1、 Butt Fusion Joining Procedure For Field Joining of Polyamide-11 (PA-11) i Butt Fusion Joining Procedure for Field Joining of Polyamide-11 (PA-11) Pipe TR-45/2008 105 Decker Court, Suite 825; Irvine, TX 75062P: +1 (469) 499-1052F: +1 (469) 499-1063,www.plasticpipe.org Butt Fusion Joining Procedure F
2、or Field Joining of Polyamide-11 (PA-11) ii Table of Contents FOREWORD iii INTRODUCTION 4 SCOPE 4 TESTING PROGRAM 5 INTRODUCTION 5 FUSION PARAMETERS 5 TESTING PARAMETERS 6 CONCLUSIONS AND RECOMMENDATIONS 6 Other Acceptable Fusion Procedures 7 APPENDIX A Butt Fusion Joining Procedure for Field Joinin
3、g PA-11 (Polyamide-11) Pipe 8 Butt Fusion Parameters: 8 Butt Fusion Procedure: 8 Secure 8 Face 9 Align 9 Melt 9 Table 1 Approximate Melt Bead Size 10 Joining 10 Hold 10 Visual Inspection 10 APPENDIX B LETTERS OF COMPLIANCE FROM PPI MEMBER COMPANIES FOR 49 CFR 192.283 FOR PIPE INTENDED FOR GAS DISTRI
4、BUTION APPLICATIONS 16 APPENDIX C ILLUSTRATION OF A PROPERLY MADE PA-11 BUTT FUSION JOINT 17 Butt Fusion Joining Procedure For Field Joining of Polyamide-11 (PA-11) iii FOREWORD This report was developed and published with the technical help of the members of the PPI (Plastics Pipe Institute, Inc.).
5、 The members have shown their interest in quality products by assisting independent standards-making and user organizations in the development of standards, and also by developing reports on an industry-wide basis to help engineers, code officials, specifying groups, and users. The purpose of this t
6、echnical report is to provide important information available to PPI on a particular aspect of polyethylene pipe butt fusion to engineers, users, contractors, code officials, and other interested parties. More detailed information on its purpose and use is provided in the document itself. This repor
7、t has been prepared by PPI as a service of the industry. The information in this report is offered in good faith and believed to be accurate at the time of its preparation, but is offered without any warranty, expressed or implied, including WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
8、 PURPOSE. Consult the manufacturer for more detailed information about the particular joining procedures to be used with its piping products. Any reference to or testing of a particular proprietary product should not be construed as an endorsement by PPI, which does not endorse the proprietary produ
9、cts or processes of any manufacturer. The information in this report is offered for consideration by industry members in fulfilling their own compliance responsibilities. PPI assumes no responsibility for compliance with applicable laws and regulations. PPI intends to revise this report from time to
10、 time, in response to comments and suggestions from users of the report. Please send suggestions of improvements to the address below. Information on other publications can be obtained by contacting PPI directly or visiting the web site. The Plastics Pipe Institute, Inc. http:/www.plasticpipe.org Ja
11、nuary 2008Butt Fusion Joining Procedure For Field Joining of Polyamide-11 (PA-11) 4 INTRODUCTION In 1994, representatives of the U.S. DOT (Department of Transportation), Office of Pipeline Safety requested that the Plastics Pipe Institute (PPI) assist in promoting greater uniformity in the joining p
12、rocedures utilized by gas utilities in the butt fusion of polyethylene (PE) gas piping products. DOT reported that it had encountered a proliferation of similar but slightly varying joining procedures from individual PE pipe producers. The slight differences in the various procedures made it more di
13、fficult for pipeline operators to qualify persons with appropriate training and experience in the use of these procedures. It was even more difficult for DOT to enforce the joining requirements in 192.283 (Plastic pipe, qualifying joining procedures) of the C.F.R. (Code of Federal Regulations) Title
14、 49. In response to DOTs request, PPI established a task group to develop a generic butt fusion procedure for the fusion joining of polyethylene piping in the form of the published PPI TR-33. In the spirit of complying with the above request a second task group was formed to develop a butt fusion pr
15、ocedure for the joining of polyamide-11 (PA-11) piping. PA-11 piping is approved for use in piping systems under the jurisdiction of CFR Title 49 Part 192 by reference of ASTM D 2513 in 192.7. PA-11 gas piping requirements are detailed in Annex A5 of ASTM D 2513. Thus this PPI technical report provi
16、des a uniform joining procedure bringing greater consistency to this aspect of gas pipeline installation, facilitate the pipeline operators efforts to qualify the procedure, reduce costs, and simplify DOTs enforcement duties. SCOPE The program undertaken by the PPI Task Group for the testing of repr
17、esentative materials under a set of conditions was designed to reflect the fusion conditions recommended for the butt fusion of PA-11 piping. Butt fusion evaluation work was performed starting in the mid 1990s by the Gas Research Institute1and continued at McElroy Manufacturing, Inc. and in the Arke
