1、 105 Decker Court, Suite 825, Irving, TX 75062 P: 469-499-1044 F: 469-499-1063 www.plasticpipe.org Recommended Minimum Training Guidelines for PE Pipe Butt Fusion Joining Operators for Municipal and Industrial Projects TN-42 / March 2013 2 Foreword This technical note was developed and published wit
2、h the technical help and financial support of the members of the PPI (Plastics Pipe Institute, Inc). 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 indust
3、ry-wide basis to help engineers, code officials, specifying groups, and users. This technical note has been prepared by PPI as a service to the industry. The information in this note is offered in good faith and believed to be accurate at the time of its preparation, but is offered “as is” without a
4、ny express or implied warranty including WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 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 manufactu
5、rer. 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 note from time to time, in response to comments and
6、suggestions from users of this note. 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. www.plasticpipe.org March 2013 105 Decker Court, Suite 825, Irvi
7、ng, TX 75062 P: 469-499-1044 F: 469-499-1063 www.plasticpipe.org 3 PURPOSE The purpose of this document is to provide a general outline of PPIs recommended minimum guidelines for training an operator in properly and safely making good quality butt- fusion joints in PE pipe systems. This training gui
8、de is intended to recommend a consistent minimum level of fusion operator proficiency; certain installations may require additional operator training and proficiency. SCOPE Butt fusion joining of PE pipe is a relatively simple, forgiving, and dependable process. However, as with any kind of pipe ins
9、tallation, proper procedures and diligence must always be used to consistently make satisfactory joints. Fusion machine operators should demonstrate an aptitude for using mechanical equipment and be generally familiar with laying pipe. They should have a demonstrated ability to follow procedures and
10、 be conscientious in their work. The amount of time it takes to provide the specified training can vary greatly and depends on the number of individuals being trained as well as their aptitude and willingness to follow directions. However, participants shall not be considered “trained” until they ha
11、ve demonstrated proficiency on at least two test joints made under circumstances and field conditions representative or similar to those of the project. PE Pipe Sizes and SDR/DR PE pipe for use in industrial and municipal applications is produced in accordance with applicable industry standards (AST
12、M, AWWA, API). In AWWA, the pipe outside diameters (ODs) conform to the OD dimensions of iron pipe IPS, or to equivalent OD for DI pipe (DIOD). In general, pipes are manufactured and measured based on OD (outside diameter) and wall thickness. The ratio of outside diameter to minimum wall thickness d
13、efines the pipes SDR (Standard Dimension Ratio) or DR (Dimension Ratio) number. These numbers also define the pipes pressure rating at 80oF (27oC) in AWWA standards. And, because of the importance of the information these numbers convey, they are required to be included in the pipe markings specifie
14、d by the applicable industry standard. These standards require that all pipes be clearly marked at specified intervals with the following information: Name or trademark of the manufacturer Production code number to identify location and date of manufacture. Nominal pipe size IPS or DIPS SDR or DR nu
15、mber, or pressure rating, or both 4 The applicable industry standard(s) with which the pipe complies e.g. ASTM, AWWA, API or a combination of those specifications to which the pipe may have been manufactured, (e.g. ASTM F714 / AWWA C-906). Use the Pipe Size and SDR/DR to determine the proper fusion
16、pressures applicable for the fusion machine and product being joined. In the event this information is not immediately available the user is advised to consult with either the fusion equipment or pipe supplier. Links to PPI and the major equipment suppliers are listed as follows: Plastics Pipe Insti
17、tute www.plasticpipe.org Connectra Fusion Equipment http:/ McElroy Manufacturing Fusion Equipment http:/ RITMO America http:/ MACHINE QUALIFICATION The selected fusion equipment shall be capable of meeting all parameters of the job. The equipment shall have jaws or reducing inserts designed to prope
18、rly hold the size of the pipes being fused, and it shall have enough hydraulic force to reach the required fusion pressure during all fusion conditions. The fusion operator shall be thoroughly familiar with and trained on the equipment being used. Such training shall include at least the following:
