This could result in contamination in the welding cylinder
    Chapter 1-6
  • 12. Oxygen: what is it?
    • What are the two main sources of oxygen?
      • Supplied from an industrial or medical gas source
      • Manufactured on site by pressure swing absorption or the membrane system
    Chapter 1-7
  • 13. Oxygen: what is it?
    • What are the two types of high pressure breathing grade oxygen?
      • United States Pharmacopoeia (USP grade) also known as medical grade oxygen
      • Aviator grade
    Chapter 1-8
  • 14. Oxygen: what is it?
    • What is the difference between USP and Aviator grade oxygen?
      • Aviator grade oxygen is identical to USP grade except that it is drier
    Chapter 1-9
  • 15. Oxygen: what is it?
    • What is Liquid Oxygen (LOX) ?
      • Liquid oxygen is oxygen chilled into a liquid state
      • Low pressure (up to 20 bar/300 psi.)
      • Concentrated volume
      • Evaporation rate is 1.5% per day
    Chapter 1-10
  • 16. The 40% Rule
    • Blender Objectives:
      • What is the “40 percent rule”?
      • How does the “40 percent rule” affect the gas blender?
      • What are the considerations for handling oxygen concentrations above 40 percent?
    Chapter 1-11
  • 17.
    • What is the “40 percent rule”?
      • More of a guideline than a “rule”, the forty percent question is:
        • At what oxygen concentration does a gas become dangerous to handle?
          • Historically, the dive industry treats up to 40% oxygen the same as air
          • Any concentration of O2 above 40% is handled as if it is pure oxygen
    The 40% Rule Chapter 1-12
  • 18.
    • How does the “40 percent rule” affect the gas blender?
      • The 40 percent rule is just part of the oxygen safety equation
      • Pressures, operating temperatures, equipment design, flow rate, contamination, oxygen compatible components, and operating procedures all play an important role in blender safety
    The 40% Rule Chapter 1-13
  • 19.
    • What are the considerations for handling oxygen concentrations above 40 percent?
      • By removing one of the necessary ingredients for fire, a blender can safely work with concentrations of oxygen above 40%
        • This requires not providing a likely ignition source or fuel source
    The 40% Rule Chapter 1-14
  • 20. Operational Hazards
    • Blender Objectives:
      • What is a deflagration?
      • What is ignition?
      • How does oxygen affect combustion?
      • What three things are required for a fire to exist?
      • What are the four main sources of ignition?
    Chapter 1-15
  • 21. Operational Hazards
    • What is a deflagration?
      • A ferocious fire with enough heat to potentially melt an opening in the pressure containment system, resulting in the sudden release of pressure
    Chapter 1-16
  • 22. Operational Hazards
    • What is ignition?
      • A chemical reaction that releases energy as heat that in turn is sufficient to sustain the reaction
    Chapter 1-17
  • 23. Operational Hazards
    • What are oxygen ignition sources?
      • Ignition sources
        • Heat of Compression
        • Particle Impingement
        • Frictional Heating
        • Sparks/Arcs/Static
    Chapter 1-18
  • 24. Operational Hazards
    • How does oxygen affect combustion?
      • Oxygen enhances combustion, increasing the intensity of the fire
        • The more oxygen, the greater the intensity
    Chapter 1-19
  • 25. Operational Hazards
    • What three things are required for a fire to exist?
      • Fire requires
        • Fuel
        • An ignition source
        • An oxidizer
    Chapter 1-20
  • 26. Operational Hazards
    • What are the four main sources of ignition?
      • Heat of Compression
      • Particle Impingement
      • Frictional Heating
      • Arcs/Sparks/Static
    Chapter 1-21
  • 27. Operational Hazards
    • What is “heat of compression”?
      • Heat of compression is the heat generated when a gas is compressed from a low to a high pressure
    Chapter 1-22
  • 28. Operational Hazards
    • How do you prevent “heat of compression”?
      • If possible use regulators instead of valves
      • Give the pressure somewhere to go
        • Open a downstream valve slightly or crack a fill whip partially open
      • Open valves slowly
    Chapter 1-23
  • 29. Operational Hazards
    • Where should you place gauges in a high-pressure oxygen system?
      • Do not place gauges in areas that are subject to uncontrolled compression
      • Place gauges in protected locations such as
        • Downstream of regulators
        • Slow opening valves
    Chapter 1-24
  • 30. Operational Hazards
    • What is “particle impingement”?
      • Particle impingement is when heat is generated as particles strike material with sufficient velocity to ignite the particle and/or the material
      • Materials such as aluminum and titanium are susceptible
    Chapter 1-25
  • 31. Operational Hazards
    • How do you prevent particle impingement?
      • Particle impingement may occur if an impact point is closer than ten times the diameter downstream of a flow restrictor or pressure drop
      • The velocity required is at least 46m/150ft per second
    Chapter 1-26
  • 32. Operational Hazards
    • What are the design considerations to eliminate particle impingement as an ignition source?
      • Use monel or brass not aluminum or titanium
      • Use filters to limit particles upstream of high velocity components
    Chapter 1-27
  • 33. Operational Hazards
    • What are the design considerations to eliminate particle impingement as an ignition source?
      • Don’t allow particle generation when assembling components
      • Purge systems with a high velocity inert gas after assembly, but before use
    Chapter 1-28
  • 34. Operational Hazards
    • What is frictional heating?
      • Frictional heating is concentrated, localized heating caused by flow friction
      • It is the result of gases speeding up over a polymer as it goes past a restriction
      • This can occur in a worn valve where O2 or EANx escapes past the nylon seat
    Chapter 1-29
  • 35. Operational Hazards
    • How do you prevent frictional heating?
      • Visually inspect all valve and regulator seats
      • Listen for gas escaping a closed valve
      • Do not crank down valves to close
      • Be aware of cylinders or systems losing pressure over time
      • Test for leaks especially at the tank/valve interface
    Chapter 1-30
  • 36. Operational Hazards
    • What causes arcs, sparks, and static?
      • These electrical discharges are caused by:
        • Powered systems motors
        • Switches
        • Static discharge
    Chapter 1-31
  • 37. Operational Hazards
    • How do you eliminate arcs, sparks, and static?
