Design Standards, Specifications and Codes
Plastics and Composites.
Some notes are provided here on standards used in the manufacture of composites and reinforced plastics and the polymer and plastics materials used in their manufacture. We maintain recent versions in our digital library, where possible. Clients should check the specific year of publication, if a standard is stipulated by a customer. It is recommended to study the requirements of specific standards before making any of them, or any parts of any of them, mandatory. The following list, although comprehensive is by no means exhaustive, but it includes the ones most commonly encountered. We will expand our listing of standards and the discussion of them as required. Some standards applying to steel items and steel fabrication methods are included, where they are applied to items used in the plastics and composites industry.
ASME RTP-1 Reinforced Thermoset Plastic Corrosion Resistant Equipment
ASME RTP-1 is an American National Standard published by the American Society of Mechanical Engineers. This standard provides a lot of guidance for establishing design requirements for vessels up to 15 psig (1.03 bar) of the type being considered, including shell design, flange design, anchoring etc. This standard might be considered the easiest to work with, but uses American customary units.
ASME Boiler and Pressure Vessel Code Section X Fiber-Reinforced Plastic Pressure Vessels
The American Society of Mechanical Engineers developed a special section of the Pressure Vessel Code to cover the construction of pressure vessels made from composite materials. We quote part of the introduction to this standard to illustrate the particular concerns in this type of design work: “The use of fiber-reinforced plastics for the manufacture of pressure vessels presents unique materials considerations in the design, fabrication, and testing of these vessels. Metallic vessels, being made from materials which are normally isotropic and ductile, are designed by using well-established allowable stresses based on measured tensile and ductility properties. In contrast, fiber-reinforced plastics are usually anisotropic and the physical properties are dependent upon the fabrication process, the placement and orientation of the reinforcement, and the resin matrix.”
ASME PVHO-1, Safety Standard for Pressure Vessels for Human Occupancy
Early in 1971, an ad hoc committee was formed by action of the ASME Codes and Standards Policy Board to develop design rules for pressure vessels for human occupancy. The importance of this task was soon recognized, and the ASME Safety Code Committee on Pressure Vessels for Human Occupancy (PVHO) was established in 1974 to continue the work of the ad hoc committee. Initially, this committee was to confine its activity to the pressure boundary of such systems. It was to reference existing ASME Boiler and pressure Vessel Code (BPVC) Sections, insofar as practicable, adapting them for application to pressure vessels for human occupancy. The common practice hitherto had been to design such chambers in accordance with Section VIII, Division 1 of ASME BPVC; however, a number of important considerations were not covered in those rules. Among these were requirements for viewports and the in-service use of pressure relief valves, and special material toughness requirements. This Standard provides the necessary rules to supplement that Section, and also Section VIII, Division 2 of ASME BPVC. The user is expected to be familiar with the principles and application of the Code Sections.
ASME BPVC criteria furnish the baseline for design. In ASME PVHO-1, design temperature is limited to 0°F to 150°F (−18°C to 66°C). Supporting structure and lifting loads are given special attention. Certain design details permitted by Section VIII are excluded. A major addition is the inclusion of design rules for acrylic viewports Section 2). The formulation of rules for these vital and critical appurtenances was one of the reasons for establishing the PVHO Committee. Finally, all chambers designed for external pressure are required to be subjected to an external pressure hydrostatic test or pneumatic test.
ASME PVHO-2, Safety Standard for Pressure Vessels for Human Occupancy: In-Service Guidelines
In 1998 a PVHO Task Group was formed to investigate the need for In-Service Rules and Guidelines for Pressure Vessels for Human Occupancy. Simultaneously, a Sub Task Group was formed to investigate the issue of acrylic window design life versus service life. The design life is based on the PVHO window being exposed to the maximum allowable working pressure (MAWP), at the maximum rated temperature, for the maximum number of (design) cycles, in an outdoor weathering environment. The majority of PVHOs are not operated to such extremes, and service life may indeed be longer than design life. Conversely, if a window is not properly cared for (i.e., becomes exposed, either operationally or nonoperationally, to other detrimental factors that are not, and cannot be, factored into the design life), then the actual service life could be much shorter than the design life. Thus, the recommendation was made that design life and service life be addressed as two different subjects. In 1999 the In-Service Task Group became a PVHO subcommittee, with the most immediate task being the establishment of in-service criteria for PVHO windows and viewports.
