Vessel code

Vendor or vessel engineer will fill in mechanical details of the vessel on the data eet III. The Basic Features of Vessel III.I Vessel code 

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ASME Code, Article II, Subsection A, Section V, Boiler and Pressure Vessel Code, 1983. 

J. ASME XI Boiler and Pressure Vessel code. Appendix III "Ultrasonic examination of piping systems ... 

ASME Boiler and Pressure Vessel Code. The ASME Boiler and Pressure Vessel Code is pubhshed in 11 sections. Section VIII, which is concerned with rules for the design of unfired pressure vessels, was first pubhshed in 1925 and since 1968 it has been issued in two parts. Division 1 (147) and Division 2 (148), the latter being known as the Alternative Rules. 

ASME Boi/er and Pressure Vessel Code, Seetion 8, Pules for Construetion of Pressure Vessels, ASME, New York, 1989. 

The American Society of Mechanical Engineers (ASME) United Engineering Center 345 East 47th Street New York, NY 10017 The ASME Boiler and Pressure Vessel Code, under the cognisance of the ASME PoHcy Board, Codes, and Standards, considers the interdependence of design procedures, material selection, fabrication procedures, inspection, and test methods that affect the safety of boilers, pressure vessels, and nuclear-plant components, whose failures could endanger the operators or the pubHc (see Nuclearreactors). It does not cover other aspects of these topics that affect operation, maintenance, or nonha2ardous deterioration. 

Pressure- Vessel Standards. Explosion-clad plates for pressure vessels are tested according to the appHcable ASME Boiler and Pressure Vessel Code Specifications. Unfired pressure vessels using clads are covered by ASTM A263, A264, and A265 these include tensile, bend, and shear tests (see Tanks AND pressure vessels). 

Rules for Nuclear Power piping are in Section 3 of the ASME Boiler Pressure Vessel Code. 

Pressure Vessels and Piping. Some of the most critical components of a chemical plant involve pressure vessels. A thorough knowledge of the American Society of Mechanical Engineers (ASME) Pressure Vessel Code (75) is essential for design and maintenance of chemical plants. Some states have their own codes, which usually conform closely to the ASME version (see High pressure technology Tanks and pressure vessels). 

Boiler and Pressure Vessel Code, Sect. VIII, American Society of Mechanical Engineers, New York, 1995. 

The most fundamental limitation on pressure is at 15 psig (101.4 kPa). Containers built to pressures exceeding this value are usuaHy caHed pressure vessels and are covered by the American Society of Mechanical Fngineers (ASME) Boiler and Pressure Vessel Code. For aH practical purposes, tanks are defined to have internal pressures below this value. 

Careflil material selection is required to prevent brittle failure of tanks at low temperatures. In addition, for tanks where the service temperatures are reduced, it is essential that an engineering analysis be performed to ensure that the tanks are not subject to brittle failure at the house temperature. The tank and vessel codes usually specify allowable materials based on design temperature. Further information about selection of metals for low temperature is available (8). 

Zirconium is used as a containment material for the uranium oxide fuel pellets in nuclear power reactors (see Nuclearreactors). Zirconium is particularly usehil for this appHcation because of its ready availabiUty, good ductiUty, resistance to radiation damage, low thermal-neutron absorption cross section 18 x 10 ° ra (0.18 bams), and excellent corrosion resistance in pressurized hot water up to 350°C. Zirconium is used as an alloy strengthening agent in aluminum and magnesium, and as the burning component in flash bulbs. It is employed as a corrosion-resistant metal in the chemical process industry, and as pressure-vessel material of constmction in the ASME Boiler and Pressure Vessel Codes. 

Where the word code is rrsed in this srrbsection of the Handbook withorrt other identification, it refers to the B31.3 section of ANSI B31. The code has been extensively qrroted in this srrbsection of the Handbook with the permission of the prrblisher. The code is prrbhshed by and copies are available from the American Society of Mechanical Engineers (ASME), 345 East 47th Street, New York, New York 10017. References to the ASME code are to the ASME Boiler and Pressrrre Vessel Code, also prrblished by the American Society of Mechanical Engineers. 

B31.7 Nuclear Power Piping For fluids whose loss from the system could cause radiation hazard to plant personnel or the general pubhc Withdrawn see ASME Boiler and Pressure Vessel Code, Sec. 3... 

A product used under the jurisdiction of the ASME Boiler and Pressure Vessel Code and the ANSI Code for Pressure Piping B31.1 is subject to any limitation of those codes. This includes any maximum-temperature limitation for a material or a code rule governing the use of a material at a low temperature. 

When the anticipated number of cycles is substantially less than 7000, useful information can be obtained from ASME Boiler and Pressure Vessel Code, Sec. Ill, Nuclear Vessels. ... 

For flanges of nonstandard dimensions or for sizes beyond the scope of the approved standards, design shall be in accordance with the requirements of the ASME Boiler and Pressure Vessel Code, Sec. T11, except that requirements for fabrication, assembly, inspection testing, and the pressure and temperature hmits for materials of the Piping Code are to prevail. Countermoment flanges of flat face or otherwise providing a reaction outside the bolt circle are permitted if... 