      • Ensure the proper functioning of all electrical systems including the proper grounding of all equipment
    Chapter 1-32
  • 38. Operational Hazards
    • What are three other ignition sources?
      • Mechanical impact
        • Example would be the chatter that sometimes occurs in some remote valves on actuation
      • Thermal runaway
        • The combustion of the compressors’ oil if the temp exceeds the flash point
      • Chemical reaction
        • Ignition in the filtration towers
    Chapter 1-33
  • 39. Operational Hazards
    • How do you prevent these ignition sources?
      • Develop an understanding of what is required to create and sustain a fire in a pressure system, then insure that it doesn’t happen
        • It is a combination of oxygen concentration, pressure, temperature, contamination, ignition sources, gas velocity, material compatibility and system design that is required for a fire
    Chapter 1-34
  • 40. Oxygen Service
    • Blender objectives:
      • What three conditions are required for oxygen service?
      • What is meant by “designed for oxygen use”?
      • What is meant by “oxygen compatible”?
    Chapter 1-35
  • 41. Oxygen Service
    • What three conditions are required for oxygen service?
      • Designed for oxygen use
      • Oxygen clean
      • Oxygen compatible
    Chapter 1-36
  • 42. Oxygen Service
    • What is meant by ”designed for oxygen use”?
      • Consideration must be given for the special needs required for oxygen at the systems maximum pressure and temperature
      • The design must minimize any tendency for heat generation, ignition of particles, or the accumulation of contamination
    Chapter 1-36
  • 43. Oxygen Service
    • Why is design for oxygen use important?
      • System design is the cornerstone of a safe oxygen enriched system
      • Without proper design considerations, a system would be either unsafe to use from the onset or would eventually become unsafe due to contamination build up or material compatibility degradation
    Chapter 1-37
  • 44. Oxygen Service
    • What eight items must be considered for oxygen use design?
      • Regulators instead of valves
      • Slow opening valves
      • Oxygen compatible parts
      • Ease of oxygen cleaning and testing
    Chapter 1-38
  • 45. Oxygen Service
      • Short sections of pipe on ends of teflon lined stainless steel braided hoses
      • Filters in place ahead of high velocity components
      • Gauges installed in protected places
      • Oxygen compatible air
    Chapter 1-39
  • 46. Oxygen Service
    • What is oxygen clean?
      • Oxygen clean is the verifiable absence of particulate, fiber, oil, grease and other contaminants
    Chapter 1-40
  • 47. Oxygen Service
    • What is “verifiable absence”?
      • Verifiable absence is determined through the use of qualitative and quantitative cleanliness measurement techniques
    Chapter 1-41
  • 48. Oxygen Service
    • What is meant by “oxygen compatible”?
      • Material compatibility is where a material can co-exist with elevated oxygen concentrations and a potential source of ignition, without flashing, based on the systems’ maximum operating pressure and temperature
    Chapter 1-42
  • 49. Oxygen Service
    • Why is oxygen compatible a concern in oxygen systems?
      • Every application differs due to pressures, system design, maximum operating temperature, oxygen concentration, etc.
      • These variables, combined with the inherent ambiguity of material compatibility, make it important to consult with industry experts for your application
    Chapter 1-43
  • 50. Oxygen Service
    • Where is material compatibility a factor?
      • In all systems that will be exposed to above a forty percent oxygen concentration and 150 psi
      • Any equipment manufacturer will inform you as to the applicability of their product for use in an oxygen enriched environment
      • Some will require the substitution of oxygen compatible parts
    Chapter 1-44
  • 51. Chapter One
    • Review
      • Oxygen: what is it?
      • The “Forty Percent Rule”
      • Operational Hazards
      • Fires and Deflagrations
      • Oxygen Service
    Chapter 1-45
  • 52. Chapter One
    • Questions?
    Chapter 1-46
  • 53. Chapter Two Oxygen Cleaning
  • 54. Chapter Two
    • Overview
      • Oxygen clean standard
      • Importance of oxygen clean standard
      • Six steps for oxygen cleaning
      • Quantifying cleaning results
      • Six tests for oxygen cleaning
    Chapter 2-1
  • 55. Oxygen Cleaning
    • Blender Objectives:
      • What is the oxygen clean standard?
      • Why is the oxygen clean standard required?
      • Why is it important to quantify cleaning results by testing?
      • What are the six tests for oxygen cleaning?
    Chapter 2-2
  • 56. Oxygen Clean Standard
    • What is the oxygen clean standard?
      • The oxygen clean standard is the verifiable absence of particulate, fiber, oil, grease and other contaminants
      • Verifiable absence is determined through the use of qualitative and quantitative cleanliness measurement techniques
    Chapter 2-3
  • 57. Importance of Oxygen Clean Standard
    • Why is the oxygen clean standard required?
      • The oxygen clean standard is required to ensure that there is no contamination that could become an ignition source or a fuel source for a fire or deflagration within an oxygen enriched environment under the systems normal operating pressures, temperatures and gas velocities
    Chapter 2-4
  • 58. Six Steps for Oxygen Cleaning
    • What are the six steps for oxygen cleaning?
      • Completely dismantle all equipment parts
      • Inspect and gross clean all parts
      • Preclean and rinse
      • Final clean, rinse, and dry
      • Inspecting and testing for clean
      • Reassembling, packaging and labeling
    Chapter 2-5
  • 59. Six Steps for Oxygen Cleaning
    • Step 1: Completely dismantle all equipment parts
      • Dismantle equipment to simplest components
      • Use the correct tools to ensure no damage to the parts
      • Be organized with specific containers for small parts
    Chapter 2-6
  • 60. Six Steps for Oxygen Cleaning
    • Step 2: Inspect and gross clean all parts
      • Inspect each part for oxygen compatibility, corrosion, wear, and contamination
        • Use a non metallic brush and a mildly acidic solution to clean each part
      • The use of an ultrasonic cleaner is recommended
        • After rinsing, inspect parts for coarse particle contamination, i.e. rust, scale, etc.
