Steel Pressure Vessel

A pressure vessel is a closed, rigid container designed to hold gases or liquids at a pressure different from the ambient pressure. The end caps fitted to the cylindrical body are called heads. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ... The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ... Steel Pressure Vessel The end caps on a cylindrically shaped Pressure vessel are commonly known as heads. ...

In addition to industrial compressed air receivers and domestic hot water storage tanks, other examples of pressure vessels are: diving cylinder, recompression chamber, distillation towers and many other vessels in oil refineries and petrochemical plants, nuclear reactor vessel, habitat of a space ship, habitat of a submarine, pneumatic reservoir, hydraulic reservoir under pressure, rail vehicle airbrake reservoir, road vehicle airbrake reservoir and storage vessels for liquified gases such as ammonia, chlorine, propane, butane and LPG. 12 litre and 3 litre steel diving cylinders A diving cylinder or SCUBA tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ... A recompression chamber is a pressure vessel used to treat divers suffering from certain diving disorders such as decompression sickness. ... Fractional distillation is the separation of a mixture into its component parts, or fractions, such as in separating chemical compounds by their boiling point by heating them to a temperature at which several fractions of the compound will evaporate. ... View of Shell Oil Refinery in Martinez, California. ... Petrochemicals are chemical products made from raw materials of petroleum (hydrocarbon) origin. ... Core of a small nuclear reactor used for research. ... Ariane 5 lifts off with the Rosetta probe on 2nd of March, 2004. ... German UC-1 class World War I submarine A model of Günther Priens Unterseeboot 47 (U-47), German WWII Type VII diesel-electric hunter Typhoon class nuclear ballistic missile submarine USS Virginia, a Virginia-class nuclear attack (SSN) submarine A submarine is a watercraft that can operate underwater... Pneumatics, from the Greek πνευματικός (pneumatikos, coming from the wind) is the use of pressurized air in science and technology. ... Hydraulics is a branch of science and engineering concerned with the use of liquids to perform mechanical tasks. ... Piping diagram from 1920 of a Westinghouse E-T Air Brake system. ... George Westinghouse first developed air brakes for use in railway service. ... Ammonia is a compound with the formula NH3. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... Propane is a three-carbon alkane, normally a gas, but compressible to a liquid that is transportable. ... Butane, also called n-butane, is the unbranched alkane with four carbon atoms, CH3CH2CH2CH3. ... 45 kg LPG cylinders Spherical Gas Container typically found in Refineries. ...

In the industrial sector, pressure vessels are designed to operate safely at a specific pressure and temperature, technically referred to as the "Design Pressure" and "Design Temperature". A vessel that is inadequately designed to handle a high pressure constitutes a very significant safety hazard. Because of that, the design and certification of pressure vessels is governed by design codes such as the ASME Boiler and Pressure Vessel Code in North America, the Pressure Equipment Directive of the EU (PED), Japanese Industrial Standard (JIS), CSA B51 in Canada and other international standards like Lloyd's, Germanischer Lloyd, Det Norske Veritas, Stoomwezen etc. The American Society of Mechanical Engineers (ASME) is a professional body, specifically an engineering society, focused on mechanical engineering. ... The Pressure Equipment Directive 97/23/EC (PED) of the EU sets out the standards for the design and manufacture of pressure equipment generally over 1 litre in volume and having a maximum pressure more than 0. ... Japanese Industrial Standards (JIS) specifies the standards used for industrial activities in Japan. ... CSA Logo with C and US Established in 1919, the Canadian Standards Association (CSA) is a world leader in safety standards testings. ... Standards are produced by many organizations, some for internal usage only, others for use by a groups of people, groups of companies, or a subsection of an industry. ... The Lloyds Register Group is an independent risk management organisation providing risk assessment and risk mitigation solutions and management systems certification. ... The Germanischer Lloyd AG is a classification society founded in 1867. ... DNV or Det Norske Veritas is a Norwegian company established in 1864. ...

Shape of a pressure vessel

Theoretically a sphere would be the optimal shape of a pressure vessel. Most pressure vessels are made of steel. To manufacture a spherical pressure vessel, forged parts would have to be welded together. Some mechanical properties of steel are increased by forging, but welding can sometimes reduce these desirable properties. In case of welding, in order to make the pressure vessel meet international safety standards, carefully selected steel with a high impact resistance should be used. Most pressure vessels are arranged from a pipe and two covers. Disadvantage of these vessels is the fact that larger diameters make them relatively more expensive, so that for example the most economic shape of a 1000 litres, 250 bar pressure vessel might be a diameter of 450 mm and a length of 6500 mm.