19、1) Safety 2) Operators manual nonetheless its impact strength is reduced as temperatures drop into these ranges. Therefore, avoid dropping pipe in sub-freezing conditions. Also, keep in mind that butt fusion, when temperatures are below -4oF (-20oC), generally requires special provisions such as por
20、table shelters or trailers or other suitable protective measures with auxiliary heating. Here are some general guidelines to address different weather conditions: Cold Temperatures, Down to 32oF ( 0oC ): When butt fusing PE pipe under these conditions, it is recommended that a temporary wind barrier
21、 be set up around the operator and fusion equipment. It is also recommended that the pipe ends be closed off by use of end caps or other means to prevent the flow of cold air. These measures will help greatly to reduce the heat loss in the heater plate and provide for a more uniform heating cycle an
22、d improved operator efficiency. Cold Ambient Temperatures Below 32oF (0o C ): In addition to the above, the following preparations should be undertaken before fusing pipes. Pipe ends should be pre-heated using a heating blanket or warm air devices to elevate the pipe temperature to improve the heat
23、cycle starting condition. With pipe mounted in the fusion machine, an alternate method of pre-heating is to position the pipe ends within to inch of the heater plate face to allow the pipe ends to warm for 30 seconds to 2 minutes, depending on the pipe size and wall thickness. Before starting pipe f
24、usion, the operator needs to ensure that the ID of the pipe is clear of moisture possibly due to frost that is being melted during the warming operations. Notice: The use of direct application open flame devices, such as torches, for heating PE pipe is prohibited due to the lack of adequate heating
25、control and the possibility of oxidative damage to the pipe ends and even ignition of the pipe. The warming temperature should not be continuous nor exceed 120oF (49oC). Warm (Hot) Environment, 32oF (0oC) to 120oF(49oC): . Elevated temperature conditions can be mitigated by shading of the operator a
26、nd the equipment where applicable. Wind: Exposure of the fusion heater plate and pipe to wind can result in unacceptable temperature variations during butt fusion and possible joint contamination. When unfavorable wind conditions exist, the provision of a suitable shelter is required to 6 protect th
27、e pipe and the fusion heater plate to ensure more consistent work performance. Unfavorable wind conditions can also flow through the pipe bore and cause unacceptable temperature variations during the fusion process, therefore open pipe ends may require plugs or covers to prevent this condition. Addi
28、tional Considerations: PE pipe and fittings will expand and contract with changes in temperature so in such an event be prepared to make necessary adjustments. Where pipes are to be clamped in the fusion machine, make sure pipe, fitting and clamp surfaces are dry, clean and free of ice, frost, snow,
29、 dirt and other contamination. When butt fusion is done in cold weather, DO NOT INCREASE THE HEATING TOOL SURFACE TEMPERATURE to attempt to compensate. THE REQUIRED SURFACE TEMPERATURE MUST BE WITHIN THE SPECIFIED RANGE BETWEEN 400-450oF (204-232oC) with 425oF (218oC) being the target temperature. S
30、ome butt fusion equipment is operated hydraulically through the use of motor and hydraulic oils. When operating such hydraulically assisted equipment at ambient temperature extremes, read operators manuals to make necessary viscosity adjustments to aide in the equipments performance. The same holds
31、true for generators supporting the butt fusion equipment. In cold conditions, it will take longer to develop an indication of melt around the pipe circumference at fusion pressure and longer to develop the final bead size in the heat soak cycle. DO NOT apply “fusion pressure” during the heat soak cy
32、cle. When proper melt has been obtained, the pipe and heater should be separated in a rapid, snap-like motion on manually operated equipment. The melted surfaces should be inspected (looking for a smooth melted surface) then be joined immediately in one smooth motion so as to minimize cooling of the
33、 melted pipe ends. See Annex A1 Cold Weather Procedures in ASTM F2620 Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings for additional information and guidance. Pipe Handling Guidance: The jobsite pipe storage area should be relatively level and smooth. It should be large e
34、nough to allow for safe movement of the pipe and pipe handling equipment. The optimum situation is to have the pipe stored in close proximity to where the fusion equipment will be used for joining. The pipe should be placed on wooden beams or other type supports to keep it out of the dirt, mud etc.
