AGA PPM-2006 Plastic Pipe Manual for Gas Service (Eighth Edition XR0603)《气体服务用塑料管道手册.第八版 XR0603》.pdf

1、Eighth EditionPLASTIC PIPE MANUALFOR GAS SERVICEAGA PLASTIC PIPE MANUAL FOR GAS SERVICE Catalog No. XR0603 iiDISCLAIMER AND COPYRIGHT The American Gas Associations (AGA) Operating Section provides a forum for industry experts to bring collective knowledge together to improve the state of the art in

2、the areas of operating, engineering and technological aspects of producing, gathering, transporting, storing, distributing, measuring and utilizing natural gas. Through its publications, of which this is one, the AGA provides for the exchange of information within the gas industry and scientific, tr

3、ade and governmental organizations. Each publication is prepared or sponsored by an AGA Operating Section technical committee. While AGA may administer the process, neither the AGA nor the technical committee independently tests, evaluates, or verifies the accuracy of any information or the soundnes

4、s of any judgments contained therein. The AGA disclaims liability for any personal injury, property or other damages of any nature whatsoever, whether special, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on AGA publications. The

5、 AGA makes no guaranty or warranty as to the accuracy and completeness of any information published therein. The information contained therein is provided on an “as is” basis and the AGA makes no representations or warranties including any express or implied warranty of merchantability or fitness fo

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7、 should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. The AGA has no power, nor does it undertake, to police or enforce compliance with the contents of this docume

8、nt. Nor does the AGA list, certify, test, or inspect products, designs, or installations for compliance with this document. Any certification or other statement of compliance is solely the responsibility of the certifier or maker of the statement. The AGA does not take any position with respect to t

9、he validity of any patent rights asserted in connection with any items which are mentioned in or are the subject of AGA publications, and the AGA disclaims liability for the infringement of any patent resulting from the use of or reliance on its publications. Users of these publications are expressl

10、y advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, is entirely their own responsibility. Users of this publication should consult applicable federal, state, and local laws and regulations. The AGA does not, through its publications in

11、tend to urge action that is not in compliance with applicable laws, and its publications may not be construed as doing so. Any changes in this document that are believed appropriate should be communicated to AGA by completing the last page of this report titled, “Form for Suggestions to Change AGA P

12、lastic Pipe Manual For Gas Service“ and sending it to: Operations test discontinued. (f) The Izod impact value will depend on the method of specimen molding and dimensions and can range beyond values shown. (g) Average time of burning 500 hrs, HDB lower confidence limit of 90%, and meet ASTMD2837 re

13、quirements for 50year linear substantiation PPI TR4 recognizes that higher design factor is justified. This results in a higher Hydrostatic Design Stress for water at 23C (73F). As noted above, the hydrostatic design stress classification for water is used only for the purposes of material designati

14、on and classification. Federal Regulation 49 CFR 192 limits the design stress for pipes in gas distribution service. As a result of these changes new Pipe Material Designations will be added to ASTM D2513 and the Pipe Material Designations for some current PE pipe materials will change. The followin

15、g are examples of recent changes. The Pipe Material Designation of most PE2406 pipe materials will change to PE2708 The Pipe Material Designation of PE3408 pipe materials will change to either PE3608, PE3710, or PE4710 depending on the pipe performance properties. Note that these changes are not yet

16、 incorporated in ASTM D2513 and by reference not incorporated in 49CFR192. Until such time that DOT references the newer version of ASTM D2513 that contains these material codes, the pipes will be marked with both the Pipe Material Designation of the referenced year of D2513 and the current Pipe Mat

17、erial Designation. ASTM D 2513 To provide a more useful description of PE materials ASTM D 2513 uses the standard thermoplastic material designation code which consist of the abbreviation for the type of plastic (PE) followed by a four-digit numerical code. The first two digits designate the ASTM Pi

18、pe Grade which is represented by a code that consists of the two letter abbreviation for polyethylene (PE) followed by two numbers that designate the density cell (Property 1) and the slow crack growth resistance cell (Property 5) as specified in Table 1 of ASTM D 3350. The last two digits CHAPTER I

19、 PLASTIC PIPING MATERIALS 8represent the materials maximum recommended design stress for water at 23C (73F). The stress is expressed in units of 100 psi with any decimals dropped. For example: PE 2406 is a Grade PE 24 material in accordance with D 3350 and has a maximum hydrostatic design stress (HD

