I N T R O D U C T I O N
T O
ASME CODES AND STANDARDS
Introduction Codes and Standards
From th e very found ing of t he American Society o f Mechanical Engineers (ASME International) in 1880, discussions were held on standards for shop drawing symbols, pulleys, and line shafting, machine screws, key seats, and drawing boards.
D ear Engineering Student:
With the ever-increasing industrialization, lack of The video yo u have just seen, “ An Introduction t o
interchangeability
also
became
a
problem.
Co des and Standards” , gave you a quick tour of the
Engineers realized the need for standardization
ASM E involvement in C odes and Standa rds.*
It
–the need to arrive at universal agreements on
ranged from the early impetus, given by the Sultana
how, for example, a consumer could buy a bolt in
and Baltimore Hydrant disasters, to the present sys-
California for a nut acquired in New Jersey, or
tem of standard writing, conformity assessment and
how a worn boiler connection could be easily
participation in ISO 9000.
replaced by a new one that would fit into place securely and sa fely. In 1883, a committee on stan-
This booklet expands on these issues so that you will become fully aware of the role codes and standards will play in your future professional life as a mechanica l engineer.
dards and gauges w as created. D uring the annual meeting of the Society in the same year, a paper was presented on the need to adopt a set of rules for conducting boiler tests which would be generally accepted among engineers as a standard code
Sincerely,
of pract ice. The paper empha sized the prevailing
Task G roup on Introduction t o ASM E Co des and
lack of uniformity in tha t “ every engineer w ho per-
Standards
forms a boiler test makes a rule for himself, which may be varied from time to time to suit the conve-
G erard G. Low en, Chairman
Ha lit M. Kosar
nience or interests of t he party fo r w hom the test is
Stuart Brown
Richard A. Merz
mad e.” This resulted in the format ion of a com-
Domenic A. Canonico
Mark Pagano
mittee to study the subject of a uniform test code.
John H. Fernandes
Sam Zamrik
Such a test code was published in 1884 and
Philip M. G erhart
became ASM E's first standa rd. Shortly thereafter, the Society decided that pipes and pipe threads should be standardized and that the standards committee should be composed of “ men representative of pipe manufacturers and pipe users, with
* For tho se who have not vi ew ed the video please contact A SM E
perhaps one representative of sprinkling systems
Cod es, Stand ards and Co nfo rm it y Assessment.
and certainly one of the manufacturers of taps and
Telepho ne: 1-21 2-59 1-85 00; Em ail :
[email protected]
dies.” Such an a pproach to ba lance came to typify the makeup of future ASME standards committees.
A I R H E A T E R S
A B B R E V I A T I O A N T S M O S A P C H C E R R I E C D W I T A A T T E I R O C N O O L A I I N R G C E O Q O U L I P E M D E N H T E A A T U E T X O C M H A A T I N C A G L E L R Y S F I R A E I D R B C O Y I L L E I R N S D E R B S A C A K N W D A T A E D R A V P A T L E V R E S S
C B E I N O T P R R I F O U C G E A S L S I P N U G M P E S Q U C I P H M A E R N T S T
C B H O E I M L I E R C A S L P B L A O N L T T S A N D B P U E I T L R D O I N L G E U S M E R R E V I F C I N E E S R Y P I P P I P I N I N G G C C A H S U T C I K N S G A S N A D N C D H F U O C R K G J I A N W G S S
Another serious problem facing engineers of that
years since the C ode w as introd uced – it speaks for
era w as exploding boilers. H eating w ater to pro-
itself.
duce steam a nd converting that steam into energy to power machinery revolutionized production in the
It is because of codes and standards that chains
nineteenth century.
To build up pressure, steam
and sprockets fit one another, plumbing fixtures
must be contained in some type of vessel and,
are interchangeable, elevators do not fall, nuts and
uncontrolled, pressurized steam can burst even one
bolts have uniform dimensions, power generation
mad e of steel. For wa nt of reliably tested mat erials,
equipment and industry in general operate safely
secure fittings, and proper valves, boilers of every
and economically.
description on land and at sea were exploding with terrifying regularity. They wo uld continue to do so into the tw entieth century. With the boiler test code as a beginning, the establishment of universally
What is a standard?
accepted construction standards would take many
A standard can be defined as a set of technical def-
years. Such stand ard s are toda y found in the ASM E
initions and guidelines-“ how to” instructions for
Boiler and Pressure Vessel Code.
designers and manuf acturers.