As the size or the pressure goes up, curvature on all surfaces becomes necessary. Tariks in this category, up to and including a pressure of 103.4 kPa (15 Ibf/in"), can be built according to API Standard 620. Shapes used are spheres, ellipsoids, toroidal structures, and circular cylinders with torispherical, elhpsoidal, or hemispherical heads. The ASME Pressure Vessel Code (Sec. TII of the ASME Boiler and Pressure Vessel Code), although not required below 103.4 kPa (15 Ibf/in"), is also useful for designing such tanks. 

Tanks that could be subjected to vacuum should be provided with vacuum-breaking valves or be designed for vacuum (external pressure). The ASME Pressure Vessel Code contains design procedures. 

The standard dished head does not comply with the ASME Pressure Vessel Code. 

Petroleum pipe hues before 1969 were built to ASA (now ANSI) Standard B31.4 for liquids and Standard B31.8 for gas. These standards were seldom mandatoiy because few states adopted them. The U.S. Department of Transportation (DOT), which now has responsi-bihty for pipe-line regulation, issued Title 49, Part 192—Transportation of Natural Gas and Other Gas by Pipeline Minimum Safety Standards, and Part 195—Transportation of Liquids by Pipehne. These contain considerable material from B31.4 and B31.8. They allow generally higher stresses than the ASME Pressure Vessel Code would allow for steels of comparable strength. The enforcement of their regulations is presently left to the states and is therefore somewhat uncertain. 

A difference between tank cars and most pressure vessels is that tank cars are designed in terms of the theoretical ultimate or bursting strength of the tank. The test pressure is usually 40 percent of the bursting pressure (sometimes less). The safety valves are set at 75 percent of the test pressure. Thus, the maximum operating pressure is usually 30 percent of the bursting pressure. This gives a nominal factor of safety of 3.3, compared with 4.0 for Division 1 of the ASME Pressure Vessel Code. 

Truck cargo tanks (for dangerous materials) are built under Part 173 and Siibpart J of Part 178, DOT regulations. This includes Specifications MC-306, MC-307, MC-312, and MC-331. MC-331 is required for compressed gas. Siibpart J requires tanks for pressures aoove 345 kPa (50 Ibf/in ) in one case and 103 kPa (15 Ibf/in ) in another to be built according to the ASME Pressure Vessel Code. A particular issue of the code is specified. 

Code Administration The American Society of Mechanical Engineers has written the ASME Boiler and Pressure Vessel Code, which contains rirles for the design, fabrication, and inspection of boilers and pressure vessels. The ASME Code is an American National Standard. Most states in the United States and all Canadian provinces have passed legislation which makes the ASME Code or certain parts of it their legal requirement. Orrly a few jurisdictions have adopted the code for all vessels. The others apply it to certain types of vessels or to boilers. States employ inspectors (usually under a chief boiler inspector) to enforce code provisions. The authorities also depend a great deal on insurance company inspectors to see that boilers and pressure vessels are maintained in a safe condition. 

Inspection Authority The National Board of Boiler and Pressure Vessel Inspectors is composed of the chief inspectors of states and municipalities in the United States and Canadian provinces which have made any pari of the Boiler and Pressure Vessel Code a legal requirement. This board promotes uniform enforcement of boiler and pressure-vessel rules. One of the board s imporiant activities is providing examinations for, and commissioning of, inspectors. Inspeciors so qualified and employed by an insurance company state, municipality, or Canadian province may inspect a pressure vessel and permit it to be stamped ASME—NB (National Board). An inspector employed by a vessel user may authorize the use of only the ASME stamp. The ASME Code Committee authorizes fabricators to use the various ASME stamps. The stamps, however, may be apphed to a vessel only with the approval of the inspector. 

The ASME Boiler and Pressure Vessel Code consists of eleven sections as follows ... 

Pressure Vessel Code as it existed in the past (and will continue). Division 2 was brought out as a means of permitting higher design stresses while ensuring at least as great a degree of safety as in Division I. These two divisions plus Secs. HI and X will be discussed briefly here. They refer to Secs. II and IX. 

Vessel Codes Other Than ASME Different design and construction rules are used in other countries. Chemical engineers concerned with pressure vessels outside the United States must become familiar with local pressure-vessel laws and regulations. Boilers and Pressure Vessels, an international survey of design and approval requirements published by the British Standards Institution, May-lands Avenue, Hemel Hempstead, Hertfordshire, England, in 1975, gives pertinent information for 76 political jurisdic tions. 

The National Board Inspection Code, published by the National Board of Boiler and Pressure Vessel Inspectors, Columbus, Ohio, is helpful. Any repair, however, is acceptable if it is made in accordance with the rules of the Pressure Vessel Code. 

Construction Codes Rules for Construction of Pressure Vessels, Division 1, which is part of Section T11 of the ASME Boiler and Pressure Vessel Code (American Society of Mechanical Engineers), sei ves as a construction code by providing minimum standards. New editions of the code are usually issued every 3 years. Interim revisions are made semiannually in the form of addenda. Compliance with ASME Code requirements is mandatoiy in much of the United States and Canada. Originally these rules were not prepared for heat exchangers. However, the welded joint between tube sheet and shell of the fixed-tube-sheet heat exchanger is now included. A nonmandatoi y... 

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