35、Where ground is level, the pipe or bundles of pipe can be stacked as high as about 6 ft. but not more. Where the ground is not very level, pipe should not be stacked in bundles but should be placed individually next to one another. Likewise, coils of pipe should not be stacked on each other but shou
36、ld be placed individually on protective supports on the ground. Coils should be stored in such a manner as to prevent any possibility of rolling or falling over. 7 DANGER: Coils, bundles, and even individual lengths of pipe are very heavy and by falling or rolling over can result in property damage,
37、 serious injury or even death. For lifting pipe whether it be single pieces, coils or bundles it is extremely important to use only properly weight rated fabric slings capable of handling the load. DO NOT use wire rope or chains to lift or move pipe, they will damage it. Special care should be taken
38、 when cutting tie bands on coils or on bundled pipe. As mentioned earlier, falling, rolling, or springing pipe can be extremely dangerous. First, cut only the bands on the outside and work carefully to extract the pipe pieces as needed. Pipe Stands and Supports: When butt fusing lengths of pipe it i
39、s necessary that pipe support stands be used. These pipe support stands work best when they are positioned on either side of the fusion machine approximately 20 from the pipe ends. Adjust the height of the stands so that the pipes are level; this will help to reduce pipe drag. The more stands that a
40、re used the more freely the pipe(s) move into and through fusion machine. Other devices such as carts, racks etc. can be used to aide in supporting and feeding pipe into and through fusion units. Dos and Donts in Pipe Handling: DOs Make sure the pipe is secure and balanced prior to moving Store pipe
41、 on a level surface prior to use if possible Read and adhere to all published safety procedures on the subject of PE pipe handling When installing PE pipe do take into consideration that in locations that may experience large temperature swings between day and night, exposed pipe that is not restrai
42、ned will change in length due to expansion and or contraction. For the condition of a drop in temperature, the pipe contraction could affect any lateral connections installed in the line; if the line contains bell and spigot or mechanical joints with insufficient pull-out resistance, then there exis
43、ts the potential for joint separation. Exposed pipe that is anchored has a different response to the condition of a drop in temperature; namely, the generation of longitudinal loads that result in increased tensile stress. Temperature increases have the opposite and other effects. Therefore, it is v
44、ery important that the effects of thermal change be taken into account when installing pipe. For additional information on this subject the reader is referred to the PPI PE Handbook, Chapter 6 - Section 4. Once the pipe is buried and 8 compacted in the ditch, (not free floating or unrestrained) temp
45、erature change has very little effect on the pipe. Before pulling pipe, do check for its maximum allowable pulling load. The safe pulling load depends on the pipes OD its wall thickness and material grade. For the recommended safe values the user is referred to the Tables on this subject in Chapter
46、12 in the PPI PE Handbook. DONTS While PE pipe is an extremely tough material it can be scratched or gouged, therefore, it should not be pulled or dragged over sharp objects. Pipe is generally not acceptable for installation if it contains damage that exceeds about 10% of the minimum wall thickness
47、of the pipe designed for the application. For more details on this subject, the reader is referred to the PPIs PE Handbook, Chapter 2, section entitled Damage Inspections or consult with the pipe manufacturer. Ignore recommended handling and installation procedures Bury the pipe with large sharp roc
48、ks, tree roots or other rigid objects against the surface of the pipe Kink the pipe during handling or installation. Perform rough handling of a fusion joint for at least 30 minutes after it has come out of the fusion machine. Additional time may be required for pipes with wall thicknesses greater t
49、han 2 inches, especially if the prevailing ambient temperature is above 90oF. Stick the forklift forks into the side of the pipe. Stand under or anywhere close to the pipe while it is being unloaded from a truck Fuse pipe in a dust storm without a shelter (Dust can contaminate the fusion joint)(1) Fuse pipe in a rain storm without a shelter (Water can contaminate the fusion joint)(1)(1)For additio
