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Monday, December 14, 2009

Flange Bolting Dimensional Recomendation

Product
Carbon Steel
Alloy Steel
Stud bolts
ASME 818.2.1
ASME 818.2.1
Bolts smaller than 3/4 in.
ASME 818.2.1, square or
heavy hex head
ASME 818.2.1, heavy hex head
Bolts equal to or larger than 3/4 in.
ASME 818.2.1, square or hex head
ASME 818.2.1, heavy hex head
Nuts smaller than 3/4 in.
ASME 818.2.2, heavy hex
ASME 818.2.2, heavy hex
Nuts equal to or larger than 3/4 in.
ASME 818.2.2, hex or heavy hex
ASME B18.2.2, heavy hex
Male threads
ASME B1.1, Cl. 2A course series
ASME B1.1, Cl. 2A course
series up through 1 in.; eight thread series for larger bolts
Female threads
ASME B1.1, Cl. 28 course series
ASME Bl.1, Cl. 2B course series up through 1 in.; eight thread series for larger bolts

IPT's Industrial Fasteners Handbook (Bolting and Securing Systems)

Table : List of Bolting Specifications

Applicable ASTM Specifications (Notes 15)

Spec. No.
Grade
Notes
High Strength

( Note (2))
A193
B7
A193
B16
A320
L7
(10)
A320
L7A
(10)
A320
L7B
(10)
A320
L7C
(10)
A320
L43
(10)
A354
BC
A354
BD
A540
B21
A540
B22
A540
B23
A540
B24
Intermediate Strength

( Note (3))

A193
B5
A193
B6
A193
B6X
A193
B7M
A193
B8 CI.2
(11)
A193
B8C CI.2
(11)
A193
B8M CI.2
(11)
A193
B8T CI.2
(11)
A320
B8 CI.2
(11)
A320
B8C CI.2
(11)
A320
B8F CI.2
(11)
A320
B8M CI.2
(11)
A320
B8T CI.2
(11)
A449
(13)
A453
651
(14)
A453
660
(14)
Low Strength

( Note (4))
A193
B8 CI.1
(6)
A193
B8C CI.1
(6)
A193
B8M CI.1
(6)
A193
B8T CI.1
(6)
A193
B8A
(6)
A193
B8CA
(6)
A193
B8MA
(6)
A193
B8TA
(6)
A307
B
(12)
A320
B8 CI.1
(6)
A320
B8C CI.1
(6)
A320
B8M CI.1
(6)
A320
B8T CI.1
(6)
Nickel And Special Alloy

(Note (5))
B164
(7)(8)(9)
B166
(7)(8)(9)
B335
N10665
(7)
B408
(7)(8)(9)
B473
(7)
B574
N10276
(7)
GENERAL NOTE: Bolting material shall not be used beyond temperature limits specified in the governing code.

NOTES:
(1) Repair welding of bolting material is prohibited.
(2) These bolting materials may be used with all listed materials and gaskets.
(3) These bolting materials may be used with all listed materials and gaskets, provided it has been verified that a sealed joint can be maintained under rated working pressure and temperature.
(4) These bolting materials may be used with all listed materials but are limited to Classes 150 and 300 joints. See for required gasket practices.
(5) These materials may be used as bolting with comparable nickel and special alloy parts.
(6) This austenitic stainless material has been carbide solution treated but not strain hardened. Use A 194 nuts of corresponding material.
(7) Nuts may be machined from the same material or may be of a compatible grade of ASTM A 194.
(8) Maximum operating temperature is arbitrarily set at 5OO”F, unless material has been annealed, solution annealed or hot finished because hard temper adversely affects design stress in the creep rupture range.
(9) Forging quality not permitted unless the producer last heating or working these parts tests them as required for other permitted conditions in the same specification and certifies their final tensile, yield, and elongation properties to equal or exceed the requirements for one of the other permitted conditions.
(10) This ferritic material is intended for low temperature service. Use A 194 Grade 4 or Grade 7 nuts.
(11) This austenitic stainless material has been carbide solution treated and strain hardened. Use A 194 nuts of corresponding material.
(12) This carbon steel fastener shall not be used above 400°F or below -20°F. See also Note (4). Bolts with drilled or undersized heads shall not be used.
(13) Acceptable nuts for use with quenched and tempered bolts are A 194 Grades 2 and 2H. Mechanical property requirements for studs shall be the same as those for bolts.
(14) This special alloy is intended for high temperature service with austenitic stainless steel.
(15) ASME Boiler and Pressure Vessel Code, Section II materials, which also meet the requirements of the listed ASTM specifications, may also be used.
The 2009 Report on Aircraft and Aerospace Bolts of at Least 161 KSI Tensile Which Meet Specifications for Flying Vehicles Excluding Plastics: World Market Segmentation by City