20、S) for water at 23C (73F) of 630 psi. PE 3408 is a Grade PE 34 material with a maximum HDS of 800 psi. Other pipe designations referenced in ASTM D 2513 are listed in Table I-2. In 1985 PE 3306 was removed from ASTM D2513. In this material designation system the HDS is established applying a design

21、(or reduction) factor of 0.5 to the Hydrostatic Design Basis (HDB). The HDB is the categorized long-term strength and is determined in accordance with ASTM D 2837, Standard Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials. For further discussion of this subject refer to

22、 the section, Forecasting Pipe Strength. As pointed out in Chapter II, Federal Regulation 49 CFR 192 requires that for fuel gas transport the design factor to be applied on the HDB be not greater than 0.32. Therefore, the maximum HDS values for water that are part of this PE material designation sys

23、tem are greater than the maximum permitted for gas. For fuel gas the allowable HDS is only 64% of the maximum established for water service. TABLE I-2. Hydrostatic Design Basis (Strength Categories) and Hydrostatic Design Stresses (HDS) for Thermoplastic Pipe Materials for Water Services at 23 C (73

24、.4 F) Hydrostatic Design Stress (HDS) at 23 C (73.4 F)3 Material Designation Per ASTM D 25131 Hydrostatic Design Basis (HDB)2 For Water PE 2406 1250 630 PE 3408 1600 800 PA 32312 2500 1250 PVC 1120 4000 2000 PVC 1220 4000 2000 PVC 2116 3200 1600 1 The first two digits of the material designation cod

25、e the material in accordance with the applicable ASTM material specification (i.e. ASTM D 3350 for PE, D 4066 for PA, and D 1784 for PVC). The last two digits code the maximum recommended HDS for water expressed in hundreds of PSI. 2 The HDB is per ASTM D 2837. 3 The maximum HDS for water is establi

26、shed by multiplying HDB by a design factor of 0.5, whereas a design factor of 0.32 is used for fuel gas. Polyamide (PA) (a.k.a. Nylon) Polyamides are thermoplastics produced in a condensation reaction. The polymer is produced from one of three types of commercially available monomers. The monomer un

27、its are joined by amide links hence the name polyamide. The frequency or density of these amide links will determine the type of polyamide. The most common polyamides are types 6 and 66. ASTM D 4066 further classifies polyamides into group or type, class, and grade. Some polyamide materials are modi

28、fied with fillers, plasticizers, stabilizers and/or pigments. Because of the wide range of formulations for polyamides, their physical / chemical properties can also vary. In general, polyamides offer excellent chemical and temperature resistance and good mechanical strength. Polyamide 11 Polyamide

29、11 is the only polyamide currently listed in ASTM D 2513 for use in gas piping and is classified by D 4066 as PA 323. The pipe is currently pigmented yellow to conform to the American Public Works Association / Utility Location Coordination Council recommendations for the marking of gas lines. Polya

30、mide 11 is made from the monomer aminoundecanioc acid. This monomer is a derivative of castor oil. Polyamide 11 has been CHAPTER I PLASTIC PIPING MATERIALS 9commercially available since 1955. It is used extensively in both onshore and offshore gas and oil production. Polyamide 11 exhibits excellent

31、resistance to the temperature and environments found in these types of applications. Polyamide 11 has also been used for gas distribution since 1971 in Australia. Due to its excellent high temperature/pressure properties and resistance to slow crack growth, PA-11 is an excellent candidate for gas pi

32、ping applications such as bridge crossings, horizontal directional drilling (HDD), pipe bursting, feeder lines to outlying communities, steel replacement and insertion renewal of metal piping. Properties of Polyamide-11 (PA-11) Materials The properties of polyamides can vary greatly as a function of

33、 type or group. PA 11 is listed in ASTM D 2513 (since 1995). The following properties make PA 11 an excellent candidate for plastic gas distribution pipe: Low crystallinity Excellent impact strength Good flexibility Low water absorption Excellent chemical resistance Low hydrocarbon permeation Excell

34、ent mechanical strength. Heat fusibility Ability to be coiled Excellent resistance to slow crack growth (SCG) (no PENT failures through 8,000 hrs.) Excellent high temperature piping properties (has an 180F HDB) Excellent pressure bearing capabilities (73F HDB of 2,500 psi) PA-11 product requirements

35、 are described in ASTM D 2513 Annex A5. The Table I-5 represents typical properties of PA 11 based on testing of 2” IPS SDR 11 pipe. CLASSIFICATION OF POLYAMIDE MATERIALS Polyamides are specified by ASTM D 4066. This standard divides polyamides into 11 groups or types based upon the amide density of

