Hierarchy of Piping Design Documents
In today’s atmosphere of complex projects, extended liabilities, tight cost controls, and strict quality standards, it is essential that all phases of a project, from inception to operation, be effectively communicated and correctly executed. To this end, contract documents, design documents, fabrication details, procedures, and speciﬁcations are developed to communicate, monitor, and document the design, fabrication, and erection of piping systems precisely. The number and variety of documents to be prepared for a particular piping system are determined not so much by the importance of the piping system as by the complexity of the system and by the interface requirements of the owner, the design organization, the contractor, the material suppliers, and the regulatory agencies. In the following sections, the documentation requirements of a complex project are illustrated to provide a broad overview of the hierarchy of documents. However, since the speciﬁc requirements of a project are driven by many variables, such as the owner’s requirements, budgets,market conditions, company practice, and licensing requirements, the discussion here should be considered as a guideline only.
In this post all the principal design documents normally prepared for a complex piping system are identiﬁed, and their roles in the overall project are described. Note, however, that future developments in engineering tools might dictate variations from the documents described here. With the ongoing development of sophisticated computer software, several related design documents maybe developed from one database with the capability to extract information as required. For example, pressure drop and pipe stress analysis calculations may be executed from a physical piping drawings database.
The production and management of design documents may be inﬂuenced by outside parties. There are many industry and national standards that provide guidance in the preparation and control of design documents. Conformance to certain international standards is often mandatory. The references listed below contain standards for the preparation and control of design documents. The list is based on current practices in the United States. Where need for clarity exists, the reference is accompanied by a statement of ﬁeld of applicability. The list is not all-inclusive; engineers responsible for the preparation of design documents must, from time to time, review the current codes and standards in order to comply with and take advantage of the changes in the industry which are expected to continue as computerized drafting and preparation of text and record keeping improve. Additionally,where unique requirements exist, as in shipbuilding, the system design evolution process is governed by specialized methods. One reference is provided below for ship system design practice.
The military (MIL) and Department of Defense (DOD) standards and speciﬁcations referenced below provide a number of generally useful concepts and procedures for producing and maintaining design documents. Not all the information may be directly applicable to the ﬁeld of interest of this handbook; however, the referenced documents should not be ignored by anyone setting up a system of design document production and control because the information is of fundamental importance to an organized approach to the task.
ASME Boiler and Pressure Vessel Code, Section III, NCA-3252: Contents of Design Speciﬁcations. (The American Society of Mechanical Engineers, Three Park Avenue, New York, NY 10016–5990, USA.)
ANSI/ASME N626.3: Qualiﬁcations and Duties of Personnel Engaged in ASME Boiler and Pressure Vessel Code Section III, Division 1 and 2 Certifying Activities. (The American National Standards Institute, 11 West 42nd St., New York, NY 10036.)
U.S. Department of Defense Index of Speciﬁcations and Standards (DOD ISS). Naval Publication and Form Center ATT: NPODS, 5801 Tabor Avenue, Philadelphia, PA 19120–5099:
MIL-STD-481A Conﬁguration Control; Engineering Changes, Deviation and Waivers, Short Form
DOD-STD-480A Conﬁguration Control; Engineering Changes, Deviations and Waivers
MIL-STD-483A Conﬁguration Management Practices for Systems, Equipment, and Computer Programs
DOD-D-1000B Drawing, Engineering and Associated List
MIL-D-8501B Drawing, Undimensioned, Reproducibles, Photographic and Contact, Preparation of
ANSI Y14.1, to be ordered from ASME unless the request or is in the Navy
ANSI Y14.1, Drawing Sheet Size and Format (For ANSI ‘‘Y,’’ use ASME address.)
ANSI Y14.2, Line Conventions and Lettering. Drawings prepared under this standard usually are adequate for micro-graphic reproduction. (For ANSI ‘‘Y,’’use ASME address.)
ANSI Y14.5M, Dimensioning and Tolerancing (For ANSI ‘‘Y,’’ use ASME ad-dress.)
ISA-S5.1: Instrument Symbols and Identiﬁcation. This reference includes a standard for the amount of instrumentation detail that the piping designer would show on the piping and instrumentation diagram. The U.S. Nuclear Regulatory Commission has adopted a fairly current edition; users should verify that subsequent editions remain acceptable for U.S. nuclear work. (Instrument Society of America, 67 Alexander Drive, P.O. Box 12277, Research Triangle Park, NC 27709.)
NMA MS102, National Micrographics Association Drafting Guide for Micro-ﬁlm has been superseded by ANSI Y14.2, Line Conventions and Lettering, and by MS23. Contact the Association for Information and Image Management International, 1100 Wayne Ave., Silver Spring, MD 20910, for current information. Also, government regulations may dictate certain documentation requirements.
ISO 9000 Series Standards relating to quality control and quality assurance.
Harrington, Roy L., ed., Marine Engineering, Society of Naval Architects and Marine Engineers, Pavonia, NJ, 1992; ISBN 0-939773–10–4.
References 1 and 2 cover the ASME Code requirements for the Design Speciﬁcation and the certifying activities incidental to completion of the manufactured and erected work. References 3–8 have been required for some projects or they have been used as sources of guidance in the physical aspects of design and drafting.Reference 9 provides quality assurance and control requirements, which are being speciﬁed increasingly for piping and other equipment, including services. References 10 and 11 contain information on piping design and the design process itself.
In the United States, federal, state, and local laws apply to various piping systems; in other countries, similar laws may prevail. For example, the U.S. Code of Federal Regulations (CFR), Title 10, Part 50 mandates strict requirements for the design, construction, and operation of piping systems in a nuclear production or utilization facility. State and local governments generally invoke the ASME B31, Pressure Piping Code (Section B31.1 for Power Piping; B31.3 for Process Piping; etc.); and the ASME Boiler and Pressure Vessel Code (Section I, Power Boilers; Section II, Materials; etc.). Laws aimed at protecting the environment may also impact the design of some systems. Parts of the International Standards Organization (ISO) requirements, Ref. 9, are often imposed on piping design projects worldwide. The designer becomes familiar with the regulations prevailing at the location of the project by independent research and conference with the owner and local authorities.
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