Friday, December 11, 2009

Engineer - ETHICS

Engineering is considered to be a "profession" rather than an "occupation" because of several important characteristics shared with other recognized learned professions, law, medicine, and theology: special knowledge, special privileges, and special responsibilities. Professions are based on a large knowledge base requiring extensive training. Professional skills are important to the well-being of society. Professions are self-regulating, in that they control the training and evaluation processes that admit new persons to the field.
Professionals have autonomy in the workplace; they are expected to utilize their independent judgment in carrying out their professional responsibilities. Finally, professions are regulated by ethical standards. (Harris, C.E., M.S. Pritchard, & M.J. Rabins, Engineering Ethics: Concepts and Cases, Copyright 1995 by Wadsworth Publishing Company, pages 27.28
The expertise possessed by engineers is vitally important to public welfare. In order to serve the public effectively, engineers must maintain a high level of technical competence.
However, a high level of technical expertise without adherence to ethical guidelines is as much a threat to public welfare as is professional incompetence. Therefore, engineers must also be guided by ethical principles.
The ethical principles governing the engineering profession are embodied in codes of ethics. Such codes have been adopted by state boards of registration, professional engineering societies, and even by some private industries. An example of one such code is the NCEES Model Rules of Professional Conduct, which is presented here in its entirety.
As part of his/her responsibility to the public, an engineer is responsible for knowing and abiding by the code.
The three major sections of the model rules address (1) Licensee’s Obligations to Society, (2) Licensee’s Obligations to Employers and Clients, and (3) Licensee’s Obligations to Other Licensees. The principles amplified in these sections are important guides to appropriate behavior of professional engineers.
Application of the code in many situations is not controversial. However, there may be situations in which applying the code may raise more difficult issues. In particular, there may be circumstances in which terminology in the code is not clearly defined, or in which two sections of the code may be in conflict. For example, what constitutes "valuable consideration" or "adequate" knowledge may be interpreted differently by qualified professionals. These types of questions are called conceptual issues, in which definitions
of terms may be in dispute. In other situations, factual issues may also affect ethical dilemmas. Many decisions regarding engineering design may be based upon interpretation of disputed or incomplete information. In addition, tradeoffs revolving around competing issues of risk vs. benefit, or safety vs. economics may require judgments that are not fully addressed simply by application of the code.
No code can give immediate and mechanical answers to all ethical and professional problems that an engineer may face.
Creative problem solving is often called for in ethics, just as it is in other areas of engineering.
NCEES Model Rules of Professional Conduct
PREAMBLE
To comply with the purpose of the (identify jurisdiction, licensing statute) which is to safeguard life, health, and property, to promote the public welfare, and to maintain a high standard of integrity and practice the (identify board, licensing statute) has developed the following Rules of Professional Conduct. These rules shall be binding on every person holding a certificate of licensure to offer or perform engineering or land surveying services in this state. All persons licensed under (identify jurisdictions licensing statute) are required to be familiar with the licensing statute and these rules. The Rules of Professional Conduct delineate specific obligations the licensee must meet. In addition, each licensee is charged with the responsibility of adhering to the highest standards of ethical and moral conduct in all aspects of the practice of professional engineering and land surveying.
The practice of professional engineering and land surveying is a privilege, as opposed to a right. All licensees shall exercise their privilege of practicing by performing services only in the areas of their competence according to current standards of technical competence.
Licensees shall recognize their responsibility to the public and shall represent themselves before the public only in an objective and truthful manner.
They shall avoid conflicts of interest and faithfully serve the legitimate interests of their employers, clients, and customers within the limits defined by these rules. Their professional reputation shall be built on the merit of their services, and they shall not compete unfairly with others.
