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Joint Fabrication Procedures for CONQUEST® Flangeless Piping Systems with Polytetrafluoroethylene (PTFE) Liner You will need Acrobat Reader to view pdf. Get Acrobat Reader
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The CONQUEST flangeless joint is made by butt-welding the inner plastic liners of two sections together. The outer steel shells of both sections are then connected using a Lokring** mechanical coupling. These joints can be field-fabricated by a trained distributor or by the end-user. With a few weeks notice, Resistoflex technical personnel can conduct an on-site training and certification program which will teach qualified personnel how to properly fabricate CONQUEST flangeless joints. The following are detailed instructions for fabricating these flangeless joints. Please read through these instructions carefully before proceeding with fabrication.

Heater Plate Temperatures and Soak Times
Liner Type

Pipe Size

Heater Plate Temperature

Soak Time
PTFE (white) 1" - 4" 785/418 4 min.

1. Turn on the controller and input the controlling temperature set-point to 785°F. Allow approximately 45 minutes for the heater to come up to temperature.

2. Using a George Fischer or Ridgid pipe cutter, make a 3/8" cut-back on the CONQUEST plastic-lined pipe. THIS IS A CRITICAL DIMENSION. PLEASE BE SURE IT IS ACCURATE.
NOTE: Cut-backs are not necessary on fittings because they are manufactured with the liner exposed.

3. Using a cold chisel and hammer, remove the metal ring to expose the inner plastic liner. DO NOT use a screw driver. The more rigid the clamping device, the easier it will be to remove the ring.

4. Install the proper inserts in the McElroy special number 14 butt-fusion welder for your pipe size.

5. Slide the Lokring coupling on the pipe. It is important to remember to do this prior to welding the liners together because the coupling cannot be positioned from the opposite end of a fitting or MULTI-AXIS® bent spool. Vented couplings are only used with PTFE and PFA lined systems.

6. Using a household cleaner or degreaser and a clean cloth, wash the pipe to remove dirt, water, oil, or any other foreign matter from the inside, outside, and ends of the plastic liners.

7. Mount the McElroy welding unit on the pipe and tighten clamps until snug.


9. Set the length of the steel housing exposed from the inside surface of the welder pipe clamp using the set-back gauge for PTFE systems. The set-back gauge should have "PTFE" stamped on it. Now firmly tighten the clamps.

10. Position the pipe facer tool between both stub ends and draw them flush against the cutter. Square the pipe ends using the facing tool supplied with the welder.

11. Visually check the pipe ends to make sure that they are aligned with each other around the circumference for contact.

12. Measure the heater plate temperature using the temperature pyrometer. A measurement of 785°F ± 10°F is acceptable.

13. Use disposable industrial hand towels to clean your hands prior to handling the adhesive film inserts.

14. Remove the inserts carefully so as not to touch the circular contact area.

15. Hang the adhesive film inserts on the adjustment brackets. NOTE: YOU MUST INSTALL AN ADHESIVE FILM INSERT ON BOTH SIDES.

16. Using the adjustment brackets position the adhesive film inserts so that they are both centered on the pipe ends.

17. Carefully insert the heater without touching the adhesive film inserts.

18. The total heating cycle time is 4 minutes; close the welding unit and apply a considerable 20# to 25# force for 30 seconds.

19. For the remainder of the cycle time, apply a moderate 10# to 12# force using the hand and thumb technique shown here.

20. While applying the 10# to 12# force, press the excess film against the heater plate so that it sticks to the heater when removed. This will prevent "stringing" of the adhesive film when the heater is removed.

21. Additionally, while applying the 10# to 12# force, remove the adhesive film insert tabs.

22. The total welding cycle time is 5 minutes; at the end of the 4-minute heating time, quickly open the butt-welding unit and snap the heater off of the PTFE liner. Light contact should be made as quickly as possible, not to exceed 3 seconds after removing the heater. Contact force should uniformly increase to approximately 25# as the weld cools over the initial 15 to 20 seconds. You should feel the handle move slightly as the PTFE cools. NOTE 1: THE 25# FORCE SHOULD BE ACHIEVED JUST AFTER THE PTFE GEL TURNS WHITE. NOTE 2: EXCESSIVE WELD FORCES WILL CAUSE THE LINER TO BUCKLE, WHICH SIGNIFICANTLY COMPROMISES THE STRENGTH OF THE WELD. Maintain the 25# force for an additional 45 seconds.

23. Lock the tension arm into place and allow the 5-minute welding cycle time to expire.

24. Using a short PTFE liner piece, clean off the excess adhesive film from the hot plate heater.
NOTE: If PFA film residue from the area of the liner thickness remains on the heat plate, the weld should be redone, as it is likely that the PFA film was removed from the weld area. Likely cause is a contaminated heat plate surface.

25. Install the glass/PTFE adhesive tape to fill the void space above the welded liners.

26. Set a Lokring coupling on top of steel shell and center coupling groove on centerline of weld bead. Using a permanent marker, mark each end of the coupling on the pipe to show installation points. Set coupling aside.

27. Slide the Lokring coupling that is on the pipe section into position between your two installation marks. Attach a C-clamp at one end to hold coupling in position.

28. Place proper inserts into Lokring tooling for coupling size being installed.

29. With Lokring tooling jaw fully retracted, slide tooling insert into coupling groove located between coupling swage rings.

30. For 1", 1/5", and 2". Actuate hydraulic unit to engage tooling jaw and allow swage ring to move axially 1/2 to 2/3 of the distance to coupling flange in the middle of the connector.

31. For 1", 1/5", and 2". Disengage tooling and remove C-clamp. Move tooling to other side of coupling, rotate the tooling around the pipe 180°, and repeat Step 29.

32. For 1", 1/5", and 2". Disengage tooling and move it to other side of coupling. DO NOT rotate tooling.

33. Actuate the hydraulic unit to engage tooling jaw and allow swage ring to contact coupling flange.

34. For 1", 1/5", and 2". Disengage tooling. Move it to other side of coupling, rotate the tooling 180° around the pipe, and repeat Step 32.

35. For 3" and 4". Install the bottom 3" inserts, if required, and lock in place with allen head screws. Note that the 4" size does not require a bottom insert. Move the tooling into the fully retracted position.

36. For 3" and 4". Move the tooling into position beneath the coupling such that the center of the coupling is aligned on top of one of the tooling recesses. Install the top inserts by retracting the spring-loaded locking pins, slide the inserts into the frame, and releasing the pins until the inserts snap into position.

37. Actuate the hydraulic unit to install the coupling. Relocate the tooling to install the other half of the coupling.

38. For 1", 1/5", and 2". Check for proper installation of coupling. When a coupling is properly installed, trailing edge of coupling body protrudes from underneath swage rings, and swage rings butt against coupling flanges.

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