CPP Coupler Systems
CPP offers different types of coupling systems to fit
a variety of site
Soil Resistant Split Coupler –
is a Clam Shell type coupler used in Non-Water Tight applications.
They are used on perforated or solid style CPP pipes at sites where
the native soil is stiff and cohesive enough to reduce the possibility
of a loose soil infiltration into the pipe that could create
a flow restriction.
Silt Resistant Spilt Coupler –
are Clam Shell type couplers to which a gasket material has been
added for the purpose of restricting Silt infiltration into the pipe
at a coupling joint. This non-water tight gasket material meets ASTM-D-1056,
Grade 2A2 or ASTM-F-477. The installer should take care to remove
all dirt and foreign matter from the pipe ends and gasket material
to insure a secure fit.
Gravity Flow –
several types of Gravity Flow couplers to impede or prevent the infiltration
or exfiltration of liquids in Non-Pressure applications.
Bell & Spigot Couplers with “O” Ring
Gaskets – These
couplers are produced on the pipe during the pipe extrusion process.
Bell & Spigot
pipes are available in 20-foot lengths. Each coupler Spigot End
comes with a non-pressure pipe water leak restriction gasket
manufactured per ASTM-D-477. Should gravity flow pressure
tests be required per ASTM-F-1417, one should not test until
the pipes have been backfilled or restrained for safety.
As with concrete, metal and clay pipes or Catch Basin/Manhole structure joint
connection work, the pipe installer must take extra installation precautions
as all coupling sites have historically been a Sinkhole formation problem, no
matter the pipes raw material base. At any coupling junction Extra Installer careshould
be taken to insure that the uniform 95% Proctor Density compacted soil
support is available totally around the pipe’s joint per plastic
pipe installation specifications ASTM-D-2321 and PPI-CPPA-100.
For Bell & Spigot couplers, the correct 95% Proctor
Density soil compaction prevents deflection stress on CPP pipe from exceeding
5%. Proper compaction thus protects couplers from an over deflection induced
pipe misalignment on the coupler “O” Ring seal as well. The bedding
under the pipe should also reach a 95% Proctor Density compacted level to prevent
reverse grades that could bend the pipe at the joint. Any reverse grades or
poorly compacted side fill related misalignment that results in bending/snaking/pinching
the pipe joint beyond 1.5 degrees will prevent a secure seal. Such can take
place in soils that experience post installation, uncontrolled moisture levels.
If CPP pipes are installed in soils that are expected to experience any movement
from a future high water table or soil-moisture ratio change, a Gravel
Pack Loadbearing Envelope, encased in a Filter Wrap,
should be used. Soils not reinforced properly to withstand soil-moisture changes,
can increase a pipes deflection to the point of jeopardizing a joint leak resistant
gasket seal. This is particularly true in non-cohesive silts, Class IV and Class
V soils. It should be noted here that the flexibility of CPP pipes is an attribute
that accommodates minor post installation soil settling and shifting, and thus
prevents many catastrophic joint misalignments often experienced by more rigid
pipe systems. The 20-foot sections of CPP pipes also reduce joint failure opportunities,
because there are fewer joints. However, in Class IV, V or fluxing Water-Table
soils, soil reinforcement practices (as noted in ASTM-D-2321) must be selected
to assure performance as would be the installation practice with rigid pipe products.
Under these site conditions, a CPP Mastic Wrap Coupler should
be specified by the engineer to avoid leakage and future possible Sinkhole formations.
When using the CPP Bell & Spigot Gasket coupler system, both the “O” Ring
and the Bell Coupler ends must be lubricated with a Non-Petroleum, Biodegradable
pipe joint lubricant. First the Protective Wrap should be removed from the
Gasket. Both the Male Spigot and the Female Bell ends should be cleaned prior
to lubrication to insure a secure seal. As corrugations can drag loose trench
soil in the coupling joint area, a clean plastic sheet of film should be placed
under the coupling joint work zone. The Bell End should cover two full pipe
corrugations on the Spigot End when fully seated.
