PPI TN-34-2009 Installation Guidelines For Electrofusion Couplings 14” and Larger《14及更大电熔接头的安装指南》.pdf

1、 Installation Guidelines For Electrofusion Couplings 14” and Larger TN-34/2009 105 Decker Court, Suite 825, Irving, TX 75062 P: 469-499-1044 F: 469-499-1062 www.plasticpipe.org Foreword This report was developed and published with the technical help and financial support of the members of the PPI (P

2、lastics Pipe institute). 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 user

3、s. This report 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

4、 A PARTICULAR PURPOSE. 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 products or processes of any manufacturer. The information in this report is offered for consideration by industry members i

5、n 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 time, in response to comments and suggestions from users of the report. Please send suggestions of improvements to the

6、 address below. Information on other publications can be obtained by contacting PPI directly or visiting the web site. The Plastics Pipe Institute Phone: (469) 499-1044 http:/www.plasticpipe.org October 2009 Installation Guidelines for Electrofusion Couplings 14” and Larger A. Safety: Jobsite safety

7、 requirements should be fully understood and observed. Electrofusion fittings and equipment are not intended to be, and are not “Explosion Proof”. If used in a volatile environment, additional ignition concerns may be present and are not addressed in this document. When moisture at the fusion site i

8、s a safety concern, connect the leads to the fitting before the control unit is powered up. Take safety precautions to prevent exposure to electrical shock hazards. B. Operator Experience: Electrofusion couplings should only be installed by persons that have received training from an authorized elec

9、trofusion instructor, that have a strong working knowledge of polyethylene and heat fusion, and have qualified 14” and larger electrofusion joints through destructive testing. This document is a guide only, and should not be used in place of training by an authorized electrofusion instructor. Failur

10、e to follow all preparation steps can result in joint failure or leakage due to contamination or improper installation. Destructive tests are described in ASTM F1055-98 (2006) and can be in the form of burst tests, bend tests, peel tests and other methods useful in determining the quality of a fusio

11、n joint. (See Job Aid Appendix A for additional information). C. Pre-installation Requirements: 1. Pipe Diameter Some electrofusion manufacturers have specific dimensional requirements for pipe that is to be joined using electrofusion couplers. Verify that the pipe to be joined meets the electrofusi

12、on manufacturers requirements for optimum fusion. In the absence of specific dimensional requirements ensure that the pipe diameter is within the tolerances, at the specified temperature, of the applicable pipe standard (ASTM F714, AWWA C906, etc.). Standard tolerances are determined at 73F. Measure

13、 pipe diameter with a Pi tape (see Job Aid Appendix A) at 2” and 6” from the pipe end to determine diameter. Pipe toe-in or reduction in diameter, is a condition that occurs at the pipe end and should be checked to ensure that the pipe diameter is within tolerance at 2” from the end. Severe toe-in m

14、ay require the removal of up to one pipe diameter or 12” from the pipe end. In preparing a pipe for electrofusion the pipe OD is reduced by at least .014” by scraping the outside surface. This OD reduction should be taken into consideration when accepting pipe extruded close to the above minimum tol

15、erances. . 1. Pipe Ovality - Determine if an ovality condition exists: Measure the pipe diameter to determine the amount of out-of-roundness. if ovality exceeds 2%, re-rounding clamps must be used . 2. Pipe ends should be squarely cut to 90 5. A 4” or wider sling or strap can be used as a guide to m

16、ark the pipe for cutting (see Job Aid Appendix B). A level and protractor can be used to determine the angle of the cut. 3. Pipe alignment Pipe alignment should be inspected to ensure that no stresses are present in the assembly that might cause movement during fusion. 4. Power Source An adequate po

17、wer source is required. Ensure that power source is capable of delivering power for entire coupling fusion time without interruption (check generator for full fuel supply). Ensure that all connections are tight and clean. Loose connections can result in arcing or blown fuses. a. 110 Volt: A minimum

18、5000 watt continuous supply generator capable of delivering 115 volts to 135 volts at 45 Hz to 66 Hz to the control box. Minimum 30 amp breaker with “slow blow” or time delay fuse. 30 amp twist-lock Nema L5 receptacle. b. 220 Volt: A minimum 5000 watt continuous supply generator capable of deliverin