This Standard provides the necessary in-service criteria to supplement Section 2, Viewports, of ASME PVHO-1, which applies to new construction only. By comparison, this Standard applies to all ASME PVHO-1 acrylic windows, regardless of their date of manufacture. This Standard consists of both technical criteria and guidelines. They are intended to provide guidance to the user and/or the jurisdictional authority in regard to the establishment of potential service life, and the necessary care, inspection, and repair during that service life—depending on the actual service conditions to which the PVHO and windows have been, or will be, exposed.
Finally, this Standard was prepared as a “stand-alone” document. All forms additional to those normally supplied with the window in accordance with ASME PVHO-1, which may be necessary throughout the service life of the window, are provided herein. Similarly, all necessary ASME PVHO-1 technical data applicable to service and repair (if required) are also provided in this Standard.
ASME B16.1, Pipe Flanges and Flanged Fittings
This standard is for American National Standard cast-iron pipe flanges and flanged fittings. Class 125 may be used as reference standard for the outside diameter of FRP flanges larger than 24 in. nominal pipe diameter and covers the hole sizes and number of bolts, when drilling.
ASME B16.5, Pipe Flanges and Flanged Fittings
This standard is for American National Standard steel pipe flanges and flanged fittings. Class 150 may be used as reference standard for the outside diameter of FRP flanges up to and including 24 in. nominal pipe diameter and covers the hole sizes and number of bolts, when drilling.
ASME B18.22.1, Plain Washers
This standard gives the dimensions of plain steel washers, required under bolt heads and nuts on FRP flanged joints and manholes.
ASME B31.3, Process Piping
ASME B31 Code for Pressure Piping, Section 3 covers process piping typically found in petroleum refineries, chemical, pharmaceutical, textile, paper, semiconductor, and cryogenic plants, and related processing plants and terminals. This section of the code is accepted in many parts of the world for the design of process piping. It has a chapter covering non-metallic piping and piping lined with non-metals.
Publisher: The American Society of Mechanical Engineers (ASME).www.asme.org
ASTM Standards, Section 8 – Plastics.
This section as published in 2013 includes 704 standards is divided as follows:
08.01 Plastics (I): C1147-D3159
08.02 Plastics (II): D3222-D5083
08.03 Plastics (III): D5117 – latest. Reinforced Plastic Piping Systems and Chemical Equipment; Plastic Building Products.
08.04 Plastic Piping Systems
Only a limited number of specifications in the above section are required for work undertaken on the plastics and composites designs that are normally encountered. However, there are also several test methods used on the raw materials and finished products that may be referenced. A list of selected ASTM standards are may be viewed here.
AWWA C950-13 Fiberglass Pressure Pipe
This standard covers the fabrication and testing of nominal 1 in. through 156 in. (25 mm through 4,000 mm) fiberglass pipe and joining systems for use in both above ground and below ground water systems. Service and distribution piping systems and transmission piping systems are included. Both glass-fiber-reinforced thermosetting-resin pipe (RTRP) and glass-fiber-reinforced plastic-mortar pipe (RPMP) including epoxy-resin and polyester-resin systems are covered, and commercial-grade E-type glass is specified as the glass-fiber reinforcement material in the pipe wall. Liner materials incorporated include thermosetting or thermoplastic resin, reinforced or unreinforced, with or without fillers. This standard uses American customary units, but has some conversions to SI units.
Publisher: American Water Works Association www.awwa.org
BS 4994 Design and construction of vessels and tanks in reinforced plastics
BS 4994 is a British Standard Specification published by the British Standards Institute. It has extensive methods to develop safety factors based on size, pressure, chemical and temperature conditions and cyclic variations during operation. The laminate design is based on the consideration of the various types of layers and their orientation and properties. This standard is been made obsolescent by the issue of BS EN 13121. This standard uses SI[1] units.
BS EN 13121 GRP tanks and vessels for use above ground.
The EN 13121 standard, when preceded by BS, has the status of a British Standard. This standard is divided into four parts:
BS EN 13121-1 Part 1: Raw Materials – Specification conditions and acceptance conditions,
BS EN 13121-2 Part 2: Composite materials – Chemicals,
BS EN 13121-3 Part 3: Design and workmanship,
BS EN 13121-3 Part 4: Delivery, installation and maintenance.
The designation EN indicates that it is a European standard and has been adopted by CEN[2] (Comité Européen de Normalisation) for use by its member countries. It has been developed from BS 4994 and provides more detailed methods of determining the safety factors necessary for long-term performance. It is more comprehensive than the BS 4994 standard. From personal experience, there were some aspects that caused issues when used for design. These were cleared up by the issue of Amendment A1:2010 and the corrigendum issued May 2011. This standard uses metric units. Several other BS and EN standards applicable to tanks and both above ground and underground pipe are on file in our library. These standards use SI units. A list of related ISO and EN standards may be seen here.