Scaling

No matter what shape it takes, the minimum mass of a pressure vessel scales with the pressure and volume it contains. For a sphere, the mass of a pressure vessel is A sphere is a perfectly symmetrical geometrical object. ...

Where M is mass, p is pressure, V is volume, ρ is the density of the pressure vessel material, and σ is the maximum working stress that material can tolerate. Other shapes besides a sphere have constants larger than 3/2, although some tanks, such as non-spherical wound composite tanks can approach this. Stress is the internal distribution of force per unit area that balances and reacts to external loads applied to a body. ...

As can be seen from the equation, there is no theoretical efficiency of scale to be had in a pressure vessel; and further, for storing gases, tankage efficiency can be easily shown to be independent of pressure.

So, for example, a typical design for a minimum mass tank to hold helium (as a pressurant gas) on a rocket would use a spherical chamber for a minimum shape constant, carbon fiber for best possible ρ / σ, and very cold helium for best possible M / pV.

A spherical tank has less surface area for a given volume than any other tank shape. Also, the hoop stress in the wall of a sphere is half that of a cylinder at the same pressure.^{[citation needed]} Thus if the walls are made of the same material, the spherical tank can hold twice the pressure of the cylindrical tank, or at the same pressure, the spherical tank wall can be half the thickness.^{[citation needed]} Hoop stress is mechanical stress applied in a direction perpendicular to the radius of the item in question. ... A right circular cylinder An elliptic cylinder In mathematics, a cylinder is a quadric surface, with the following equation in Cartesian coordinates: This equation is for an elliptic cylinder, a generalization of the ordinary, circular cylinder (a = b). ...

Stress in thin-walled pressure vessels

The stress in a thin-walled pressure vessel in the shape of a sphere is:

Where σ_θ is the hoop stress, or stress in the radial direction, p is the internal gage pressure, r is the radius of the sphere, and t is the thickness. A vessel can be considered "thin-walled" if the radius is at least 20 times larger than the wall thickness.^[1]

The stress in a thin-walled pressure vessel in the shape of a cylinder is:


Where σ_θ is the hoop stress, or stress in the radial direction, σ_long is the stress in the longitudinal direction, p is the internal gage pressure, r is the radius of the cylinder, and t is the wall thickness.

See also

• Water-tube boiler
• Fire-tube boiler
• Safety valve
• Relief valve
• Gas cylinder
• Bottled gas
• BS 4994
• ASME Code Section VIII Division 1
• ASME Code Section VIII Division 2 Alternative Rule
• ASME Code Section VIII Division 3 Alternative Rule for Construction of High Pressure Vessel
• ASME Stamp

Schematic diagram of a marine-type water tube boiler A water-tube boiler is a type of boiler in which water circulates in tubes which are heated externally by the fire. ... A fire-tube boiler is a type of boiler in which hot gases from the fire pass through one or more tubes within the boiler. ... This article or section does not cite its references or sources. ... Relief Valve A relief valve opens to release excess pressure when the pressure is too high to protect the vessel or other equipment from overpressurization. ... Industrial compressed gas cylinders used for oxy-fuel welding and cutting of steel. ... Bottled gas is a term used for substances which are gasous at Standard temperature and pressure (STP) and have been compressed and stored in steel or composite bottles known as gas cylinders. ... BS4994 (formally: British Standard 4994:1987) is the specification for the design and construction of vessels and storage tanks in reinforced plastics. It specifies a code of practice for use by manufacturers of such containers. ...

External links

*Pressure Equipment Engineering Services, Inc.

Further reading

• Megyesy, Eugene F. (2004, 13th ed.) Pressure Vessel Handbook. Pressure Vessel Publishing, Inc.: Tulsa, Oklahoma, USA. Design handbook for pressure vessels based on the ASME code.

References

• A.C. Ugural, S.K. Fenster, Advanced Strength and Applied Elasticity, 4th ed.
• E.P. Popov, Engineering Mechanics of Solids, 1st ed.

1. ^ Richard Budynas, J. Nisbett, Shigley's Mechanical Engineering Design, 8th ed., New York:McGraw-Hill, ISBN 978-0-07-312193-2, pg 108