General | FAQ | Cements Members
and PVC plastic pipes are primarily
joined by solvent cementing, but mechanical joints are also available.
PE, and PEX pipe cannot be joined with solvent cements.
Solvent cement joining always involves
a pipe or tube end and fitting socket or pipe bell. The inside of the
socket is slightly tapered, from a diameter slightly larger than the
pipe OD at the entry, to a dimension at the base of the socket that
is a few thousandths of an inch smaller than the pipe OD. Thus, the
pipe-to-socket match-up results in an interference fit more-or-less
midway in the socket.
Solvent cement is applied to the outside
of the pipe end and the inside of the socket. The pipe is then pushed
into the socket until it bottoms. Some codes require a primer to be
applied before the solvent cement.
Pipe and fittings are bonded together
by means of chemical fusion. Solvents contained in primer and cement
soften and dissolve the surfaces to be joined. Once the pipe and fitting
are assembled, a chemical weld occurs. This weld strengthens over time
as the solvents evaporate.
See ASTM F402 for safe handling of solvent
cements, ASTM D2855 for PVC instructions, ASTM F493 for CPVC instructions,
ASTM D2235 for ABS instructions, or the cement manufacturer's instructions
printed on the container label for further information.
Steps for Solvent Cementing with a
SAFE HANDLING PROCEDURES
- Assemble proper materials for job
(proper cement, primer, and applicator for the size of piping system
to be assembled).
- Pipe must be cut as square as possible.
Use a hand saw and miter box or mechanical saw. (A diagonal cut reduces
bonding area in the most effective part of the joint).
- Plastic tubing cutters may also be
used for cutting plastic pipe; however, some produce a raised bead
at the end of the pipe. This bead must be removed with a file or reamer,
as it will wipe the cement away when pipe is inserted into the fitting.
- Remove all burrs from both the inside
and outside of the pipe with a knife, file or reamer. Burrs can scrape
channels into pre-softened surfaces or create hang-ups inside surface
- Remove dirt, grease and moisture. A
thorough wipe with a clean dry rag is usually sufficient. (Moisture
will retard cure, and dirt of grease can prevent bonding).
- Check pipe and fittings for dry fit
before cementing. For proper interference fit, the pipe must go easily
into the fitting 1/4 to 3/4 of the way. Too tight a fit is not desirable.
You must be able to fully bottom the pipe in the socket during assembly.
If the pipe and fittings are not out of round, a satisfactory joint
can be made if there is a "net" fit, that is, the pipe bottoms in
the fitting socket with no interference, but without slop. All pipe
and fittings must conform to ASTM or other recognized standards.
- Use the right applicator for the size
of pipe or fittings being joined. The applicator size should be approximately equal
to 1/2 the pipe diameter. It is important that a satisfactory size
applicator be used to help ensure that sufficient layers of cement
- Priming: the purpose of a primer is
to penetrate and soften the surfaces so they can fuse together. The
proper use of a primer and checking its softening effect provides
assurance that the surfaces are prepared for fusion in a wide variety
of conditions. Check the penetration or softening on a piece of scrap
before you start the installation or if the weather changes during
the day. Using a knife or other sharp object, drag the edge over the
coated surface. Proper penetration has been made if you can scratch
or scrape a few thousandths of the primed surfaces away. Because weather
conditions do affect priming and cementing action, repeated applications
to either or both surfaces may be necessary. In cold weather more
time is required for proper penetration.
- Using the correct applicator (as outlined
in step #7), aggressively work the primer into fitting socket, keeping
the surface and applicator wet until the surface has been softened.
More applications may be needed for hard surfaces and cold weather
conditions. Re-dip the applicator in primer as required. When the
surface is primed, remove any puddles of primer from socket.
- Next aggressively work the primer on
to the end of the pipe, to a point 1/2" beyond the depth of the fitting
- A second application of the primer
in the socket is recommended.
- Immediately, and while the surfaces
are still wet, apply the appropriate solvent cement.
- Cementing: (Stir the cement or shake
can before using). Using the proper size applicator for the pipe size,
aggressively work a full even layer of cement onto the pipe end equal
to the depth of the fitting socket. Do not brush it out to a thin
paint type layer, as this will dry within a few seconds.
- Aggressively work a medium layer of
cement into the fitting socket; avoid puddling cement in the socket.
On bell end pipe do not coat beyond the socket depth or allow cement
to run down into the pipe beyond the bell.
- Apply a second full, even layer of
cement on the pipe.
- Without delay, while cement is still
wet, assemble the pipe and fittings. Use sufficient force to ensure
that the pipe bottoms in the fitting socket. If possible, twist the
pipe a 1/4 turn as you insert it.
- Hold the pipe and fitting together
for approximately 30 seconds to avoid push out.
- After assembly, a joint should have
a ring or bead of cement completely around the juncture of the pipe
and fitting. If voids in this ring are present, sufficient cement
was not applied and the joint may be defective.
- Using a rag, remove the excess cement
from the pipe and fitting, including the ring or bead, as it will
needlessly soften the pipe and fitting and does not add to joint strength.
Avoid disturbing or moving joint.
- Handle newly assembled joints carefully
until initial set has taken place. Follow set and cure times before
handling or testing piping system.
and cleaners contain solvents that are classified as combustible, flammable,
or extremely flammable. Keep these products well away from all sources
of ignition, such as sparks, heat, and open flames. Containers holding
these products must be kept tightly closed, except when in use.
Threshold limits for worker exposure
during an eight-hour work day have been established for each of the
solvents used in these products. Those limits are found on the Material
Safety Data Sheets of each product. It is very important to maintain
the air concentration of these solvents below these limits. When using
these products in an area of limited ventilation, a ventilating device
such as a fan or air mover can be used to maintain a safe air concentration.
Also, an air-purifying NIOSH-recognized respirator may be used. Any
ventilating device must be selected and located so it cannot provide
a source of ignition.
The solvents in these products should
not come into contact with bare skin. Use of the applicators provided
to apply the products can minimize skin contact. However, if skin contact
cannot be avoided, protective gloves should be worn.
The solvents in these products will cause
severe irritation if they come into contact with the eyes. Proper eye
protection must be worn whenever there is any possibility that such
contact may occur.
These cements must not be ingested. Do
not eat or drink when using cements, primers, or cleaners.