1. To arrive at the required finished length "X", select the proper
cut-off length "D" from the cutting dimensions table for your liner
material.
NOTE: Although PP is shown, the process in steps 1-6 are identical for
PVDF. |
|
2. Cut pipe to proper cut-off length "D" using a sharp angled tip
cutter to assure an accurate cut. DO NOT USE hacksaw or wheel-type
cutters. A hacksaw tends to "lead", which produces non-right-angle
cuts. A wheel-type cutter produces a slightly beveled cut that leaves
burrs and can cause severe stress risers in the plastic liner. |
|
3. Determine the cut-back dimension "E" from the cutting dimensions
table. Using the same angled cutter, cut through the metal just to
the surface of the plastic liner at this distance "E" from the end of
the steel shell. Once the tool begins to "break through" the steel,
extra care should be taken in feeding the tool further to avoid
cutting the plastic liner. A clear indication that the cutting tool is
near the plastic is the appearance of "pick-marks" in the steel. |
4. Remove the cut steel ring from the end of the pipe by inserting
the proper size guide plug into the pipe and pulling with a modified
gear puller.
NOTE: A guide plug has two diameters. Choose the end that fits
snugly in the pipe bore. |
|
5. Cut a standard tapered pipe thread on the end of the pipe with any
conventional threader to accommodate a chamfered threaded flange.
Use standard thread length and adjust thread depth to allow flange to
be turned on hand tight until the last 1½ turns. |
|
6. Place flange on pipe with chamfer facing outward. Tighten flange
with wrench until turn-up dimension "F" between end of plastic stub
and face of flange matches requirement shown in the cutting
dimensions table. Also be sure that bolt holes on flanges at either
end of pipe spool are aligned. Flanges must be tightened with a
flange wrench and must be beyond hand tight.
Rotatable Flange Option.
Place flange and stub assembly on pipe with
chamfer facing outward. Tighten to turn-up dimension "F"
measured
from end of plastic face of stub assembly.
NOTE: Stub assembly must be beyond hand tight like the chamfered
flange. |
7. Clamp prepared pipe in horizontal or vertical position. File away
any notches on end of exposed plastic stub. File or sand away any
notches on end of exposed plastic stub. Using a clean rag and a
non-flammable degreaser that is compatible with the liner, wipe away
cutting oil, shavings and dirt from exposed plastic stub. |
|
8. With spring compressed on proper forming tool (1" - 4" or 6" - 8"
tool) attach molding die that matches pipe diameter. Fit the guide
pins in the clamping block assembly to match the flange bolt holes.
With the flaring die centered in the extended liner and the drive
screw retracted, check the guide pins fit freely in the bolt holes
with the clamping dogs behind the flange. If adjustment is needed,
loosen the adjusting nuts, center the tool and retighten the nuts.
NOTE: No compression spring is used behind the flaring die. |
|
9. Place the proper patented venting collar over the plastic stub and
place tight against the flange face, with curved crimped edge inward,
fitting into flange chamfer.
NOTE: For PTFE face, be sure to only use nickel-plated collar with
small perforated holes. DO NOT USE stainless steel collar with large
holes, which is designed for use with PVDF-lined pipe. |
|
CAUTION: When field forming, use adequate ventilation (indoors, use
exhaust fans). Avoid breathing of vapors resulting from overheating
and possible degradation of the plastic. Do not consume food or
beverages and do not smoke during fabrication process. Please refer
to the Material Safety Data Sheet before heating the material. For
more details of cautions for heating PTFE, see The Society of the
Plastics Industry (SPI) booklet on "Guide to the Safe Handling of
Fluoropolymer Resins", available from the E.I. Dupont de Nemours and
Co., Inc. (1-800-292-0181, ext.5209). Also, to prevent electrical
shock, do not use heat gun near water. |
|
10. The plastic stub can now be heated with a heat gun - attach proper
size of heat cup to the hot air gun, set the heater dials as shown
here, and allow the gun to preheat for 15-20 minutes. When gun is
ready, place gun with heat cup against the flange and heat until
most of the plastic stub becomes translucent. Let the last ¼"
at flange remain white. Heating time is 2-4 minutes. Frequently rotate
heat gun to balance heat over plastic surface. |
|
Pipe
Size |
Heat Dial Settings |
Leister
2200W
110V |
Leister
4500W
220V |
| 1" |
10 |
5-6 |
| 1 1/2" |
6-7 |
| 2" |
--- |
7 |
| 3" |
7-8 |
| 4" |
8 |
| 6" |
10 |
| 8" |
The 110V gun is only recommeded for doing pipe up through 1 1/2" dia.
|
11. Using gloved hand, gradually insert cone-shaped preformed tool
into translucent plastic stub until it reaches the flange face. Allow
plastic to cool until end lifts away from preformer before proceeding
to next step (1" - 4" sizes only). On 6" - 8", use preformer to form
plastic into trumpet shape. Allow PTFE to turn white before next step. |
|
12. With the forming die centered in plastic stub, place forming tool
guide pins into flange holes and lock clamping dogs in place. Crank
the forming die snug to flange. Use cool air or water to speed
cooling of plastic to room temperature. The remove tool.
NOTE: To assure properly flared face, it is extremely important to
cool plastic and flange to room temperature. Also, be sure to achieve
the minimum flare diameter listed here. |
|
13. Visually inspect the finished sealing face for a flat, smooth
surface and a smooth bend radius. |
14. Spark test the finished face for defects the may not be readily
visible. Adjust the sparker to arc about 1" to the flange. Insert
probe into the pipe end and circle the inside near the liner. A
defect is identified by apparent major arcing through the liner. DO
NOT USE pipe with a defective liner. |
|
15. To identify plastic liner, always be sure to attach a yellow color-coded
plastic band to the spool.
16. A ½" thick plywood cover should be bolted to the flange to
protect the plastic face and to prevent the face from "remembering"
its preformed shape and pulling away from the flange.
17. Attach proper label to plywood cover. |