Publisher: British Standards Institution, Inc. BSI
Thermoplastic Tank Fabrication Standards
DVS Technical Code DVS 2205-1 Calculation of tanks and apparatus made of thermoplastics – Characteristic values.
DVS Technical Code DVS 2205-2 Calculation of tanks and apparatus made of thermoplastics – Vertical round, non-pressurised tanks.
DVS Technical Code DVS 2205-3 Design of thermoplastic tanks and apparatus – Welded joints.
The above codes are prepared and issued by the Technical Committee, Working Group “Joining of Plastics” of the DVS – DEUTSCHER VERBAND FÜR SCHWEISSEN UND VERWANDTE VERFAHREN E.V. These are the pre-eminent standards that may be applied to the design, fabrication, inspection and testing of tanks and equipment made from a variety of thermoplastics materials including, HDPE, PP, PVC. Other related DVS codes are also on file in our digital library. These codes are in SI units.
Publisher: DVS Media www.dvs-media.eu/en/
Other Standards
ASCE/SEI 7-10 Minimum Design Loads for Buildings and Other Structures
ASCE/SEI 7-10, is a complete revision of ASCE Standard 7-05. The standard is published by the American Society of Civil Engineers and the Structural Engineering Institute. It provides minimum load requirements for the design of buildings and other structures that are subject to building code requirements. It includes tanks and vessels and associated items such as piping, ducting, ladders, walkways and catwalks. This document uses both the SI (International System of Units) and United States customary units.
Publisher: American Society of Civil Engineers (ASCE), www.asce.org
AWS D1.1, Structural Welding Code — Steel
This code covers the welding requirements for any type of welded structure made from the commonly used carbon and low-alloy constructional steels.
Publisher: American Welding Society www.aws.org
UBC – Universal Building Code.
The UBC was first published in 1927 by the International Council of Building Officials, Pasadena, CA. It was intended to promote public safety and provided standardized requirements for safe construction which would not vary from city to city as had previously been the case. Updated editions of the code were published approximately every three years until 1997, which was the final version of the code. It covers snow and wind loads and has a seismic zone map for the United States and for many places located outside of the United States and describes the procedure for determining Soil Profile Types. It discusses the various factors to be applied depending on shape, height and location, with additional considerations to be applied depending on the importance of the structure or whether hazardous materials are involved. It covers loadings to be applied to walkways and catwalks.
IBC – International Building Code
The UBC was replaced in 2000 by the new IBC (International Building Code) published by the (International Code Council). The ICC was a merger of three predecessor organizations which published three different building codes. These were:
- International Council of Building Officials (ICBO) Uniform Building Code.
- Building Officials and Code Administrators International (BOCA) National Building Code.
- Southern Building Code Congress International (SBCCI) Standard Building Code.
The new ICC was intended to provide consistent standards for safe construction and eliminate differences between the three different predecessor codes and is primarily used in North America. The first edition of the new IBC – International Building Code was published in 2000 and has been updated several times with the latest edition published in 2012. However, the old UBC 1997 is still widely used around the world.
Publisher: International Code Council. www.iccsafe.org
OSHA 1910.27 Fixed ladders
This standard is issued by the United States Department of Labor, Occupational Safety and Health Administration. It is a useful reference to follow when designing ladders for tanks and towers. However, in Europe and other associated countries, there are EN and ISO standards that are in use and local standards that may be applicable.
Publisher: The United States Occupational Safety and Health Administration www.osha.gov
1. SI (Le Système international d’unités) or in English The International System of Units. This system is based on the MKS (metre–kilogram–second) system.
2. CEN (Comité Européen de Normalisation) or in English: The European Committee for Standardization. The current CEN Members are the National Standards Bodies of the 28 European Union countries, the 3 countries of the European Free Trade Association states: Iceland, Norway and Switzerland; plus the Republic of Macedonia and Turkey. The current affiliates are Albania, Armenia, Azerbaijan, Belarus, Bosnia and Herzegovina, Egypt, Georgia, Israel, Jordan, Lebanon, Libya, Moldova, Montenegro, Morocco, Serbia, Tunisia and Ukraine. The current partner standardisation bodies are from Australia, Kyrgyzstan and Mongolia.