    Chapter 2-7
  • 61. Six Steps for Oxygen Cleaning
    • Step 3: Pre clean and rinse
      • Pre-cleaning removes all visible contamination by using cleaning solutions that clean and rinse off well
        • Scrub with anon metallic brush
      • The use of an ultra-sonic cleaner is recommended
        • After rinsing, visually inspect parts for any contamination, re clean if necessary
    Chapter 2-8
  • 62. Six Steps for Oxygen Cleaning
    • Step 4: Final clean, rinse, and dry
      • The final cleaning is to remove any organic residual remaining from the previous cleaning solution
        • Caustic (alkaline) cleaners are used for this purpose
      • Thoroughly rinse caustic cleaners from the parts
      • Dry with oxygen compatible air or anhydrous nitrogen
    Chapter 2-9
  • 63. Six Steps for Oxygen Cleaning
    • Step 5: Inspecting and testing for clean
      • Once oxygen cleaned, every part must be tested before being assembled or packaged for storage
      • If a part fails any of the six tests, the part must be cleaned and tested again
    Chapter 2-10
  • 64. Six Steps for Oxygen Cleaning
    • Step 6: Reassembling, packaging and labeling
      • Once oxygen cleaned and tested, the system/equipment needs to be reassembled
        • Use oxygen compatible parts and lubricants
        • Do not wrap Teflon tape past the last two threads
    Chapter 2-11
  • 65. Oxygen Cleaning
    • Step 6 continued: Reassembling, packaging and labeling
      • Do not contaminate parts by careless handling
        • If parts are not going back into service then seal in clean plastic bags, label with the date
        • Enter parts into the oxygen service log
    Chapter 2-12
  • 66. Quantifying Cleaning Results
    • Why is it important to quantify cleaning results by testing?
      • To ensure that the system is clean enough to be used in an oxygen enriched environment with the systems working pressure, temperature and gas velocities
      • Any contamination could become an ignition source or fuel for a fire or deflagration
    Chapter 2-13
  • 67. Six Tests for Oxygen Clean
    • What are six tests for oxygen clean?
      • PH test
      • White light visual inspection
      • Ultraviolet light visual inspection
      • Water break test
      • Shake test
      • Swipe test
    Chapter 2-14
  • 68. Six Tests for Oxygen Clean
    • Test 1: PH Test
      • The PH test is used to determine whether or not the caustic (alkaline) cleaning solutions have been completely rinsed out/removed
      • Test an unused fresh sample of rinse water with a PH test strip
        • This is your control sample
    Chapter 2-15
  • 69. Six Tests for Oxygen Clean
    • Test 1: PH Test continued
      • Test a used sample of rinse water and compare results
        • If it tests higher, then rinse again
        • A reading of eight or less will indicate that the caustic has been rinsed out
    Chapter 2-16
  • 70. Six Tests for Oxygen Clean
    • Test 2: White Light Visual Inspection
      • Is a definitive visual inspection using a minimum 60 watt white light to closely inspect every part
        • This inspection will reveal contamination 50 microns in size and larger
    Chapter 2-17
  • 71. Six Tests for Oxygen Clean
    • Test 3: Ultraviolet Light Visual Inspection
      • Some contaminants fluoresce under ultraviolet light
      • Visual inspection using an ultra violet light in the 3600 to 3900 angstrom range will show if contamination is present
        • Note that most synthetic oil residues will not fluoresce but ink, grease, dye, oil, fibers, and most particulate will.
    Chapter 2-18
  • 72. Six Tests for Oxygen Clean
    • Test 4: Water Break Test
      • Is used to indicate residual silicon, oils, or grease
      • Mist the surface of the oxygen cleaned part to provide a continuous thin layer of water
      • Gravity acting on the layer of water will cause it to break free from the part
      • Any residual droplets adhering to the part indicates contamination
    Chapter 2-19
  • 73. Six Tests for Oxygen Clean
    • Test 5: Shake Test
      • Is used to confirm that all of the cleaning solutions have been removed, thoroughly rinsed from the part
      • Half fill a oxygen cleaned container (about 2 cups) with the final rinse water
      • Shake vigorously for five seconds, then let stand for five minutes
      • Any bubbles remaining indicates contamination
    Chapter 2-20
  • 74. Six Tests for Oxygen Clean
    • Test 6: Swipe Test
      • Is used to test for remaining adhering contaminants
      • It is especially good for testing the neck threads of cylinders
      • Swipe the test area once, in one direction, with a clean, lint free, white cloth or lens tissue
      • Examine the cloth under a white and an ultra violet light looking for contaminants
    Chapter 2-21
  • 75. Chapter Two
    • Review
      • Oxygen clean standard
      • Importance of oxygen clean standard
      • Six steps for oxygen cleaning
      • Quantifying cleaning results
      • Six tests for oxygen cleaning
    Chapter 2-22
  • 76. Chapter Two
    • Questions?
    Chapter 2-23
  • 77. Chapter Three Oxygen Compatible Air
  • 78. Chapter Three
    • Overview
      • Oxygen compatible air
      • Entrained oil
      • Carbonization
    Chapter 3-1
  • 79. Oxygen Compatible Air
    • Blender Objectives:
      • What is oxygen compatible air?
      • What is the difference between CGA Grade E and modified Grade E air?
      • Why is oxygen compatible air required?
      • When is oxygen compatible air required?
    Chapter 3-2
  • 80. Oxygen Compatible Air
    • What is oxygen compatible air?
      • Oxygen compatible air is breathing grade air with a higher standard for the presence of condensed hydrocarbons and carbon monoxide
        • The rationale is that with sustained compressor operations there could be a unacceptable build up of condensed hydrocarbons with grade E air
        • This hydrocarbon build up could be a fuel source in an oxygen enriched environment
    Chapter 3-3
  • 81. Oxygen Compatible Air
    • What is the difference between CGA Grade E and modified Grade E air?
      • Modified Grade E air has a more restrictive .1 mg/m3 for condensed hydrocarbons compared to Grade E at 5. mg/m3 in the U.S. and 1. mg/m3 in Canada
    Chapter 3-4
  • 82. Oxygen Compatible Air
    • What is the difference between CGA Grade E and modified Grade E air?
      • Carbon monoxide is limited to 2 parts per million in modified Grade E down from 10 parts per million allowed in Grade E
    Chapter 3-5
  • 83. Oxygen Compatible Air
    • Why is oxygen compatible air required?
      • A build up of condensed hydrocarbons in a pressure system could provide a fuel source in an oxygen enriched environment (above 40 percent oxygen) at the systems working pressure, temperature and gas velocity when exposed to an ignition source
    Chapter 3-6
  • 84. Oxygen Compatible Air
    • When is oxygen compatible air required?
