1、 TR-3/2016 HDB/HDS/PDB/ SDB/MRS/CRS Policies Policies and Procedures for Developing Hydrostatic Design Basis (HDB), Hydrostatic Design Stresses (HDS), Pressure Design Basis (PDB), Strength Design Basis (SDB), Minimum Required Strength (MRS) Ratings, and Categorized Required Strength (CRS) for Thermo
2、plastic Piping Materials or Pipe 105 Decker Court, Suite 825, Irving, TX 75062 Phone: 469-499-1044 Fax: 469-499-1063 www.plasticpipe.org TABLE OF CONTENTS Foreword Notes to the Reader Acronyms and Definitions Summary of Changes Part A - Grades of Recommendations and Data requirements for HDB and PDB
3、 A.1 Grades of Recommendation A.2 Requirements for Grades at 73oF (23oC) A.3 Requirements for Grades at 140oF (60oC) A.4 Requirements for Grades at 180oF (82oA.5 Requirements for Grades at 200oF (93oA.6 Recommended HDB for New Materials A.7 Recommended PDB Ratings for Multilayer and Composite Pipes
4、A.8 Pressure Rating of Thermoplastic Pipes with Barrier Layers A.9 Substitution of Ingredients in Polyolefin/Aluminum/Polyolefin Composite Pipe Constructions A.10 Recommended HDB and PDB Rating Using ASTM D2992 Part B - Grades of Recommendations and Data Requirements for MRS and CRS,tB.1 Grades of R
5、ecommendation B.2 Protocol for Determination of MRS and CRS,t Part C - Grades of Recommendations and Data Requirements for SDB C.1 Grades of Recommendation C.2 Changes to Formulations C.3 Guidance to Use of SDB Part D - General Policies, Practices, and Procedures D.1 Policy on Colorant Changes for H
6、DB D.2 Policy for Determining Long-Term Strength (LTHS) by Temperature Interpolation D.3 Policy on Dependent Listings D.4 Changes Between Two Percentages of a Compounding Ingredient D.5 Measurement Variability D.6 Requirements for Molding Materials D.7 Establishing the Hydrostatic Design Stress for
7、a Material 2Part E - PVC Specific Policies, Practices and Procedures E.1 Standard Industry Practice of High Intensity Mixing of PVC Pipe Compounds E.2 Policy on Substitution of an Apparently Identical Ingredient in a PVC Composition E.3 Fulfilling Certain PPI TR-3 Requirements by Utilizing an Altern
8、ate Method of Analyzing Stress-Rupture Data for PVC E.4 Substitution of Resin in Poly (vinyl chloride) PVC Plastic Pipe Formulations E.5 Allowable Formulation Variability for PVC Pipe and Fittings Compositions E.6 Substitution of Thermal Stabilizers in PVC Pipe Compositions Part F - Polyethylene Spe
9、cific Policies, Practices and Procedures F.1 Substitution of Thermal Stabilizers in PE Plastics Pipe Compounds F.2 Variation in Amount of Stabilizer in PE Plastics Pipe Compounds F.3 Substitution of Ultraviolet Light Stabilizers in Non-Black PE Plastics Pipe Compounds F.4 Determination and Validatio
10、n of the Hydrostatic Design Basis (HDB) for Polyethylene Piping Materials F.5 Hydrostatic Design Basis Substantiation for PE Materials F.6 Policy on Establishing Equivalence of Modified PE Pipe Compositions F.7 Requirements for Polyethylene (PE) Materials to Qualify for a Higher Design Factor Part G
11、 - PEX Specific Policies, Practices and Procedures G.1 Protocol for PPI Listing of PEX Pipe in PPI TR-4 G.2 Policy on Formulation Modifications for PEX HDB Listings G.3 Policy on Establishing Equivalence of Modified PEX Pipe Compositions Part H - Chlorinated Poly (Vinyl Chloride) (CPVC) Specific Pol
12、icies, Practices and Procedures H.1 Policy for Obtaining a Hydrostatic Design Basis (HDB) for a new CPVC Compound H.2 Policy on Substitution of an Apparently Identical Ingredient in a CPVC Composition H.3 Fulfilling Certain PPI TR-3 Requirements by Utilizing an Alternate Method of Analyzing Stress-R
13、upture Data for CPVC H.4 Substitution of Resin in Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe Formulations 3H.5 Allowable Formulation Variability for CPVC Pipe and Fittings Compounds H.6 Substitution of Thermal Stabilizers in CPVC Pipe Compositions Appendices X.1 Test Data Report Requireme
14、nts X.1.1 Checklist for HSB Submissions X.1.2 Additional Information X.1.3 Release of Recommendations X.1.4 Appeals of Hydrostatic Stress Board Actions X.1.5 Confidentiality X.2 Suggested Letters for Transmitting the Information Required by Various Parts of this Report X.2.1 Letters from Owner of In
15、dependent Listing (For Part D.1.2) X.2.2 Letter from Intended Receiver of Independent Listing (For Part D.1.2) X.2.3 For Part E.4: Resin Substitution in PVC Compositions X.2.4 For TR-2/TR-4: PVC Generic Range Formulation X.3 Calculation Example to Convert PVC Compound Formulations from PHR to Weight
16、 Percent X.4 Plastics Pipe Institute Membership 4FOREWORD TR-3/2016 HDB/HDS/PDB/SDB/MRS/CRS Policies This report presents the policies and procedures used by the HSB (Hydrostatic Stress Board) of PPI (Plastics Pipe Institute, Inc.) to develop recommendations of long-term strength ratings for commerc
17、ial thermoplastic piping materials or pipe. Recommendations are published in PPI TR-4, “PPI Listing of Hydrostatic Design Basis (HDB), Pressure Design Basis (PDB), Strength Design Basis (SDB) and Minimum Required Strength MRS) Ratings for Thermoplastic Piping Materials or Pipe“, a regularly updated