Standa rds, w hich
can run from a few paragraphs to hundreds of This Code, first published in 1915, is continually
pages, are written by experts.
revised and updated to keep pace with new materials, new designs, and new applications in fossil and
Standards are considered voluntary because they
nuclear plants. It has been ad opted as law in most
serve as guidelines, not having the force of law.
states of the USA as well as in Canada. Since the
ASME publishes its standards; accredits users of
development of this Code, boiler disasters have
standards to ensure that they are capable of man-
been reduced to almost none. After all, how many
ufacturing products that meet those standards; and
of you fa ll asleep at night w orrying that your home
provides stamps that accredited manufacturers
heater may explode?
place on their products, indicating that a product was manufactured according to a standard. ASME cannot, however, force any manufacturer, inspector, or installer to follow ASME standards. Their use is voluntary.
Figur e 1 NUMBER OF EXPLOSIONS
Why then are stand ard s effective?
400 350
Perhaps the
1991 Annual Report of the American Society for
300
Testing and M at erials (ASTM ) said it b est.
250
“ Standards are a vehicle of communication for
200 150
producers and users. They serve as a common la n-
100
guage, defining quality and establishing safety
50 0
Figure 1 shows a plot of boiler explosions versus 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 YEAR
C C R L A E N A N E O S U T S D E A C E O R A L A T P O U R L S V E R I D Z E E R F S I N I C T I O O M N P S R E A S N S D O R V S A L U C O E N S S U M D A E B N L S E I T T O Y O D L E S T E C R O M N I V N E A Y T O I R O S N C O D O E R R D R I I N C A K T E S M E D A I S A U L R I I N N G D M I C A A C T H O I N R E S S
D D I I M A E P N H S R I A O G N M I N S G E A A L N S D T D O I E L S E R A D N I C E I S N E G L A N D D I M B E U N R S N I O E N R S F U E D L R S A F T D I I G N G I T A L D S R Y A S I T N E S M S D U D M I B M W E N A S I I T O E N R A S L
criteria.
C osts are low er if procedures are stan-
da rdized; tra ining is also simplified.
And con-
Tolerancing, a ma nufacturer or fa bricato r is able to
sumers accept products more readily w hen they can
produce a part w ithout misunderstan ding.
be judged on intrinsic merit.”
contributes to the efficiency of modern manufactur-
This
ing by allowing different components of a product to be built in different parts of the world.
What is a code? A code is a standard that has been adopted by one or more governmental bodies and has the force of law, or when it has been incorporated into a business contract.
ASM E, th e American Society of Testing and Materials (ASTM), and the Society of Automotive Engineers (SAE) are just some of the 200 plus volunteer organizations in the United States that adhere to procedures accredited by the American National Standards Institute (ANSI) for the development of standa rds.
What is theinvolvement of ASME in codes and standards today?
These procedures must
reflect openness, transparency, balance of interest, and due process.
Since the beginning of industrialization, ASME and many other standards developing organizations
Committee meetings must be open to the public,
have worked to fulfill the growing need for stan-
and procedures are used to govern deliberations
da rds in today ’s w orld. Through a voluntary, con-
and voting. C ommittees must represent a bala nce
sensus process ASME standards are developed to
of interested parties, and all comments on technical
protect the health and welfare of the public.
documents during the final approval process must
In
addition to developing these standards ASME pro-
be considered.
vides confo rmity a ssessment processes wh ich help
action or inaction of a committee relating to mem-
to ensure that manufacturers live up to the relevant
bership, or a code or standard promulgated by the
specifications and that certain personnel are prop-
committee.
Any individual may appeal any
erly trained. ASME is one of the oldest and most respected stanThe ASM E Elevator C ode encompasses design and
dards developing organizations in the world. It pro-
installation of new equipment, maintenance, alter-
duces approximately 600 codes and standards, cov-
ation, and inspection; all with respect to the safety
ering a multitude of technical areas including boiler
of elevat ors, escalat ors, and related equipment. In
components, elevators, hand tools, fasteners, and
addition, ASME accredits organizations that certi-
machine tools. All of the items show n in the verti-
fy elevator inspectors.
cal sidebars of this boo klet represent t echnical a reas addressed by ASME codes and standards.