      • Any time the concentration of oxygen in a gas mix exceeds 40 percent, every part of the containment system must be oxygen serviced
        • To maintain an oxygen serviced state only oxygen compatible air (modified Grade E) can be used
      • If the system is never exposed to above 40 percent oxygen it does not require oxygen service nor oxygen compatible air
    Chapter 3-7
  • 85. Entrained Oil
    • Blender Objectives:
      • What is entrained oil?
      • What causes entrained oil?
      • Why is entrained oil potentially hazardous?
      • Why is synthetic oil often used for high pressure oxygen enriched systems?
    Chapter 3-8
  • 86. Entrained Oil
    • What is entrained oil?
      • Entrained oil is the lubrication oil in a compressor that gets into the discharge air
    Chapter 3-9
  • 87. Entrained Oil
    • What causes entrained oil?
      • Compressor design
      • Worn internal parts
      • Poor operating conditions
      • Poor maintenance
      • Insufficient inter-stage drainage
      • Lack of coalescer drainage
      • Inadequate filter maintenance
      • Elevated temperatures
    Chapter 3-10
  • 88. Entrained Oil
    • Why is entrained oil potentially hazardous?
      • Because entrained oil is a condensed hydrocarbon
        • Even small amounts are potentially dangerous when exposed to higher oxygen concentrations under pressure
      • The accumulated hydrocarbons become a ready fuel source just waiting for an ignition source
    Chapter 3-11
  • 89. Entrained Oil
    • Why is synthetic oil often used for high pressure oxygen enriched systems?
      • Synthetic compressor oil is considered less harmful to a diver if breathed
      • There are fewer hydrocarbons in synthetic oil making it less of a combustion risk
      • Synthetic oils have a higher flash point requiring a higher temperature for ignition
    Chapter 3-12
  • 90. Carbonization
    • Blender Objectives:
      • What is carbonization, and what results from it?
      • What are the possible causes of carbonization?
      • What do elevated carbon monoxide and/or carbon dioxide levels indicate?
    Chapter 3-13
  • 91. Carbonization
    • What is carbonization, and what results from it?
      • Carbonization is the result of over heated compressor oil beginning to combust inside the compressor
      • Carbon dioxide is the result of incomplete combustion
    Chapter 3-14
  • 92. Carbonization
    • What are the possible causes of carbonization?
      • Restriction of the first stage intake
      • Inter-stage leakage
      • Low oil level
      • Contaminated oil
      • The wrong type of oil
    Chapter 3-15
  • 93. Carbonization
    • What are the possible causes of carbonization?
      • A dirty compressor
      • Lack of proper air circulation
      • Lack of coolant circulation
    Chapter 3-16
  • 94. Carbonization
    • What do elevated carbon monoxide and/or carbon dioxide levels indicate?
      • The presence of either of these gases indicate a seriously overheated compressor
        • The carbon dioxide is caused by carbon monoxide being chemically altered by the hopcalite portion of the chemical filter
    Chapter 3-17
  • 95. Carbonization
    • What do elevated carbon monoxide and/or carbon dioxide levels indicate?
      • In turn the carbon dioxide is largely absorbed by the activated carbon
      • Moisture in the filter will diminish the hopcalite and activated carbons capacities
    Chapter 3-18
  • 96. Chapter Three
    • Review
      • Oxygen compatible air
      • Entrained oil
      • Carbonization
    Chapter 3-19
  • 97. Chapter Three
    • Questions?
    Chapter 3-20
  • 98. Chapter Four Gas Blending Methods
  • 99. Chapter Four
    • Overview
      • Blending enriched air nitrox
      • Advantages & disadvantages of blending
    Chapter 4-1
  • 100. Gas Blending Methods
    • Blender Objectives:
      • What are the five methods of blending enriched air nitrox?
      • What are the advantages and disadvantages of each?
      • What are the principles involved in using gas generation systems, mixing by weight, and premixed supplied?
      • Why is oxygen servicing important when partial pressure blending?
    Chapter 4-2
  • 101. Gas Blending Methods
    • What are the five methods of blending enriched air nitrox?
      • Mixing by weight
      • Partial pressure blending
      • Continuous flow mixing
      • Oxygen generation
      • Premix supplied
    Chapter 4-3
  • 102. Gas Blending Methods
    • Method 1: Mixing by weight
      • Based on the weight of each gas, the correct volumes are flowed into a collection container
      • Due to the lack of turbulence, a minimum of six hours is required for molecular migration to provide a homogeneous mix
    Chapter 4-4
  • 103. Gas Blending Methods
    • Method 1: Mixing by weight continued
      • Gas analysis will indicate the requirement for gas additions to achieve the desired EANx mix
    Chapter 4-5
  • 104. Gas Blending Methods
    • Method 2: Partial pressure blending
      • Partial pressure blending is simply flowing pure oxygen into a cylinder and topping up with oxygen compatible air to the cylinders working pressure
      • Air is used because it is primarily 79% nitrogen and 21% oxygen
        • The oxygen content of air is basically a bonus
    Chapter 4-6
  • 105. Gas Blending Methods Chapter 4-7
  • 106. Gas Blending Methods Chapter 4-8
  • 107. Gas Blending Methods
    • Method 3: Continuous flow mixing
      • Continuous blending actually mixes low pressure oxygen and air before being compressed to a working pressure
    Chapter 4-9
  • 108. Gas Blending Methods Chapter 4-10
  • 109. Gas Blending Methods Chapter 4-11
  • 110. Gas Blending Methods
    • Method 4: Oxygen generation
      • There are two types
        • The pressure swing absorption system
        • Differential permeability (the membrane system)
    Chapter 4-12
  • 111. Gas Blending Methods Chapter 4-13
  • 112. Gas Blending Methods Chapter 4-14
  • 113. Gas Blending Methods Chapter 4-15
  • 114. Gas Blending Methods
    • Method 5: Premix supplied
      • Industrial suppliers of gas can provide any oxygen enriched air mix required….for a price
    Chapter 4-16
  • 115. Advantages & Disadvantages
    • What are the advantages and disadvantages of each?