19、g 180 volts to 300 volts at 45 Hz to 65 Hz to the control box. Minimum 30 amp breaker with “slow blow” or time delay fuse. 15 amp twist-lock NEMA L6 receptacle. Note: Commercially available generators capable of meeting these requirements are usually in excess of 7500 watt capacity and need to be in

20、 good working order. 5. Extension Cords Typically, a single extension of up to 50 is permitted between the generator and the control box. The minimum wire gauge is 10/3 awg for extension lengths up to 50. Longer lengths may be allowed, consult the fitting and equipment manufacturer for specific reco

21、mmendations. 6. Control Box A 24 digit barcode compatible control box conforming to ISO 12716 must be used to deliver the required energy to the coupling. a. The control box must be capable of delivering 80 amperes at 40 volts output. b. The control box must be capable of reading the coupling barcod

22、e and applying the correct fusion parameters, including automatic temperature compensation, to the fitting without operator intervention. c. The control box must be capable of reading ambient temperatures at the fusion site. 7. Scraping Tools PIPE PREPARATION IS VERY CRITICAL TO THE ELECTROFUSION PR

23、OCESS. CAREFUL ATTENTION MUST BE GIVEN TO PROPER CLEANING AND SCRAPING PROCEDURES TO REMOVE CONTAMINATION AND SURFACE OXIDATION FROM THE PIPE SURFACE. a. Ensure that only mechanical type scraping tools designed specifically for electrofusion preparation are used to prepare the pipe surface. b. Do no

24、t use abrasives such as grinders, emery cloth, or sandpaper. 8. Markers Ensure that insertion depth and pipe scrape area markings are made with a non-greasy, non petroleum based, fast-drying, permanent marker or paint pen. 9. Cleaning agent / wiping cloth A clean, dry, non-dyed, lint free cloth is u

25、sed to clean pipe surfaces. 96% or higher Isopropyl alcohol without additive except water is recommended as a cleaning agent. Pre-impregnated wipes without additives may also be suitable. Denatured alcohol may contain other impurities and is not suitable for use with electrofusion. Under no circumst

26、ances should a coupling fusion be made with any liquid (water, oil, sewage, etc.) flowing through the pipe or fusion area. Fusion joint failure and possible electrical hazards could occur. The fusion zone must be clean and dry before and during fusion. 10. Weather Conditions Observe manufacturers re

27、commended minimum and maximum installation temperatures for electrofusion fittings. a. The typical installation temperature range is -4F to 120F (-20C to 49C), but can vary above and below that range depending on the manufacturer. If ambient temperatures are outside this range, consult the equipment

28、 and fitting manufacturer for a specific recommendation. b. Large diameter couplings may use a temperature specific fusion time or a pre-heat cycle prior to fusion. c. Protect the fusion site in case of inclement weather such as rain or snow. D. Installation procedure: 1. Clean pipe ends to remove d

29、irt, mud, and other debris from pipe ends. Clean water can be used for initial cleaning prior to scraping; however, the pipe surface must be clean and dry before scraping. Check pipe surface and remove any embedded debris that may cause damage to scraping tools. PIPE PREPARATION IS VERY CRITICAL TO

30、THE ELECTROFUSION PROCESS. CAREFUL ATTENTION MUST BE GIVEN TO PROPER CLEANING AND SCRAPING PROCEDURES TO REMOVE CONTAMINATION AND SURFACE OXIDATION FROM THE PIPE SURFACE. 2. Ensure that the pipe end has a square and even cut as close to 90 as possible. A sling or strap can be used as a guide for mar

31、king pipe ends for straight cutting. 3. Measure the total length of the coupler to be installed. Make a mark (with recommended marker) from the pipe end that is 1/2 the total length of the coupler. This mark is for stab depth purposes and will ensure that the pipe end is inserted to the center of th

32、e coupler. 4. When measuring for pipe ovality, the High/Low diameter difference should not exceed 2%. If required, place a re-round clamp immediately outside the stab depth mark. Do not scrape to remove high sides of oval pipe in order to relieve ovality. Measure for highest and lowest diameter poin

33、ts, use re-round clamps if necessary. Re-rounding devices are either commercially available (below left) or can be substituted by using full-encirclement-type metal rings (below right). 5. Scrape the outside of the pipe surface to remove oxidation and other contaminants. Use a mechanical type scrapi

34、ng tool designed specifically for electrofusion preparation to remove at least .014” (0.36 mm) from the pipe OD. Scrape the pipe surface until an outer layer or “skin“ has been removed to expose clean, virgin pipe material. Inspect the entire circumference of the scraped area to ensure total scrapin