36、 the polymer. These groups are then divided into classes based on application. The classes are finally divided into grades based on properties. PA 323 (PA-11) is currently the only polyamide material listed in ASTM D 2513 under mandatory Annex A5. PA 323 is a group 3, class 2, grade 3 polyamide. Per

37、 ASTM D 4066 this translates to a heat stabilized polyamide 11 meeting the specification for a grade 3. ASTM D 2513 echoes these requirements. ASTM D 2513 Polyamide 11 piping requirements are contained in D 2513 Annex A5 Polyamide-11 Installations Under waivers granted by the US Department of Transp

38、ortation, Polyamide-11 is now installed and in natural gas service in various parts of the US under varied pressures (60 to 200 psig), design factors of 0.32 and 0.40, and a variety of environments (wet and rocky soils, cold and hot/dry climates). CHAPTER I PLASTIC PIPING MATERIALS 10TABLE I-3. Clas

39、sification of Polyethylene Materials Property Test Method 0 1 2 3 4 5 6 7 8 1 Density, g/cm3D 1505 Unspecified 0.925 or lower 0.925 - 0.940 0.940 0.947 0.947 0.955 0.955 specify value 2 Melt index D 1238 Unspecified 1.0 1.0 to 0.4 0.4 to 0.15 0.15 A specify value 3 Flexural modulus, MPa (psi) D 790

40、Unspecified 138 (20 000)138 - 276 (20 000 to 40 000) 276 - 552 (40 000 to 80 000) 552 - 758(80 000 to 110 000)758 - 1103 (110 000 to 160 000) 1103 (160 000) specify value 4 Tensile strength at yield, MPa (psi) D 638 Unspecified 15 (2200) 15 - 18 (2200 - 2600) 18 - 21 (2600 - 3000) 21 - 24 (3000 - 35

41、00) 24 - 28 (3500 - 4000) 28 (4000) specify value 5 Slow Crack Growth Resistance I. ESCR a. Test condition (100 % Igepal.) b. Test duration, h c. Failure, max, % II. PENT (hours) Molded plaque, 80oC, 2.4 MPa Notch depth, F 1473, Table 1 D 1693 F 1473 Unspecified Unspecified A 48 50 B 24 50 C 192 20

42、C 600 20 10 30 100 500 specify value specify value 6 Hydrostatic Strength Classification I. Hydrostatic design basis, MPa (psi), (23oC) II. Minimum required strength, MPa (psi), (20C) D 2837 ISO 12162 NPRB5.52 (800) 6.89 (1000) 8.62 (1250) 11.03 (1600) 8 (1160) 10 (1450) ARefer to ASTM D3350 10.1.4.

43、1 BNPR = Not Pressure Rated The ending code letter designates the color and UV stabilizer as follows: Code Letter Color and UV Stabilizer A Natural B Colored C Black with 2% minimum carbon black D Natural with UV stabilizer E Colored with UV stabilizer CHAPTER I PLASTIC PIPING MATERIALS 11Class 2 3

44、3 4 6 4 E Density (0.926 0.940 g/cm3) Melt index (0.4 0.15) Flexural modulus (276 - 758 MPa) (40 000 - 110 000 psi) Tensile strength at yield (21 - 24 MPa) (3000 - 3500 psi) Slow Crack Growth Resistance II. PENT F 1473 100 h failure time Hydrostatic design basis at 23oC (11.03 MPa (1600 psi) Color a

45、nd UV stabilizer (colored) POLY (VINYL CHLORIDE) (PVC) Recently, ASTM D 2513 was revised to permit the use of PVC piping only for repair of existing piping. PVC became popular for both pressure and nonpressure piping because of its chemical resistance, long-term strength and high stiffness. However,

46、 PE has largely displaced it for gas distribution. PVC used for piping contains no plasticizers and minimal quantities of other additives. Such compositions are generally called rigid PVC to differentiate them from the flexible, plasticized compounds used for nonstructural uses. Additives that are u

47、sed may be lubricants, stabilizers, modifiers, and pigments; the amount and type has a major effect on performance and processability. The formulation is made to attain a balance of these two requirements. Small variations in additives can also significantly affect aging. Since extruders often do th

48、eir own compounding, widely varying aging characteristics are possible. Since ASTM classifications measure only initial short-term properties of unprocessed material, these differences may go undetected. A study was made of PVC compounds exposed to three years of outdoor exposure at three U.S.A. locations. It showed significant differences in aging of the three compounds; each had a different modifier. Similar but less marked effects were noted for laboratory-stored samples. Rigid PVC used for pressure pipe has been identified by the Type and Grade designation of the first editions of ASTM