Soil Tight Split Coupler
Silt Tight Split Coupler w/Gasket
CPP Uni-Seal TM With “O” Ring
For Silt Resistant Protection
CPP Twin-Seal TM Coupler With
Two “O” Rings
For Leak Resistance
CPP Shear Gasket Gravity Flow Seal Couplers – These
pliable couplers with stainless steel Clamp-Grip Compression
bands have been used for years connecting clay, concrete, steel and
plastic pipes in all types of environments. They are impervious to
normal sewer gases, chemicals, fungus growth and all other associated
in- ground hazards. Although, not technically correct, many CPP customers
refer to this coupler as the radiator-hose style coupler because
of the compression grip that the stainless steel bands provide.
As with any coupler, before applying, insure that no foreign matter
jeopardizes contact between the two surfaces. These couplers
impede leakage on 10” and smaller
pipes. Minor leaks maybe experienced on full flow surges. For
larger size pipes the CPP
Mastic Wrap coupler is recommended.
Shear Gasket Gravity
Water Resistant Couplers
Reducer Adapter Shear
Loosen Stainless Steel
clean surfaces prior to
Slip the coupler over the ends
to be joined, and
Mastic Wrap Coupler – This coupler
offers non-pressure, water leak resistant pipe connections for gravity
flow sewers and storm culvert CPP pipe systems. Geotechnical Engineers
should consider the use of these couplers in Class IV and V soil
types as a precautionary measure against some future sink hole formation
possibility due to soil-water migration. They are also required for
continuous water flow.
CPP wrap around style mastic couplers have an outer layer of cross-laminated
polyethylene plastic and an under layer adhesive surface of rubberized mastic
material. In between these two surface layers is a high strength shear and puncture
resistant layer of woven polypropylene. This center third layer provides toughness
against puncture as well as stretch resistance under earth load shifts of settlements.
Mastic wrap couplers from CPP are mechanically sealed by stainless steel screw
type hose clamp compression bands. These adjustable compression clamp bands are
easily secured using simple tools such as screwdrivers, nut drivers, or socket
wrenches. Proper tension on these bands will provide a seal against infiltration
and exfiltration in gravity flow, non-pressure pipes. Hose clamp compression
seals are used on sizes twelve inch and larger while metal twist style compression
ties are used on four inch through ten inch size pipes (see photo w/twist ties
Each mastic coupler comes with three hose clamp compression bands or ties located
within the coupler. There is one compression strap located in the butt joint
corrugation pipe valley, and one strap in the first valley on each side of the
butt joint. Proper compression tension on each strap (centered over a corrugation
valley) will forcibly apply the mastic surface around the corrugation crests
and walls to provide a seal. Enough tension should be applied to substantially
sink the compression straps into the corrugation valleys below the corrugation
crests in order to have a leak resistant seal. Prior to applying the mastic side
to the pipe be sure to clean the pipe of soil/dust particles that could interfere
with the mastic seal making contact with the pipe surface. CPP mastic couplers
can also be used to couple corrugated pipes manufactured with different corrugation
designs of the same pipe size as well as to couple CPP pipes to other pipes made
from a different raw material base.
To Apply the CPP Mastic Wrap Coupler
Clean the CPP pipe exterior to remove foreign
matter that could interfere with the contact between the
sealer and the pipe surface
Remove the protective wax paper film to expose
the rubberized mastic surface, and position the pipe on the
mastic so the three compression bands will be centered over
a pipe corrugation valley. To avoid getting new soil on the
clean pipe or the
coupler’s mastic surface, the installer may wish to lay down a thin plastic
sheet under the area to be joined. This will provide a clean working surface
in the ditch or on the ground.
Using a screw driver, nut driver, or socket wrench
(pliers or twist tie tool on twist style), tighten the straps.
The outside straps should be tightened first.
Remove the short section of protective film from
the closing flap, and cover the exposed portions of the straps.
Photo shows an example of the Twist Tie Style Compression
used on 4”, 6”, 8” and 10” size pipes.
Crumpler Plastic Pipe, Inc.
Post Office Box 2068 / Highway 24 West
Roseboro, NC 28382
TEL: 1-800-334-5071 · 910-525-4046
FAX: 1-800-CPP-PIPE ·
General Information, Sales, & Support: firstname.lastname@example.org
Engineered Sales: email@example.com