M E E J T E R C O T L O O R G S Y
Y14.5 Standard on G eometric Dimensioning and
Standards are also used to depict parts to be built and assembled, and to specify product drawings. By using a consistent system for drawing like the
F E L I T E T V I N A T G O S R S F L E A S N C G A E L S A T O F R L S O O R E X D H R A A U I N S S T E R S F L U F E A N G S A S F D A E S S T U E L N F E U R R S I Z A F T E I E O N D W A F T L E U R I D H E F A L T O E W R S I N F P I N I P E E S P A R F T I U C E U L L G A A T S E P M A I P T T I N E G R
G G A A S G T E U R B B L I N A E N K P S O W E G R A P G L E A N B T L S O C K G S A S T G U A R S B I N F E L S O W
COUNCIL ON C O D E S & S TA N D A R D S
BOARD ON PRESSURE TECHNOLOGY CODES & STANDARDS
BOARD ON
BOARD ON
BOARD ON
SAFETY CODES
PERFORMANCE
CONFORMITY
& STANDARDS
TEST CODES
ASSESSMENT
BOARD ON
BOARD ON
NUCLEAR CODES
STANDARDIZATION
& STANDARDS
G M A S E E A O S U U S R E F M U E E N L S T
METRICATION
BOARD ON
BOARD ON
INTERNATIONAL
HEARINGS
COUNCIL
STANDARDS
& APPEALS
OPERATIONS
BOARD ON
Figur e 2
G G A A S S K E T T S R A N G S A M U I G S E S I S O N G R A A N P D H I D C I S S Y T M R B I B O U L S T I O G N R P I N I D P I I N N G G
BOARD ON
How is ASME organized to producecodes and standards?
constant ly revised to reflect new developments and
Within ASME, the C ouncil on C odes and Standa rds
dard may come from individuals, committees, pro-
is one of five councils that report to the Board of
fessional organizations, government agencies,
G overnors. Under this C ouncil, as show n in Figure
industry groups, public interest groups, or f rom a n
2, there are six standards developing supervisory
ASME division or section.
boards and four advisory boards that manage over
referred to the appropriate supervisory board for
100 committ ees w ith 4000 volunteer members. The
consideration. The board th en assigns the request
supervisory boards are responsible for pressure tech-
to an existing committee of knowledgeable volun-
nology, nuclear installations, safety codes, perfor-
teers or determines that a new standards commit-
mance test codes, conformity assessment and stan-
tee must be formed.
dardization. The advisory boards deal with metri-
mittee has concluded that there is enough interest
cation, internationa l standa rds,
and need t he standa rds developing process is initi-
hearings and
technical ad vances. A request for a code or sta n-
The request is first
O nce an appropriat e com-
appeals and council operations.
ated.
Codes and standards are living documents that are
The standards committee is composed of engineers with knowledge and expertise in a particular field.
I H N A D N I C D A T T O E O L D S P O H W G I E H R L I F I T N T D R U U S C T K R S I A H L I G T H R U P C R E K S S S U A R N E D S Y V S E T H E I M C S L E H S O I S I T N S T E R H N O A O K L S C O H M Y B D R U O S E T L I E O C N T R E C I N G E I Q N U E I P G M E E N N T E R I A N T C O I R N E U R A N T I O T R S S
L I O I N N E C E O X N C V H E A N N T G I E O N E S Q A U N I D P M L E E N T T T E R J I N A G C K L S I N E K A E R Y M S E A S K U E Y R S E E M A E T N S T S K N P U L A R T L F I O N R G M L L E I F T T T S E R P S O Y R M T A B B O L L E S A U L T O I F M T O S T I V E L I L M I F I T T S I N G A N D D E V F I I C T E S
They represent users, manufacturers, consultants, universities, testing laboratories, and government regulato ry agencies.
The committee mainta ins a
balance of members in various interest classifications so that no one group domina tes. Volunteers must agree to adhere to the ASME Policy on Conflict of Interest and the Engineer’s Code of Ethics.
How does one find out whether there is a standard for a product? There are severa l different w ay s that engineers can find out whether there is an existing standard for a specific topic.
They can look in the ASME
Publications Catalog, the ANSI Catalog of American National Standards, the US government’s OSHA General Industry Standards, or contact a stand ard s orga nization directly. The internet may
Voting procedures for the standards committee are designed to ensure consensus as defined by ANSI. Balloting is conducted at meetings and votes are also sent by mail and email. Repeated voting may be necessary to resolve negat ive votes. If an individual member feels that due process was not
also be used as a resource for finding ASME standard s.
The
ASM E
online
cata log
at
htt p://w w w.a sme.org/cat alo g can be searched by keyword, standard designation or the International Standard Book N umber (ISBN).
observed, appeals may be made to the standards committee, supervisory board, and subsequently, to the Board on Hearings and Appeals. Once consensus has been reached, the proposed standard is then subjected to a public review in Mechanical Engineering magazine, and on the ASM E w eb site.
Anyone may submit comments
How do manufacturers and the public get involved? The first edition of the ASME Boiler and Pressure Vessel Code, published in 1915, provided for a stamp to be affixed to every product constructed in accordance with the Cod e.
during the public review period, to which the committee must respond. The dra ft is also submitted for a pproval to the supervisory bo ard and ANSI. When a ll considerations ha ve been sat isfied, the document is approved as an American National Standard and published b y ASME.
Tod ay, th e vario us boiler an d pressure vessel sta mps are recognized by most states and many foreign countries as indicative of products manufactured in compliance
with
the
Code
and
under
a quality program acceptable to the Society. A manufacturer obtains permission to use one of the stamps through the ASME conformity assessment process.
