How to Guide

98
Plastics Technical Manual
NOTICE: Charlotte does not recommend pipe joint compounds,
pastes or lubricants for thermoplastic pipe as the use of an
incompatible compound may result in the degradation or
failure of the plastic pipe or fittings.
Piping systems differ in chemical resistance. Pipe or fittings
may be damaged by contact with products containing
incompatible chemicals resulting in property damage.
• Verify that paints, thread sealants, lubricants, plasticized
PVC products, foam insulations, caulks, leak detectors,
insecticides, termiticides, antifreeze solutions, pipe
sleeve, firestop materials or other materials are
chemically compatible with ABS, PVC or CPVC.
• Do not use edible oils such as Crisco
®
for lubricant.
• Read and follow chemical manufacturer’s literature
before using with piping materials.
Exceeding recommended torque for threaded connections
may result in component damage, system failure and
property damage.
*TrademarkoftheE.I.DuPontCompany
Procedure for Cutting Threads in Schedule
80 Pipe
1. Cutting
The pipe must be cut square using a power saw, a miter box,
or a plastic pipe cutter. Burrs should be removed using a knife
or deburring tool.
2. Threading
Threads can be cut using either hand held or power threading
equipment. The cutting dies should be clean, sharp, and in good
condition. Special dies for cutting plastic pipe are available
and are recommended.
Whenusingahandthreader,thediesshouldhavea5°to10°
negativefrontrake.Whenusingapowerthreader,thedies
should have a 5° negative front rake and the die heads should
be self-opening. A slight chamfer to lead the dies will speed
production.However, thediesshould not be drivenathigh
speeds or with heavy pressure.
When using a hand held threader, the pipe should be held
in a pipe vise. To prevent crushing or scoring of the pipe, a
protective wrap such as emery paper, canvas, rubber, or a light
metal sleeve should be used.
Insert a tapered plug into the end of the pipe to be threaded.
This plug will provide additional support and prevent distortion
of the pipe in the threading area.
It is recommended that a water soluble machine oil, chemically
compatible with PVC and CPVC, be used during the threading
operation. Also, clearing the cuttings from the die is highly
recommended.
Do not over-thread the pipe. Consult the diagram and table
showingASTMF1498dimensionsforAmericanStandard
Taper pipe threads. Periodically check the threads with a ring
gauge to ensure that the threads are accurate. The tolerance
is±1
1
⁄2 turns.
Installation of Threaded Connections
1. Make sure the threads are clean. Charlotte Pipe
recommends Teflon* tape as a sealant for threaded
connections. Use a good quality Teontape whichhas
.4minimumdensity,.003”thick,.50%elongationand
chemically inert.
2. Wrap the Teon tape around the entire length of the
threads; start with two wraps at the end and wrapall
threadsoverlappinghalfthewidthofthetape.Wrapin
the direction of the threads on each wind.
3. Make threaded connections and hand tighten. Further
tighten approximately one turn past hand tight using a
strap wrench only. Do not use common wrenches or tools
designed for metallic pipe systems.