18、ma (formerly Atofina) R Optimization of Parameters Influencing Butt Fusion Integrity in Polyamide 11 Pipe; Presented at Natural Gas Technologies 2005: Whats New Tensile Testing of joints in accordance with ASTM D 638 at 0.2 ipm (192.283); Sustained Pressure Testing in accordance with ASTM D 1598 o 8
19、0C, 1850 psi hoop stress (14% above the hoop stress requirement in ASTM F 1733 Standard Specification for Butt Heat Fusion Polyamide (PA) Fitting for Polyamide (PA) Plastic Pipe and Tubing) All ductile pipe failures outside of fusion joint (or non failures). CONCLUSIONS AND RECOMMENDATIONS The resul
20、ts of this study indicate that there is a single fusion procedure with defined ranges of acceptable heater surface temperature, 495-505F, and interfacial pressure, 60-90 psi (4.14-6.21 bar), for fusing PA-11 piping. The results further indicate that there is a strong likelihood that the fusion proce
21、dure used in this testing (see Appendix A) could be qualified by gas pipeline operators under DOTs regulations in Part 192 for use with most of these PA-11 gas piping products. To the extent that this PPI procedure in 3T. Striplin, memo “Butt Fusion Parameters,” McElroy Manufacturing, Inc., (1995).
22、Butt Fusion Joining Procedure For Field Joining of Polyamide-11 (PA-11) 7 Appendix A can be qualified for use with PA-11 piping, the closer the industry can move to meeting DOTs objective of greater uniformity, efficiency, and simplicity in the area of fusion procedures. Other Acceptable Fusion Proc
23、edures It must be recognized that there are many other different procedures and fusion parameters used throughout the world that have been proven to make effective, reliable joints. The pipeline operator and every pipe producer retain the option of developing different fusion procedures for its part
24、icular products and pipelines. In certain cases, due to operating conditions, weather, or the characteristics of the joining equipment, it may be necessary or even advisable to use another procedure. PPI believes that its work in developing this procedure as a candidate for widespread acceptance thr
25、oughout the industry will lead to greater efficiency, simplicity and understanding in this area and promote the use of effective, qualified procedures for butt fusion joining of PA-11 piping. Butt Fusion Joining Procedure For Field Joining of Polyamide-11 (PA-11) 8 APPENDIX A Butt Fusion Joining Pro
26、cedure for Field Joining PA-11 (Polyamide-11) Pipe This procedure has not been qualified for use with any particular piping product or combination of piping products and must be qualified for use in accordance with 49 CFR Part 192 prior to its use to join PA-11 pipe in a gas pipeline. Any copying or
27、 reproduction of this procedure without this paragraph and the accompanying TR-XX is a violation of the copyright. This procedure is intended for butt fusion joining of PA-11 fuel gas pipe produced in accordance with ASTM D 2513. Butt Fusion Parameters: Fusion Interface Pressure Range 460-90 psi Hea
28、ter Surface Temperature Range 495 - 505F Butt Fusion Procedure: The principle of heat fusion is to heat two surfaces to a designated temperature, then fuse them together by application of a sufficient force. This force causes the melted materials to flow and mix, thereby resulting in fusion. When fu
29、sed according to the proper procedures, the joint area becomes as strong as or stronger than the pipe itself in both tensile and pressure properties. Field-site butt fusions may be made readily by trained operators using butt fusion machines that secure and precisely align the pipe ends for the fusi
30、on process. The six steps involved in making a butt fusion joint are: 1. Securely fasten the components to be joined 2. Face the pipe ends 3. Align the pipe profile 4. Melt the pipe interfaces 5. Join the two profiles together 6. Hold under pressure Secure Clean the inside and outside of the pipe to
31、 be joined by wiping with a clean lint-free cloth. Remove all foreign matter. Clamp the components in the machine. Check alignment of the ends and adjust as needed. 4Interfacial pressure is used to determine fusion joining pressure settings for hydraulic butt fusion machines when joining specific pi
32、pe diameters and DRs. Interfacial pressure is NOT the gauge pressure. Butt Fusion Joining Procedure For Field Joining of Polyamide-11 (PA-11) 9 Face The pipe ends must be faced to establish clean, parallel mating surfaces. Most, if not all, equipment manufacturers have incorporated the rotating plan
33、er block design in their facers to accomplish this goal. Facing is continued until a minimal distance exists between the fixed and movable jaws of the machine and the facer is locked firmly and squarely between the jaw bushings. Open the jaws and remove the facer. Remove any pipe chips from the faci