      • Method 1: Mixing by weight
        • Is only used by large diving operations that require one mix
        • Accurate weights/volumes must be established and temperature is critical
        • This is not a practical solution for rec/tec diving operations
    Chapter 4-17
  • 116. Advantages & Disadvantages
      • Method 2: Partial Pressure Blending
        • Everything with this system must be oxygen serviced and remain that way
        • Oxygen service is not as much of a problem with large systems where the gas is mixed into cascade cylinders as the blender has control over the introduction of contaminates
    Chapter 4-18
  • 117. Advantages & Disadvantages
      • Method 2: Partial Pressure Blending continued
        • For this reason, partial pressure blending should not be done in scuba cylinders
        • Gas temperatures are critical for accurate mixes
        • This system is relatively slow as oxygen should not be flowed at more than 70 psi per minute
    Chapter 4-19
  • 118. Advantages & Disadvantages
      • Method 2: Partial Pressure Blending continued
        • For decompression mixes above 40% this is the only viable method of mixing
        • Unless an oxygen serviced booster is available, all of the oxygen supply cannot be used due to the higher pressure requirements for mixing
    Chapter 4-20
  • 119. Advantages & Disadvantages
      • Method 3: Continuous Mixing
        • Inherently accurate mixes
        • Except the oxygen regulator, there is no oxygen service requirements as the oxygen is low pressure and limited to 40%
    Chapter 4-21
  • 120. Advantages & Disadvantages
      • Method 3: Continuous Mixing continued
        • Disadvantage is that in a oil lubricated compressor, the mix is limited to 40 %
        • Simple to setup, use and understand
        • There is no wasted oxygen as all of the gas in the oxygen cylinder can be used
    Chapter 4-22
  • 121. Advantages & Disadvantages
      • Method 4: Oxygen Generation Systems
        • The pressure swing absorption (PSA) system makes up to 95 % oxygen at 205 bar/3000 psi
          • It does not make EANx
        • The Differential permeability system makes up to 40% EANx and does not require oxygen service
    Chapter 4-23
  • 122. Advantages & Disadvantages
      • Method 4: Oxygen Generation Systems continued
        • Both systems are more expensive than the others but they don’t require an oxygen supply
    Chapter 4-24
  • 123. Advantages & Disadvantages
      • Method 5: Premix
        • No equipment requirements
        • Does not require oxygen service if delivered below 40%
        • Requires a booster or cascade to optimize gas pressure
        • Can get expensive
    Chapter 4-25
  • 124. Chapter Four
    • Review
      • Blending enriched air nitrox
      • Advantages & disadvantages of blending
    Chapter 4-26
  • 125. Chapter Four
    • Questions?
    Chapter 4-27
  • 126. Chapter Five Blending Helium Mixes
  • 127. Chapter 5
    • Overview
      • Using helium
      • Types of helium mixes
      • Partial pressure blending methods
      • Continuous blending
      • Oxygen levels
      • Blending helium-based mixes
    Chapter 5-1
  • 128. Blending Helium Mixes
    • Blender Objectives:
      • Why do we dive using helium?
      • What are the different types of helium mixes?
      • Describe the different types of helium blends.
    Chapter 5-2
  • 129. Blending Helium Mixes
    • Blender Objectives
      • List the steps required for mixing trimix, heliair and helitrox using continuous blending.
      • What are the minimum oxygen levels required to sustain consciousness?
      • What are some of the issues unique to blending helium-based mixes?
    Chapter 5-3
  • 130. Using Helium
    • Why do we dive using helium mixes?
      • To reduce narcosis to a tolerable level
      • To reduce oxygen to a sub-toxic level
    Chapter 5-4
  • 131. Types of Helium Mixes
    • What are the different types of helium mixes? Describe them.
      • Heliox - helium and oxygen
      • Trimix - helium, oxygen and nitrogen
        • Blended three basic ways
          • Standard trimix - helium, oxygen and air
          • Heliair - helium and air
          • Heliox - helium and enriched air nitrox
    Chapter 5-5
  • 132. Partial Pressure Blending Methods
    • List the steps required for mixing trimix, heliair and helitrox using partial pressure blending methods
    • Blending standard trimix with partial pressure
      • Calculate required oxygen, helium and air for desired blend
        • Chart, computer utility or formulas
      • Cascade required oxygen and helium into empty cylinder
        • Either may be first as required
    Chapter 5-6
  • 133. Partial Pressure Blending Methods
    • Blending standard trimix with partial pressure continued
      • Allow to cool and homogenize
        • Analyze to confirm accuracy
      • Top up with air to full pressure
      • Allow to cool and homogenize
        • Analyze to confirm accuracy
    Chapter 5-7
  • 134. Partial Pressure Blending Methods
    • Blending heliair trimix with partial pressure
      • Calculate required helium and air for desired blend
        • Chart, computer utility or formulas
      • Cascade required helium into empty cylinder
      • Top to desired pressure with air
      • Allow to cool and homogenize
        • Analyze to confirm accuracy
    Chapter 5-8
  • 135. Partial Pressure Blending Methods
    • Blending heliox with partial pressure
      • Calculate required helium and enriched air nitrox for desired blend
        • Chart, computer utility or formulas
      • Cascade helium into empty cylinders
      • Top up to desired pressure with required enriched air nitrox
      • Allow to cool and homogenize
        • Analyze to confirm accuracy
    Chapter 5-9
  • 136. Continuous Blending
    • Blending standard trimix using continuous blending
      • Requires 2
        • Oxygen analyzer and helium analyzer
      • Adjust helium, oxygen and air flow into mixing system until analyzers show desired blend
      • Gas from mixing system goes into compressor for pumping into cylinder
      • Mix is already homogenized
        • Analyze to confirm accuracy
    Chapter 5-10
  • 137. Continuous Blending
    • Blending heliair using continuous blending
      • Blends limited, but only oxygen analyzer required because of fixed oxygen nitrogen ratio
      • Flow air and helium into mixing system until analyzer shows O2 content for desired blend
        • Based on chart, formulas or computer utility
      • Gas from mixing system goes into compressor for pumping into cylinder
      • Mix is already homogenized
        • Analyze to confirm accuracy
    Chapter 5-11
  • 138. Continuous Blending
    • Blending heliox using continuous blending
      • Blends only limited by EANx available
        • Only oxygen analyzer required because of known oxygen nitrogen ratio
      • Flow air and helium into mixing system until analyzer shows O2 content for desired blend
        • Based on chart, formulas or computer utility
      • Gas from mixing system goes into compressor for pumping into cylinder
      • Mix is already homogenized
        • Analyze to confirm accuracy
    Chapter 5-12
  • 139. Oxygen Levels
    • What are the minimum oxygen levels required to sustain consciousness?