The manufa cturer’s qua lity control
system is review ed by an ASM E team. If it meets ASM E requirements a nd the ma nufacturer successfully demonstrates implementation of the program, the manufa cturer is accredited by ASME. The manufacturer then may certify the product as meeting ASME standards and apply the stamp to the product.
R P E O A W M E E R R E S D
P R L E A F T R F I O G E R R M A S T I F O O N R P B I U P I I N L G D I N G R E S M O A U I N R T C E E N R A E N C C O E V E R P Y R E F S A S C U I R L E I T Y V E O S P S E E R L A S T O R P S U M R P E S T A I Q N U I A N G L I R T I Y N G A S S S U R R A I V N E C T S E
S S T A A F I E N T L Y E S A S N D S T E E L
R E L I E F P I V P A E L V E S S T A S I C R W R A E Y W C T H H A R I E R A L D I S F T S S C R S E T W A S N D S S L I N S G T S E A M S - L G I E P N S E H R E A E T T I S N G S U P N R I A T Y S C O S O T L E I N E G L S S Y T S A T C E K M S S
A stamp consists of a modified cloverleaf (derived from the shape of the ASME logo) with one or mor e letters in the center.
The letters refer to
the type of equipment and the applicable code. See Figure 3.
ASM E sta mps issued are: A
–
FIELD ASSEMBLY OF POWER BOILERS
E
–
ELECTRIC BOILERS
H
–
HEATING BOILERS, STEEL PLATE OR CAST IRON SECTIONAL
–
HEATING BOILER SAFETY VALVES
HLW –
LINED POTABLE WATER HEATERS
HV
Figur e 3
ASME has accreditation programs for nuclear
M
–
MINI ATURE BOILERS
N
–
NUCLEAR POWER PLANT COMPONENTS
NPT –
PARTIALS
power plant materials, fasteners and, as stated earlier, organizations that certify elevator inspectors.
NA
–
ASME also is accredited to certify a company’s quality management system to ISO 9000 standards.
specified in ASM E stand ard s.
C urrent program s
NV
–
PP
–
PRESSURE PIPI NG
RP
–
REINFORCED PLASTIC PRESSURE VESSELS
ery fa cilities (municipal w aste comb usters), fossil RTP –
als. These programs include passing of w ritten or oral tests.
REINFORCED THERMOSET PLASTIC CORROSION RESISTANT EQUIPMENT
hazardous waste incinerators; and certification of geometric dimensioning and tolerancing prof ession-
NUCLEAR POWER PLANT SAFETY VALVES
include certification of operators of resource recovfuel fired plants, medical waste incinerators, and
NUCLEAR POWER PLANT INSTALLATION/ ASSEMBLY
Since 1992, ASME has certified individuals to recognize that they have met the qualification criteria
NUCLEAR POWER PLANT COMPONENT
S
–
POWER BOILERS
U,U2,U3 – PRESSURE VESSELS UD
–
RUPTURE DISC DEVICES
UM
–
MINI ATURE PRESSURE VESSELS
UV
–
PRESSURE VESSEL SAFETY VALVES
UV3 –
HIGH PRESSURE VESSEL SAFETY VALVES
V
–
BOILER SAFETY VALVES
T S H T E O R R M O A M G E E / T R E E R S T R I T E O V O A L L S M A T C R H A I N N S E M S I S S S I O T N O A R P A P G A E R T A A T U N S K S T R S A U N S R M F A I S C S E I O T N E C X T H U A R I N E S
T E M P E R A T U V R A E L M V E E S A S W U A R S E H M E E R N S T T U R B I N E S
S T W O A R S A T G E E F T A A C N I L K I S T Y W O P H E E R E A L T O D R O S L L I W E A S T E R W H H A I M R M L E P R O O A L R R B E A S T T H E T R U S B A W P E P I L G I H A I N N C G E S S C A W L E I S N D T W U E R L B D I E N D E A S L U W M I R N E U N M C H A L E L S O Y
Conclusion ASM E is one of a number of professional and technical organizations which, together, work to secure the fabric of the modern wo rld. The fact tha t the general public is unaware of their work is the best tribute to their achievement. The system of voluntary codes and standards has brought stability to the necessities of modern living. When you go to a movie, the projector in use is designed with standardized parts that fit together and a re easily replaced. Your radio, television set, VCR, telephone, computer, hand tools, and sports equipment–virtually all modern devices for personal improvement and amusement–involve one or more engineering standards. Invariably, those standards are scrupulously written and codified. And they are being rew ritten and improved by engineers and fellow professionals all the time.
The American Society of Mechanical Engineers Three Park Avenue, New York, NY 10016-5990
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