18、document. PPI is a trade association dedicated to promoting the effective use of plastics piping systems. Since the early 1960s, HSB has worked as a volunteer group under PPIs auspices to issue listings and continually evaluate and update procedures for long-term strength forecasting. Listings are d
19、eveloped from stress rupture data submitted to the HSB by the manufacturer. The general method used to evaluate the data is given in ASTM D2837, “Standard Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials,“ for HDB, SDB and PDB listings, or in ISO 9080 for MRS listi
20、ngs, with additional requirements delineated in this report. Many important national and international thermoplastic piping standards, including those issued by ASTM, ISO (International Standards Organization), NSF International, AWWA (American Water Works Association), ANSI (American National Stand
21、ards Institute), ASME (American Society of Mechanical Engineers) and the API (American Petroleum Institute), reference these HSB/PPI listed long-term strength recommended ratings. This report was prepared by PPI as a service to the industry. The information in this report is offered in good faith an
22、d believed to be accurate at the time of its preparation, but is offered “as is” without any express or implied warranty, including WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Additional information may be needed in some areas, especially with regard to unusual or special app
23、lications. Consult the manufacturer or material supplier for more detailed information. PPI does not endorse the proprietary products or processes of any manufacturer, and assumes no responsibility for compliance with applicable laws and regulations. Questions, comments, and problems of interpretati
24、on should be referred to the Chairman of the HSB, Plastics Pipe Institute, 105 Decker Court, Suite 825, Irving, TX 75062. Copies of this report, as well as other publications, are available from the PPI website: www.plasticpipe.org. This report was updated March 2016. 5NOTES TO THE READER SOME RULES
25、 AND CONDITIONS 1. Processing Techniques: It is stressed that these policies and procedures are for developmentof recommended ratings for thermoplastics piping compounds or pipe based on test data fromgood quality pipes (extruded or molded) made by specific processing techniques. Theserecommended ra
26、tings may or may not be valid for products made by differing processingtechniques.2. Definitions and Acronyms: Definitions and Acronyms are shown in the next section. Theterminology of this report is in accordance with the definitions given in ASTM Standards D883,“Standard Definition of Terms Relati
27、ng to Plastics,“ and F412, “Standard Terminology Relatingto Plastic Piping Systems.3. Adjusting Recommended Ratings for Application-Specific Environments:HDB/PDB/MRS/CRS/SDB recommended ratings issued by PPI are for conditions equivalentto those under which the test data were obtained, e.g., constan
28、t pressure, temperature andspecific test environment. Various industry standards or regulations provide appropriate designfactors or design coefficients to calculate the corresponding maximum allowable operatingpressure for the piping system used in the desired application. Under some conditions, su
29、ch aspressure cycling, higher temperature, more aggressive environment, or handling and installationquality, all of which may significantly reduce pipe durability, a more conservative design factor ordesign coefficient should be chosen.4. The term maximum HDS (Hydrostatic Design Stress) refers to th
30、e maximum allowable workingcircumferential or hoop stress for a given set of end use conditions, from which is computed themaximum sustained working pressure of a plastic pipe. The HDS is determined by reducing theHDB by a design factor (DF), a multiplier less than 1.0, that takes into consideration
31、 variablesand degrees of safety involved in thermoplastics piping installation.HDS recommendations issued by PPI are maximum recommended values for conditions equivalent to those under which the test data were obtained, e.g., constant pressure, temperature and specific test environment. Maximum HDS
32、values are arrived at in this report by multiplying the HDB by a design factor of 0.50 unless otherwise stated in this report. Under some conditions, such as pressure cycling, higher temperature, or more aggressive environment, all of which may significantly reduce pipe durability, a more conservati
33、ve (i.e., smaller) design factor should be chosen. More information on design factors is given in PPI TR-9, “Recommended Design Factors for Pressure Applications of Thermoplastic Pipe Materials“. The HDB and HDS recommendations in this document are made for the 73F (23C) listings only. At higher tem