      • At the surface, 16% O2 is considered the minimum amount of oxygen required to sustain consciousness
      • If a mix has less than 18% O2, a travel gas is usually required until reaching a depth where the bottom mix has a PPO2 of .16 ata or higher
      • A certified trimix diver is trained to account for this issue
        • A normoxic trimix certification qualifies a diver to use only trimix with 21% oxygen
    Chapter 5-13
  • 140. Blending Helium-based Mixes
    • What are some of the issues unique to blending helium-based mixes?
      • Diver must be certified to use helium mixes
      • Trimix and Heliox require special tables/computes
        • Air/EANx procedures will not work
      • 1.6 ata is considered the maximum PPO2 (as with EANx)
      • Helium compresses differently from oxygen
        • Not a practical difference, but will cause minor variations in the final mix
    Chapter 5-14
  • 141. Blending Helium-based Mixes
      • Helium blends take more time to homogenize than EANx blends after partial pressure blending
        • Some blenders add top up air to 80% full pressure at a fairly high speed create turbulence
          • Allow to cool and top slowly to final pressure
          • Allow ample time to cool and homogenize
          • Make take up to 12 hours with doubles
    Chapter 5-15
  • 142. Blending Helium-based Mixes
      • Blending on top of partially full trimix becomes increasingly inaccurate without a helium analyzer
        • If you didn’t personally blend the previous trimix and don’t have a helium analyzer, always start with empty cylinders
    Chapter 5-16
  • 143. Blending Helium-based Mixes
      • It’s not recommended that you blend on top of partially full trimix more than once
        • If previous trimix was blended on partially filled trimix, drain cylinder
      • It’s generally recommended that you blend trimix into empty cylinders if you don’t have a helium analyzer
    Chapter 5-17
  • 144. Blending Helium-based Mixes
    • Analyzing with only an oxygen analyzer while partial pressure blending standard trimix
      • Determine helium, oxygen and air required for desired blend
        • Charts, formulas or computer utility
      • Fill cylinder with required O2 or helium (as preferred)
        • Allow to cool
        • Confirm pressure and analyze to confirm pure O2 or no O2
    Chapter 5-18
  • 145. Blending Helium-based Mixes
    • Analyzing with only an oxygen analyzer while partial pressure blending standard trimix continued
      • Add required helium or O2 (other gas)
        • Allow cylinders to cool and gases to homogenize
        • Analyze to confirm correct blend so far.
      • O2 pressure ÷ (O2 pressure + He pressure) = O2
      • Top up cylinder with air to desired working pressure
      • Allow to cool and mix to homogenize
      • Analyze to confirm
        • O2 should be within 1% of desired mix
    Chapter 5-19
  • 146. Blending Helium Mixes
    • Example #1 (Metric)
      • Desired blend TMx18/50 in 165 bar cylinder
      • Gases required: 16 bar O2, 67 bar air, 82 bar helium
      • Fill cylinder with 16 bar O2 (or 82 bar helium)
      • Allow cylinder to cool
        • Confirm pure O2 (or pure helium)
      • Fill cylinder with additional 82 bar helium (or 16 bar O2)
    Chapter 5-20
  • 147. Blending Helium Mixes
    • Example #1 continued (Metric)
      • Allow cylinder to cool and homogenize
        • Confirm pressure and analyze
      • O2 content should be 16%
      • 16 bar ÷ (16 bar + 82 bar) = .163
      • Top cylinder to 165 bar with air
      • Allow cylinder to cool and mix
      • Confirm pressure and analyze
        • Analysis should show 18% O2, plus or minus 1%
    Chapter 5-21
  • 148. Blending Helium Mixes
    • Example #2 (Imperial)
      • Desired blend TMx18/50 in 2400 psi cylinder
      • Gases required: 228 psi O2, 972 psi air, 1200 psi helium
      • Fill cylinder with 228 psi O2 (or 1200 psi helium)
      • Allow cylinder to cool
        • Confirm pure O2 (or pure helium)
      • Fill cylinder with additional 1200 psi helium (or 228 psi O2)
    Chapter 5-22
  • 149. Blending Helium Mixes
    • Example #2 continued (Imperial)
      • Allow cylinder to cool and homogenize
        • Confirm pressure and analyze
      • O2 content should be 16%
      • 228 psi ÷ (228 psi + 1200 psi) = .159
      • Top cylinder to 2400 psi with air
      • Allow cylinder to cool and mix
      • Confirm pressure and analyze
        • Analysis should show 18% O2, plus or minus 1%
    Chapter 5-23
  • 150. Chapter Five
    • Review
      • Using helium
      • Types of helium mixes
      • Partial pressure blending methods
      • Continuous blending
      • Oxygen levels
      • Blending helium-based mixes
    Chapter 5-24
  • 151. Chapter Five
    • Questions?