34、ng operation and any foreign matter with a clean, lint-free cotton cloth. Bring the pipe ends together with minimal force and inspect the face off. A visual inspection of this operation should verify square faces, perpendicular to the pipe centerline on each pipe end and with no detectable gap. Alig
35、n The pipe profiles must be rounded and aligned with each other to minimize mismatch (high-low) of the pipe walls. This can be accomplished by tightening clamping jaws until the outside diameters of the pipe ends match. The jaws must not be loosened or the pipe may slip during fusion. Re-face the pi
36、pe ends and remove any chips from re-facing operation with a clean, lint-free cotton cloth. Melt Heating tools that simultaneously heat both pipe ends are used to accomplish this operation. These heating tools are normally furnished with thermometers to measure internal heater temperature so the ope
37、rator can monitor the temperature before each joint is made. However, the thermometer can be used only as a general indicator because there is some heat loss from internal to external surfaces, depending on factors such as ambient temperatures and wind conditions. A pyrometer or other surface temper
38、ature-measuring device should be used before the first joint of the day and periodically throughout the day to insure proper temperature of the heating tool face that contacts the pipe or fitting ends. Additionally, heating tools are usually equipped with suspension and alignment guides that center
39、them on the pipe ends. The heater faces that come into contact with the pipe should be clean, oil-free and coated with a permanent nonstick coating as recommended by the manufacturer to prevent molten plastic from sticking to the heater surfaces. Remaining molten plastic can interfere with fusion qu
40、ality and must be removed according to the tool manufacturers instructions. Never use chemical cleaners or solvents to clean heating tool surfaces. The surface temperatures must be in the temperature range 495-505F. Install the heater in the butt fusion machine and bring the pipe ends into full cont
41、act with the heater. To ensure that full and proper contact is made between the pipe ends and the heater, the initial contact should be under moderate pressure. After holding the pressure very briefly, it should be released without breaking contact. On larger pipe sizes, initial pressure may be main
42、tained until a slight melt is observed around the circumference of the pipe before releasing pressure. Continue to hold the components in contact with each other, without force, while a bead of molten polyamide-11 develops between the heater and the pipe ends. Butt Fusion Joining Procedure For Field
43、 Joining of Polyamide-11 (PA-11) 10 When the proper bead size is formed against the heater surfaces all around the pipe or fitting ends, remove the heater. Melt bead size is dependent on pipe size. See Table 1 for approximate bead sizes. Table 1 Approximate Melt Bead Size Pipe Size Approximate Melt
44、Bead Size 1 ” and smaller (40mm and smaller) 1/32” 1/16” (1-2mm) Above 1 ” through 3” (above 40mm-90mm) About 1/16” (2mm) Above 3” through 8” (above 90mm-225mm) 1/8”-3/16” (3-5mm) Above 8” through 12” (above 225mm-315mm) 3/16”-1/4” (5-6mm) Joining After the heater tool is removed, quickly inspect th
45、e pipe ends (NOTE: If a concave melt surface is observed, unacceptable pressure during heating has occurred and the joint will be low quality. Do not continue. Allow the component ends to cool completely, and restart at the beginning. Except for a very brief time to seat the components fully against
46、 the heater tool, do not apply pressure during heating.), then immediately bring the molten pipe ends together with sufficient fusion force to form a bead against the pipe wall. For larger manual and hydraulic butt fusion machines, fusion force is determined by multiplying the interfacial pressure,
47、60-90 psi, by the pipe area. For manually operated fusion machines, a torque wrench may be used to apply the proper force. For hydraulically operated fusion machines, the fusion force can be divided by the total effective piston area of the carriage cylinders to give a hydraulic gauge reading in psi
48、. The gauge reading is theoretical; internal and external drags are added to this figure to obtain the actual fusion pressure required by the machine. The hydraulic gauge reading is dependent upon pipe diameter, DR and machine design. Interfacial pressure and gauge reading are not the same value. Ho
49、ld Hold the molten joint immobile under fusion force until the joint has cooled adequately to develop strength. Allowing proper cooling time under fusion force prior to removal from the clamps of the machine is important in achieving joint integrity. The fusion force should be held between the pipe ends until the surface of the melt bead is cool to the touch. Avoid pulling, installation or rough handling for an additional 30 minutes. Visual Inspection Visually inspect and compare the joint against the manufacturers recommended appearance guidelines. Visua
