 High Pressure Storage Of Permanent Gases Everest Kanto Cylinder Limited P.M.Samvatsar

Need for High Pressure Storage  We need to store, handle and transport higher quantity of gas in containers that are manageable.  Higher the pressure, larger is the quantity of gas contained in same cylinder volume.  Lighter the cylinder, more convenient and economical it is to handle it and transport it.  Larger cylinders banks offer less joints to make leak proof.  There are certain requirements which just cannot be serviced by liquefied gases. Everest Kanto Cylinder Limited P.M.Samvatsar 2

Why not Liquefied Gases?  Usually the liquefied gases containing, conveying and transportation is full of limitations which have so far kept them away from being universal solutions.  They call for specialized cryogenic vessels which need to be continuously monitored.  They also need special care while handling, unlike gas cylinders. This calls for persons with special training and skills  If the offtake of gas from cryo vessel is lower than the gas being generated due to heat seepage then the gas has to be released with resultant wastage. Such release is not possible for flammable gases.  So, there are majority of applications where only compressed gas cylinders are suitable. Everest Kanto Cylinder Limited P.M.Samvatsar 3

Why not Liquefied Gases? Everest Kanto Cylinder Limited P.M.Samvatsar 4

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Efficiency of Cylinders  The word Efficiency is used in cylinder industry for the amount of gas content for unit weight of cylinder.  So, cylinders which can contain higher pressure for lower weight are more efficient. They reduce the transportation costs substantially.  Permanent gases follow the Gas Equation o P 1 x V 1 / T 1 = P 2 x V 2 / T 2 o So, for higher gas content in fixed volume of cylinder, you need to get higher pressure in cylinder.  For this the cylinders have to be with materials with higher strength to get higher efficiency. Everest Kanto Cylinder Limited P.M.Samvatsar 6

Effect of Material properties on Gas Cylinders - 1 Technical Efficiency of Gas Cylinder Gas Volume Ratio of Cylinder Weight From the derivation given in the handout it would be clear that for a given diameter and length of cylinder, the Gas Volume is proportional to the pressure Cylinder weight is also proportional to the pressure But The cylinder weight depends on wall thickness which is inversely proportional to cylinder steel strength. Everest Kanto Cylinder Limited P.M.Samvatsar 7

Effect of Material properties on Gas Cylinders – 2 Conclusion : For a given water capacity and diameter of cylinder, the ratio of gas volume / cylinder weight i. e. technical efficiency remains constant and shall only be affected by material properties and density. So, to improve the technical efficiency of cylinders high strength steels have to be employed, with their limitation of intolerance for embrittling gases and stress corrosion cracking. Everest Kanto Cylinder Limited P.M.Samvatsar 8

Moving to Higher Pressures - 1  Advancements have come as a result of constant human desire to do things in a better way.  As far as gas cylinders are concerned it meant filling more gas in a cylinder.  Since the gases follow the Gas Equation, it means the cylinder has to be filled at increasingly higher pressures. This gives rise to two challenges o Developing suitable gas cylinders to work at these higher pressures. o Developing infrastructure of gas filling stations who are equipped to fill gas at these pressures. The development has been slow due to interdependence of the above two challenges Everest Kanto Cylinder Limited P.M.Samvatsar 9

Moving to Higher Pressures -2  Advancement in related fields is another driver for technology development. Aerospace imposed more exacting specifications for weight per unit volume of gas.  Another important driver is the Oil Crisis in Rising fuel costs required lighter cylinders with higher technical efficiency i.e. Free Volume of Gas / Weight of Cylinder. Moving to Higher Pressures Everest Kanto Cylinder Limited P.M.Samvatsar 10

Cylinder Evolution- 1  Cylinder designs mainly depend on the  capability of manufacturing of the Seamless Steel Tubes. The minimum thickness which could be produced. Secondly they depend on the development of suitable steels. The evolution was as below: Material of Cylinder Working pr Heat TreatmentYear o Carbon Steel: 70 to100 Bar Normalized 1910 o Carbon Mn Steel: 100 to 150 Bar Normalized/QT o Chrome Moly Steel:150 to 200 BarQT1960 o Chrome Moly Steel: 200 to 300 BarQT1990 o High Strength Steel: 200 to 300 BarQT1985 o High Strength Steel 300 to 400 BarQT1985 Everest Kanto Cylinder Limited P.M.Samvatsar 11

Cylinder Evolution- 2  Heat treatment choice depends on the minimum thickness available and working pressure required.  Even now, normalized cylinders are popular in small sizes because hot rolled tubes of lower thickness are not available and for the thickness, normalized steel can sustain the pressures particularly for Co 2. It makes cylinder more economical too.  Maneuverability is a consideration which drives the move to higher strength steels and / or different heat treatment.  50 ltr 300 Bar cylinder with standard CrMo steel would weight 95 kg against 67 kg of high strength steels.  At present the Indian standards for cylinders cover maximum tensile strength only upto 1100 MPa. Everest Kanto Cylinder Limited P.M.Samvatsar 12

Everest Kanto Cylinder Limited P.M.Samvatsar 13

High Strength Steels – Considerations- 1  The 300 bar cylinders were introduced in 1980s, they have become popular for certain applications because. o They could be used for majority of the gases which are classified as “Non-Embrittling” gases like Air, Nitrogen, Argon, Helium etc. o May need a VIPR – Valves with integrated pressure regulators to reduce pressure to 200 bar so that no change of equipment is necessary for downstream equipment. o They are already meeting additional tests to ascertain behaviour with flaw e.g. Flawed fatigue and burst test due to almost 50% higher stored energy leading to higher hazard level. They offer the same safety level as that of lower pressure cylinders in use. o While choosing the application the user has to understand that higher tensile and yield strengths affect the following adversely Toughness Ductility Corrosion resistance Fatigue resistance Stress Corrosion Cracking Everest Kanto Cylinder Limited P.M.Samvatsar 14

