Fusion of PE Materials using elctrofusion and butt fusion processes with procedure and performance qualification

HDPE pipe jointing techniques

1. Fusion of PE Materials Presented by : Gowthaman.S Date : 19 th September 2018

2. Agenda for Presentation :

3. Agenda for Presentation :

4. Introduction to Fusion processes

5. What is Butt Fusion?  Plastic welding process used to join two different pieces of a Thermoplastic. This process involves heating both pieces simultaneously and pressing them together. The two pieces then cool together and form a permanent bond. When done properly, the two pieces become indistinguishable from each other. Dissimilar plastics can result in improper bonding

6. What is Electrofusion?  Method of joining MDPE,HDPE and other plastic pipes using special fittings that have built-in electric heating elements which are used to weld the joint together. Electrofusion is a simple method of joining PE pipes in circumstances where butt fusion is not practicable, such as where valves, elbows, and tees must be added. Prefabricated fittings are used, incorporating an electrical heating coil which melts the plastic of both the fitting and the pipe, causing them to fuse together.

7. 7 Components of Butt Fusion Machine

8. Components of Electrofusion Machine

9. Butt Fusion Parameters Definition Drag Pressure – Minimum pressure required to move the pipe fixed in the clamp. Interfacial fusing Pressure-Pressure given by pipe on the heater plate to form the melt bead Melt Bead Size – Size of the bead formed on the heater plate. Butt fusing Pressure- Pressure given for fusion of pipes after heater plate removal. Heat Soak cycle time – time given for heating of entire thickness of the pipe with reduced or without pressure. Cool down time at butt fusing pressure range.

10. Butt Fusion Procedure Clean and fix the pipes on the clamps and calculate the drag pressure by bringing the ends together. Check for gaps between the pipes. If found use milling cutter or facing tool to make both the mating surfaces flat such that there is no visible gap. Place the heater plate at a temperature range of 200 to 230 degrees or as per manufacturer recommendation. Apply interfacial fusing pressure on heater plate till the required melt bead is formed. Allow the pipe to be heated with reduced pressure or zero pressure for heat soak cycle. Remove the heater plate and fuse the pipes with the butt fusion pressure recommended or calculated. Allow the set up to cool with the applied butt fusing pressure for recommended time and later release the pressure.

11. Electrofusion Procedure Clean the pipe surface with water to remove mud ,dirt and other contaminants prior to scrapping. Just before electrofusion scrap the pipe surface with a non smearing scrapping device up to a range of 0.25mm. If the pipe surface is still contaminated by touching or other external factors clean it with 70% isopropyl alcohol with a lint free cloth. Cut both the ends of the pipe perpendicular to its centerline and insert it fully into the center of the fitting or place the saddle and tighten the bolts such that the inner heating surface of the saddle touches the surface without gap. Now connect the fitting with the electrofusion machine using the prescribed leads. Enter the prescribed value of fusing energy voltage, fusing time and cooling period given by the manufacturer manually or by scanning the bar code. After energizing the coil ,remove the leads and allow it for the prescribed cooling time without any disturbances. Check whether the fusion indicator has popped out or not.

12. 12 Process Graph for Butt fusion process  A – Melt Bead Size P1 –Interfacial fusing Pressure on heater plate t1 –Time required for bead up with P1 P2 – Pressure During the Heat soak cycle t2-Heat Soak cycle time t3-Heater plate removal time t4-Time taken for Butt fusion Pressure built up P3-Butt fusing Pressure t5-Cool down time at butt fusion pressure t6-Cooling time in ambient temperature and Zero pressure.

13. Fusing Procedure Qualification(FPS & FPQR)

14. Fusion Procedure Specification(FPS) The fusing procedure specification specifies the “variables” (including ranges, if any) under which fusing must be performed. The fusing procedure specification shall address the applicable fusing process variables, both essential and nonessential. Each organization who qualifies their own FPS shall prepare a procedure qualification record (PQR).

15. Standard Fusion Procedure Specification(SFPS) & Manufacturer Qualified Fusing Procedure Specification(MEFPS) An SFPS is a butt- fusing procedure specification that contains acceptable polyethylene (PE) fusing variables based on standard industry practice and testing as reported in the Plastic Pipe Institute(PPI), Report TR-33, or ASTM F2620. A SFPS may be used for production fusing by organizations without further qualification. Changes. Changes in the essential variables or conditions of an SFPS beyond the limits specified in QF-221.1 or Table QF-254 shall require the qualification of an FPS. For Butt Fusion When the fusing procedure is limited to the conditions of the Hydraulic machine jointing procedure explained earlier ,procedure qualification testing is not required. If the organization deviates from the conditions of the procedure, procedure qualification testing in accordance with the code(QF 202.2) is required.(QF 221.1) For Electrofusion When the fusing procedure is limited to the conditions of the procedure explained earlier ,procedure qualification testing is not required. If the organization deviates from the conditions of the procedure, procedure qualification testing in accordance with the code(QF 202.2) is required.(QF 222.1)

16. Variables –Essential & Non Essential

17. Variables –Essential & Non Essential

18. Operator Performance Qualification

19. Fusion Operator Performance Qualification The performance qualification tests are intended to determine the ability of operators to make sound fused joints when following a qualified FPS,SFPS,MEFPS. The operators can be qualified by conducting mechanical tests as per the codes.

20. Operator Performance Qualification- Essential Variables Butt Fusion Material – Change in specification and diameter Position –Change in position Equipment -Change in equipment manufacturer Electrofusion Joint - Change for socket to saddle Material – Change in specification and diameter

21. Operators Performance Qualification-Test Coupon Butt Fusion Length – 150 to 215mm each side from center of the joint Width-6 to13 mm Electrofusion Length -76mm min. on both side of the fitting.

22. Operators Performance Qualification-Tests Butt Fusion 1.Reverse bend test. 2.Guided side bend test.(above 25mm thickness) Electrofusion 1.Electrofusion bend test (When fittings are above 300mm diameter.) 2.Crush test (When fittings are above 300mm diameter.)

23. Photos

24. Butt fusion of 250mm HDPE Tee with 200mm,160mm,110mm,75mm reducers using butt fusion machine

25. Butt fusion of 200mm HDPE Tee to 160mm reducer 200mm HDPE butt fusion jointing

26. Improper fit-up (left) of coupler to Spigot in HSC Saddle has been observed and training given for Proper fit up as in Fig.(Right)

27. Queries?? Thank you