35、g coverage. Do not touch the scraped surface youre your hands because it may introduce surface contamination. Scraped pipe should conform to the dimensional requirements of Table 1. Do not use abrasives such as grinders, emery cloth, or sandpaper 6. Do not touch the scraped pipe surface or the insid

36、e of the coupler as body oils and other contaminates will compromise fusion joint performance. If the surfaces become contaminated, clean thoroughly with a clean lint free towel and 96% isopropyl alcohol and allow to dry before assembling. Do not use alcohol with any additives other than water. CAUT

37、ION: DO NOT TOUCH THE FUSION SURFACES TO AVOID ALL POSSIBLE RECONTAMINATION OF THE COUPLING AND PREPARED PIPE SURFACES. 7. If coupler is to be pushed completely over one pipe end, scrape the pipe end for the entire length of the coupler to prevent contamination of the coupler by sliding over un-scra

38、ped pipe. 8. Install coupler onto the pipe ends so that the stab depth marks are aligned at the outer edges of the coupler. The pipe ends may be beveled to allow for easier insertion into the coupling. If necessary, use a rubber mallet (or metal hammer and wood blocks) to move coupler onto pipe. Re-

39、round clamps can be used as anchors for pulling couplers onto pipe with mechanical assist devices such as a hand winch. Use care not to damage internal wire or terminal pins. Leave plastic bag over coupler to prevent contamination, and debris from entering the open end. 9. Check pipe end alignment t

40、o ensure that there is no bind or stress exerted on the coupling before or during fusion and until cooling time has elapsed. Support for the pipe and coupling may be necessary to prevent stresses or sagging that may develop as heat is applied during fusion. 10. Make sure the generator is operating n

41、ormally before powering the control box. Connect the control box leads to the coupler. Make sure that all connections and lead adapter tips are properly sized and secure. 11. Scan the barcode to set the fusion time. Ensure that label information conforms to scanned data. Observe the manufacturers pr

42、ocedure for pre-heating or temperature specific fusion time. Start the fusion process. Do not leave unattended. Depending on the coupling manufacturer, some couplings have multiple barcodes that correspond to the ambient temperature, or a separate pre-heat barcode that is used prior to fusing the co

43、upling. Follow the manufacturers recommendation for scanning the proper barcode. Under no circumstances should a coupling fusion be made with any substance flowing through the pipe or fusion area. Fusion joint failure and possible electrical hazards could occur. The fusion zone should be clean and d

44、ry before and during fusion. 12. After the fusion cycle is complete, verify fusion cycle completion is normal. Check melt indicators if the coupling is so equipped. Note the cooling time and mark the time when the clamping time has elapsed on the pipe. Additional information such as fusion record ID

45、 number, control box serial number, etc. should also be recorded if required. For couplers with dual fusion zones, repeat for both ends of the coupler. If a fusion cycle fault occurs, note the error code displayed by the control box and proceed according to the manufacturers recommendation. In case

46、of power interruption, i.e. generator runs out of gas, leads are disconnected, or any other power interruption failure, consult the manufacturers instructions for re-fusion. Faults caused by any other circumstances should not be re-fused. 13. Backfill and handling can be completed after the recommen

47、ded minimum cooling time has elapsed. The recommended cooling time is displayed by the control box after the fusion cycle completes, or can be found on the coupler label. Pressure leak testing can be conducted after the recommended cooling time plus one hour has elapsed. The following are illustrati

48、ons of acceptable and unacceptable electrofusion joints: Good Fusion Acceptable Melt Out Unacceptable: Possible Causes: Pipe Ovality, Flat Spots, Undersized Pipe, and Binding Exposed Wire Unacceptable Possible Causes: Pipe Ovality, Flat Spots, Undersized Pipe, and Binding Short Stab Unacceptable Pos

49、sible Cause: Failure to Mark and Monitor Stab Depth Mis-Stab Unacceptable Possible Cause: Failure to Mark and Monitor Stab Depth Misalignment Unacceptable Possible Cause: Inadequate Clamping or Restraint During Fusion Mis-cut Unacceptable Possible Cause: Failure to cut Pipe End Perpendicular to The Axis of The Pipe Gouges and Scratched Unacceptable Possible Cause: Damage During Transportation or Handling of The Pipe Poor Scrape Unacceptable Poor Scrape Unacceptabl