    Chapter 5-25
  • 152. Appendix Gas Blending Formulas
  • 153. Appendix
    • Overview
      • Calculate a Partial Fill
        • Example #1 (Metric)
        • Example #1 (Imperial)
        • Example #2 (Metric)
        • Example #2 (Imperial)
      • Calculate a Continuous Blending Fill
        • Example #1 (Metric)
        • Example #1 (Imperial)
        • Partial Pressure Blending
    Appendix -1
  • 154. Appendix
    • Overview continued
      • Using a Banked Mix and Topping with Air
        • Example # 1 (Metric)
        • Example #2 (Imperial)
      • Checking Your Work
        • Metric Calculations
        • Imperial Calculations
      • Gas Blending Tables
    Appendix -2
  • 155. Calculate a Partial Fill
    • How to calculate a partial pressure fill, starting with an empty tank:
      • Start with the amount of oxygen in the desired mix, which we express as the fraction of oxygen, or “FO2”
      • From this we subtract the fraction of oxygen in the ambient air, which is 21% (note that we express percentages as decimals)
    Appendix -3
  • 156. Calculate a Partial Fill
      • Divide the sum by the fraction of nitrogen in the ambient air, which is .79
      • Then multiply by the desired ending pressure in the cylinder
      • Desired FO2 - .21 (the amount of O2 in air) x Desired cylinder pressure .79 (the amount of N2 in air)
    Appendix -4
  • 157. Calculate a Partial Fill
    • Example #1 (Metric): A diver wants an EANx 32 in a steel 12 litre cylinder (160 bar pressure)
    • .32 is the desired O2 percentage in the final mix
    • .21 is the O2 percentage in air
    • .79 is the nitrogen percentage in air
    • 160 bar is the final pressure in the tank
    Appendix -5
  • 158. Calculate a Partial Fill
    • Calculation:
    • .32 - .21 x 160 = 22.3 bar
    • .79
    • 22.3 bar of pure O2 is required
    Appendix -6
  • 159. Calculate a Partial Fill
    • Example #1 (Imperial): A diver wants an EANx 32 in a steel 72 cubic foot cylinder (2400 psi pressure)
    • .32 is the desired O2 percentage in the final mix
    • .21 is the O2 percentage in air
    • .79 is the nitrogen percentage in air
    • 2400 is the final PSIG in the tank
    Appendix -7
  • 160. Calculate a Partial Fill
    • Calculation:
    • .32 - .21 x 2400 = 334
    • .79
    • 334 psi of pure O2 is required
    Appendix -8
  • 161. Calculate a Partial Fill
    • The partial pressure formula is also used if your top up gas is an EANx mixture
    • Simply change the fractions of oxygen and nitrogen to reflect the EANx gas percentages instead of those found in air
    Appendix -9
  • 162. Calculate a Partial Fill
    • Example #2 (Metric): A diver wants an EANx 40 in his 200 bar cylinder, and you have a bank of EANx 32
    • Calculation:
    • .40 - .32 x 200 = 23.5
    • .68
    Appendix -10
  • 163. Calculate a Partial Fill
    • .40 is the desired O2 percentage in the final mix
    • .32 is the O2 percentage in your bank bottles
    • .68 is the nitrogen percentage in your bank bottles (100% - 32%O2)
    • 23.5 is the final bar in the tank
    • 40 is the amount of additional O2 required
    Appendix -11
  • 164. Calculate a Partial Fill
    • Example #2 (Imperial): A diver wants an EANx 40 in his 3000 psig cylinder, and you have a bank of EANx 32
    • Calculation:
    • .40 - .32 x 3000 = 353
    • .68
    Appendix -12
  • 165. Calculate a Partial Fill
    • .40 is the desired O2 percentage in the final mix
    • .32 is the O2 percentage in your bank bottles
    • .68 is the nitrogen percentage in your bank bottles (100% - 32%O2)
    • 3000 is the final PSIG in the tank
    • 353 is the amount of additional O2 required
    Appendix -13
  • 166. Calculate a Continuous Blending Fill
    • How to calculate a continuous blending fill, starting with a partially full tank:
      • When continuously mixing, the oxygen content of the final mix is controlled by the fraction of oxygen introduced into the gas stream
      • Multiply the desired pressure in the tank by the desired fraction of oxygen to get the psig of O2 in the final mix
      • Multiply the present pressure in the tank by the existing fraction of oxygen to get the psig of O2 in the present mix
    Appendix -14
  • 167. Calculate a Continuous Blending Fill
    • continued
      • Subtract the present pressure from the desired pressure
      • Subtract the psig of O2 in the present mix from the psig in the desired/final mix
      • Divide the difference in O2 psig by the difference in the total psig
    Appendix -15
  • 168. Calculate a Continuous Blending Fill
    • Example #1 (Metric): A diver has 80 bar of EANx 32 and wants EANx 36 in a 200 bar cylinder
    • 200 x .36 = 72 (bar of O2 in final mix)
      • 80 x .32 = 25.6 (bar of O2 in present mix)
      • 120 46.4
      • (desired bar – present bar/desired O2 -present O2)
    • 46.4 = .386
    • 120
    Appendix -16
  • 169. Calculate a Continuous Blending Fill
    • 200 :final bar
    • .36 :desired O2 % in final mix
    • 80 :starting bar in tank
    • .32 :starting O2 % in the tank
    • 46.4 :difference in O2 required (in bar)
    • 120 :difference in total tank pressure required
    • .386 :O2 required in additional mix (38.6%)
    • Therefore , 38.6% of the 120 bar added to the tank must be O2. This diver’s tank would be topped with 120 bar of EANx38.6.
    Appendix -17
  • 170. Calculate a Continuous Blending Fill
    • Example 1 (imperial): A diver has 1200 psig of EANx 32 and wants EANx 36 in a 3000 psig cylinder.
    • 1) 3000 x .36 = 1080 (psig of O2 in final mix)
    • 1200 x .32 = 384 (psig of O2 in present mix)
    • 1800 696 (desired psi - present psi/desired O2 - present O2)
    • 2) 696 = .386
    • 1800
    Appendix -18
  • 171. Calculate a Continuous Blending Fill
    • 3000 :final psig
    • .36 :desired O2 % in final mix
    • 1200 :starting psig in tank
    • .32 :starting O2 % in the tank
    • 696 :difference in O2 required (in psi)
    • 1800 :difference in total tank pressure required
    • .386 :O2 required in additional mix (38.6%)
    • Therefore, 38.6% of the 1800 psi added to the tank must be O2, so this divers tank would be topped with 1800psig of EANx38.6
    Appendix -19
  • 172. Calculate a Partial Pressure Fill Starting with a Partially Full Tank
    • How would we do the previous scenario with partial pressure blending?
      • Use continuous blending formula to find the percentage of O2 required (FO2)
      • Simply plug the FO2 required (in this case 38.6%) into the partial pressure filling formula, that starts with an empty tank
    • In this case: .386 - .21 x 120 = 26.7
    • .79
    • .386 :O2 % in additional mix
    • .21 :O2 % in air
    • .79 :nitrogen % in air
    • 120 :difference in bar required
    • 26.7 :amount of additional O2 required
    Appendix -20
  • 173. Calculate a Partial Pressure Fill Starting with a Partially Full Tank
    • How would we do the previous scenario with partial pressure blending?