The Rules of Professional Conduct as promulgated herein are enforced under the powers vested by (identify jurisdictions enforcing agency). In these rules, the word “licensee” shall mean any person holding a license or a certificate issued by (identify jurisdictions licensing agency).
I. LICENSEE.S OBLIGATION TO SOCIETY
a. Licensees, in the performance of their services for clients, employers, and customers, shall be cognizant that their first and foremost responsibility is to the public welfare.
b. Licensees shall approve and seal only those design documents and surveys that conform to accepted engineering and land surveying standards and safeguard the life, health, property, and welfare of the public.
c. Licensees shall notify their employer or client and such other authority as may be appropriate when their professional judgment is overruled under circumstances where the life, health, property, or welfare of the public is endangered.
d. Licensees shall be objective and truthful in professional reports, statements, or testimony. They shall include all relevant and pertinent information in such reports, statements, or testimony.
e. Licensees shall express a professional opinion publicly only when it is founded upon an adequate knowledge of the facts and a competent evaluation of the subject matter.
f. Licensees shall issue no statements, criticisms, or arguments on technical matters which are inspired or paid for by interested parties, unless they explicitly identify the interested parties on whose behalf they are speaking and reveal any interest they have in the matters.
g. Licensees shall not permit the use of their name or firm name by, nor associate in the business ventures with, any person or firm who is engaging in fraudulent or dishonest business or professional practices.
h. Licensees having knowledge of possible violations of any of these Rules of Professional Conduct shall provide the board with the information and assistance necessary to make the final determination of such violation.
II. LICENSEE.S OBLIGATION TO EMPLOYER AND
CLIENTS
a. Licensees shall undertake assignments only when qualified by education or experience in the specific technical fields of engineering or land surveying involved.
b. Licensees shall not affix their signatures or seals to any plans or documents dealing with subject matter in which they lack competence, nor to any such plan or document not prepared under their direct control and personal supervision.
c. Licensees may accept assignments for coordination of an entire project, provided that each design segment is signed and sealed by the licensee responsible for preparation of that design segment.
d. Licensees shall not reveal facts, data, or information obtained in a professional capacity without the prior consent of the client or employer except as authorized or required by law.
e. Licensees shall not solicit or accept financial or other valuable consideration, directly or indirectly, from contractors, their agents, or other parties in connection with work for employers or clients.
f. Licensees shall make full prior disclosures to their employers or clients of potential conflicts of interest or other circumstances which could influence or appear to influence their judgment or the quality of their service.
g. Licensees shall not accept compensation, financial or otherwise, from more than one party for services pertaining to the same project, unless the circumstances are fully disclosed and agreed to by all interested parties.
h. Licensees shall not solicit or accept a professional contract from a governmental body on which a principal or officer of their organization serves as a member.
Conversely, licensees serving as members, advisors, or employees of a government body or department, who are the principals or employees of a private concern, shall not participate in decisions with respect to professional services offered or provided by said concern to the governmental body which they serve.
III. LICENSEE.S OBLIGATION TO OTHER
LICENSEES
a. Licensees shall not falsify or permit misrepresentation of their or their associates, academic or professional qualifications. They shall not misrepresent or exaggerate their degree of responsibility in prior assignments nor the complexity of said assignments. Presentations incident to the solicitation of employment or business shall not misrepresent pertinent facts concerning employers, employees, associates, joint ventures, or past accomplishments.
b. Licensees shall not offer, give, solicit, or receive, either directly or indirectly, any commission, or gift, or other valuable consideration in order to secure work, and shall not make any political contribution with the intent to influence the award of a contract by public authority.
c. Licensees shall not attempt to injure, maliciously or falsely, directly or indirectly, the professional reputation, prospects, practice, or employment of other licensees, nor indiscriminately criticize other licensees work.
Engineering Ethics: Concepts and Cases
Ethics in Engineering