High Strength Steels – Considerations- 2  To meet these demands on steel they have to be o Refined – ESR and Re-melted steels o Addition of certain alloying elements o Close range of tolerances for each element in chemistry Should have: o Very low gas content o Very low Sulphur, Phosphorus, and Tin Content. o Fine grain o Very low inclusion rating Should be processed and tested with o Closely controlled heat treatment cycles o Ultrasonic flaw detection and other NDT techniques Everest Kanto Cylinder Limited P.M.Samvatsar 15

High Strength Steels – Considerations- 3  The manufacturer and the user has to take special care of the cylinder as the wall thickness is reduced with respect to the pressure and the margins are reduced so the tolerable flaw sizes also need to be limited to avoid accidents. Everest Kanto Cylinder Limited P.M.Samvatsar 16

Composite Cylinders  Considering the limitations of embrittling gases and weight issues normally what comes to mind is the option of using composite cylinders type 2, 3 and 4. o Type 1:All Steel o Type 2:Metal Liner with Hoop Wound Fiber Wrap o Type3:Metal Liner with Fully Wound Fiber Wrap o Type 4:Non Metal Liner with Fully Wound Fiber Wrap  However Composite Cylinders is not a panacea. They have limitations Higher cost,Careful handling or mounting Gas permeability Therefore they are not popular even though they are easily available. Everest Kanto Cylinder Limited P.M.Samvatsar 17

Bulk Transportation of Gases  For a safer and economical transportation of larger quantity of gases the cylinder bundles and cascades have emerged.  The cylinder assemblies are grouped as o Cylinder bundles – portable or floor mounted o Jumbo skids  The user always desires the least number of probable leak points to have utmost reliability. This could be achieved by using individual cylinder of large capacity e.g. The jumbo tubes which could have individual water capacity of 3000 ltr. Most popular is 2200 ltr 200/250 bar. Everest Kanto Cylinder Limited P.M.Samvatsar 18

Bulk Transportation of Gases Everest Kanto Cylinder Limited P.M.Samvatsar 19 EKC TUBE TRAILER

Bulk Transportation of Gases Everest Kanto Cylinder Limited P.M.Samvatsar 20

JOURNEY OF DEVELOPMENT  We have come a long way in means used for gas storage  Animal Bladders  Hammered and riveted vessels  Carbon steel seamless cylinders  Chromium Molybdenum steel seamless cylinders  High strength steel seamless cylinders  Composite cylinders  Who comes out as a trustworthy workhorse is of course is the Everest Kanto Cylinder Limited P.M.Samvatsar 21 STEEL CYLINDER

Techno Economic Considerations -1 Gas Carrying Comparison Chart Water Capacity (Litre) Pressure (Bar) Gas Capacity (m 3 ) Cylinder Weight (kg) No. of Cyls in 16T truck Total Gas Transported in 16T truck (m 3 ) % Extra Gas Carried vis-a- vis 150 Bar Technical Efficiency m 3 /kg Everest Kanto Cylinder Limited P.M.Samvatsar 22

Techno Economic Considerations -2 Investment Cost Comparison with 46.7 Litres – 150 Bar Cylinders With various Cylinders Pressure Ratings Water Capacity (Litre) Pressure Bar Gas Capacity (m 3 ) Investment per cyl (Rs) Investment / m3of Gas (Rs) % Advantage Everest Kanto Cylinder Limited P.M.Samvatsar 23

Cylinder Bundles / Quads / Cascades - 1  When two or more cylinders are held together in a frame and are also interconnected and connected to the outlet through manifold piping they are called Bundles, Quads, Cascades, Skids. They offer following advantages.  No labour is required for loading and unloading.  Cylinder valve or cylinder will not get damaged  Cylinder tracking/accounting will be easy and cylinders will not be lost  Cylinders can be easily identified for next test due date. Everest Kanto Cylinder Limited P.M.Samvatsar 24

Cylinder Bundles / Quads / Cascades - 2  50 Ltr 200 Bar Cylinders are very economical as compared to 46.7 Ltr 150 Bar cylinders. We get 10 m 3 gas as against 7 m 3 (based on what gas we fill)  Each bundle contains 12 cylinders so 120 m 3 gas. (in case of 46.7 ltr x 150 bar we get only 84 m 3 i.e. 43% more.  Ease of filling – 12 cylinders with single connection  No frequent cylinder changing by user Everest Kanto Cylinder Limited P.M.Samvatsar 25

Cylinder Bundles/ Quads / Cascades – 3 Everest Kanto Cylinder Limited P.M.Samvatsar 26

Cylinder Bundles / Quads / Cascades – 3 Everest Kanto Cylinder Limited P.M.Samvatsar 27

Cylinder Bundles/ Quads / Cascades – 3 Everest Kanto Cylinder Limited P.M.Samvatsar 28

Cylinder Bundles/ Quads / Cascades – 3 Everest Kanto Cylinder Limited P.M.Samvatsar 29

Cylinder Bundles/ Quads / Cascades – 3 Everest Kanto Cylinder Limited P.M.Samvatsar 30

Gas Delivery. Everest Kanto Cylinder Limited P.M.Samvatsar 31 Thanks for making a beginning over 1 ¼ century ago. Thanks for patient listening.