      • Use continuous blending formula to find the percentage of O2 required (FO2)
      • Simply plug the FO2 required (in this case 38.6%) into the partial pressure filling formula, that starts with an empty tank
    • In this case: .386 - .21 x 1800 = 401
    • .79
    • .386 :O2 % in additional mix
    • .21 :O2 % in air
    • .79 :nitrogen % in air
    • 1800 :difference in psi required
    • 401 :amount of additional O2 required
    Appendix -21
  • 174. Fill a Partially Full Tank, Using a Banked Mix, and Topping with Air
    • Example (Metric): A diver has 80 bar of EANx 32 and wants EANx 36 in a cylinder that has a working pressure of 200 bar. You have a banked mix of 40%
    • 200 x .36 = 72 (bar of oxygen in the final mix)
    • 80 x .32 = 25.6 (bar of oxygen in the present mix)
    • 120 46.4 (bar of oxygen to be added)
      • 200 is the final bar in the tank
      • .36 is the desired O2 percentage in the final mix
      • 80 is the starting bar in the tank
      • .32 is the starting O2 percentage in t he tank
      • 46.4 is the difference in the O2 required (in bar)
      • 120 is the difference in the total tank pressure required
    Appendix -22
  • 175. Fill a Partially Full Tank, Using a Banked Mix, and Topping with Air
    • Then , to calculate the amount of banked mix to be added:
    • 46.4 - (.21 x 120) = 111.6
    • .19
      • .19 is the O2 percentage difference between the bank mix (in this case, a 40% mix) and air (at .21)
      • 46.4 is the bar of O2 needed
      • 120 is the total bar to be added to the tank
      • 111.6 is the bar of bank mix to be added (in this case, a 40% bank mix)
    • Therefore , to properly fill this tank, you would add 111.6 bar of your 40% bank mix, and top with 8.4 bar of air (80 starting bar + 111.6 bank mix + 8.4 air = 200 bar total)
    Appendix -23
  • 176. Fill a Partially Full Tank, Using a Banked Mix, and Topping with Air
    • Example (Imperial): A diver has 1200 psig of EANx 32 and wants EANx 36 in a cylinder that has a working pressure of 3000 psig. You have a banked mix of 40%
    • 3000 x .36 = 1080 (psig of oxygen in the final mix)
    • 1200 x .32 = 384 (psig of oxygen in the present mix)
    • 1800 696 (psig of oxygen to be added)
      • 3000 is the final psig in the tank
      • .36 is the desired O2 percentage in the final mix
      • 1200 is the starting psig in the tank
      • .32 is the starting O2 percentage in t he tank
      • 696 is the difference in the O2 required (in psig)
      • 1800 is the difference in the total tank pressure required
    Appendix -24
  • 177. Fill a Partially Full Tank, Using a Banked Mix, and Topping with Air
    • Then , to calculate the amount of banked mix to be added:
    • 696 - (.21 x 1800) = 1673
    • .19
      • .19 is the O2 percentage difference between the bank mix (in this case, a 40% mix) and air (at .21)
      • 696 is the psig of O2 needed
      • 1800 is the total psig to be added to the tank
      • 1673 is the psig of bank mix to be added (in this case, a 40% bank mix)
    • Therefore , to properly fill this tank, you would add 1673 psig of your 40% bank mix, and top with 127 psig of air (1200 starting psig + 1673 bank mix + 127 air = 3000 psig total)
    Appendix -25
  • 178. Checking Your Work
    • Please Note:
      • If calculations show that the amount of bank mix to be added is greater than the total psig to be added, then some of the gas must be drained from the tank before starting
        • All calculations must be redone, based on the new starting pressure
      • The .19 in the previous calculation, will change, based on the bank mix being used
        • For example, if the bank mix being used is a 32% mix, then the .19 will change to .11 (which is calculated as .32 - .21, bank mix minus air)
    Appendix -26
  • 179. Checking Your Work
    • To check/confirm your calculations (Metric):
      • Calculate and compare the O2 in the final 36% mix:
        • 200 bar x .36 = 72 (bar O2 in .36% mix)
      • To the total of the components:
        • 111.6 bar x .40 = 44.6 (O2 in the 40% added)
        • 80 bar x .32 = 25.6 (O2 in starting mix)
        • 8.4 bar x .21 = 1.8 (O2 in top up air)
        • 200 bar 72 (Total bar O2 in mix)
    Appendix -27
  • 180. Checking Your Work
    • To check/confirm your calculations (Imperial):
      • Calculate and compare the O2 in the final 36% mix:
        • 3000 psig x .36 = 1080 (psig O2 in .36% mix)
      • To the total of the components:
        • 1673 psig x .40 = 669.20 (O2 in the 40% added)
        • 1200 psig x .32 = 384.00 (O2 in starting mix)
        • 127 psig x .21 = 26.27 (O2 in top up air)
        • 3000 psig 1079.87 (Total psig O2 in mix)
    Appendix -28
  • 181. Checking Your Work
    • Please Note:
      • It is always a good idea to double check all of your calculations:
        • Put your answers back into the formulas and see if they work out correctly
        • Compare the final answer(s) to a total of all the components
    Appendix -29
  • 182. Gas Blending Table Appendix -30
  • 183. Gas Blending Table Appendix -30
  • 184. Gas Blending Table Appendix -30
  • 185. Gas Blending Table Appendix -31
  • 186. Appendix
    • Review
      • Calculate a Partial Fill
        • Example #1 (Metric)
        • Example #1 (Imperial)
        • Example #2 (Metric)
        • Example #2 (Imperial)
      • Calculate a Continuous Blending Fill
        • Example #1 (Metric)
        • Example #1 (Imperial)
        • Partial Pressure Blending
    Appendix -32
  • 187. Appendix
    • Review continued
      • Using a Banked Mix and Topping with Air
        • Example # 1 (Metric)
        • Example #2 (Imperial)
      • Checking Your Work
        • Metric Calculations
        • Imperial Calculations
      • Gas Blending Tables
    Appendix -33
  • 188. Overall Program Goal
    • You are now aware of the accepted safety protocols and standards of blending breathing gases for diving
    • Go dive safely!
    Appendix -34
  • 189. Overall Program
    • Questions?
    Appendix -35

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