34、peratures, only the HDB is listed. Prior to calculating the HDS at temperatures above 120F (50C), the thermal and oxidative stability of these materials must be independently determined. This stability should be considered in selection of an appropriate DF. Sustained pressure testing at elevated tem
35、peratures in accordance with ASTM D1598 and evaluated per ASTM D2837 may not be sufficient to fully evaluate either the thermal or oxidative stability performance of plastic materials. It is the opinion of the HSB that our current policy is to provide listings of HDBs and HDSs at 73F and elevated te
36、mperature HDBs for water for thermoplastic piping compounds. The application of any design factor to elevated temperature HDBs is an issue that is best addressed 6in the product standards and/or codes. However, we do not see any reason to not utilize the application of a given design factor to an el
37、evated temperature HDB provided that other relevant design considerations such as, but not limited to, thermal stability, live and dead loads, notch sensitivity of the buried pipe, etc., are thoroughly considered. 5. Product Standards: An HDB/HDS/PDB/SDB/MRS/CRS recommended rating has beenshown, thr
38、ough both scientific procedures and historical experience, to be a useful indicator ofthe relative long-term strength of a thermoplastic material when tested under the conditions setout in test method ASTM D2837 or ISO 9080. The performance of a material (or a pipingproduct made with that material)
39、under actual conditions of installation and use is dependentupon a number of other factors and conditions, which are not addressed in this report. Theseother factors and conditions are properly governed by the relevant product standard. Theusefulness and adequacy of an HDB/PDB/SDB/MRS/CRS as an indi
40、cator of the strength of amaterial or pipe for use in any particular application is reflected in its incorporation in theapplicable product standard, along with other appropriate performance parameters for theproduct and its component material. The appropriateness of an HDB/PDB/SDB/MRS/CRSfor a spec
41、ific application is also determined by the decision of a private or governmental entity toadopt such a standard as part of its own requirements for the product. The term “50-yearstrength value,” as used in ASTM D2837, is a mathematical extrapolation that is useful in thecontext of developing an HDB.
42、 It does not necessarily constitute a representation that anymaterial with such a value will perform under actual use conditions for that period of time.6. Sunlight (UV) Exposure: These policies do not take into consideration the adequacy of aplastic compositions protection against sunlight exposure
43、. Manufacturers may include in plasticpipe compositions suitable ingredients for the protection of properties against possibledegradation by sunlight radiation during normal storage and use. The user should insure thatsufficient protection has been incorporated into the selected piping composition s
44、hould theapplication involve extended sunlight exposure during storage and/or use.7. Recommended Ratings are Formulation Specific: EachHDB/HDS/PDB/SDB/MRS/CRS issued by PPI is specific to that particular thermoplasticpiping material formulation, including the procedure for mixing, which is represent
45、ed by the datasubmitted to the HSB. Any changes in the mixing procedure, in the formulation, or in itsingredients, outside those permitted in TR-3 are considered to result in a new composition,which may have different long-term strength properties. The listedHDB/PDB/SDB/MRS/CRS does not apply to thi
46、s new composition, unless the changes havebeen made, or validated, in accordance with one or more of the policies presented in this report;or have been ruled upon by the HSB as acceptable based on information provided to the HSB.8. Resin Changes: An inherent assumption in the development of these po
47、licies and proceduresis that the commercial pipe resin will be of equivalent chemical and molecular composition,insofar as these parameters influence long-term strength and durability, to the resin used in thecomposition on which the original long-term data supplied to PPI were obtained. Anymodifica
48、tion of the resin composition is considered to result in a different material from the oneon which the original HDB and HDS listings were based. The Chairman of the HSB should benotified of such modifications and the applicable policy followed to maintain the listing. In thecase of a change in manuf
49、acturing location of the resin used in a listed compound, the Chairmanof the HSB should be notified and any applicable policy followed to maintain the listing. Also,7in the case of any deviation or circumstance not covered by a specific policy, a disposition will have to be made by the HSB in consultation with the manufacturer. 9. Disclaimer: While every effort has been made by the Plastics Pipe Institute to assure that these policies are sound, reasonable and prudent, PPI expressly disclaims any guarantee or warranty regarding their application. Each manufacturer who lists co
