CSP Coupler

External couplers for joining corrugated steel pipe
Join & Restrain ReRolled or Non-Rerolled CSP

MarMac CSP couplers are a single unit external sealing band which creates a flexible, strong, and permanent seal around the joints of corrugated steel pipe. The coupler is constructed of cross-laminated layers of rubberized mastic, integrated mechanical compression bands, an internal woven reinforcement, and butyl underlays.

Our proprietary mastic aggressively adheres to the pipe surface, while the integrated compressions bands mechanically seal and form a permanent bond to the full circumference of the pipe walls. The internal woven polypropylene material provides increased shear and puncture resistance. The butyl rubber underlays compress beneath the compression bands and against the pipe wall, forming an infiltration and exfiltration proof seal on annular, spiral or helical corrugations. The combination of these technologies allows MarMac CSP Couplers to produce high performance, permanent joints regardless of whether the pipes are rerolled (addressed/annularized) or are non-rerolled (spiral or helical corrugations). MarMac CSP couplers also function on polymer coated CSP and have shown to be watertight under laboratory conditions on polymer coated Pipe.

MarMac CSP couplers are easy to install, cost-efficient, permanent, and readily available. Our dedicated production line and unique manufacturing system allow us to quickly ship small or large quantities of couplers for any size Corrugated Steel Pipe.


CMP CSP Coupler Graphic

All typical properties of MarMac CMP couplers are based on, and meet or exceed the material requirements of:

ASTM D 882 (Method A) ASTM D 624 (Die C) ASTM D 570 ASTM D 1682

*For sizes 30″ and larger, an additional layer of cross-laminated polyethylene is placed within the coupler.

In a laboratory setting, the coupler has been third party tested for hydrostatic pressure tolerance. The coupler was found to withstand a minimum hydrostatic pressure of 10 psi over the course of several minutes.

Couplers should be stored carefully in their original packaging, out of direct sunlight and protected from the elements. Materials should be kept away from direct heat, sparks, and open flame. For optimum results, couplers should be stored in a tepid (60°-80°) environment prior to installation.

Ash-inert matter 8% 15%
Volatiles 0.1% 2.0%
Softening temp 175°F
Specific gravity 0.95 1.05
Penetration 60 dmm 90 dmm
Flow 10 mm 10 mm
Tensile strength 4000 psi
Elongation at break 100%
Tear resistance 1500 psi
Water absorption
Tensile strength (Warp) 75 lb/in
Tensile strength (Fill) 75 lb/in
Elongation at break (Warp) 20%
Elongation at break (Fill) 20%

The coupler shall be placed around the pipe, mastic side to the pipe, spanning the joint. The protective release film shall be removed and the coupler applied with the overlap at the top of the pipe. The straps shall be secured (outside straps first) on the larger outside diameter pipe (when applicable) with the propert tools; the securing straps on the outside of the smaller outside diameter pipe shall then be secured. The inside strap shall be tightened last. The closing flap shall cover the exposed strap work area, completing the joint.


Pipe sizes 12″-144″
Hydrocarbon & UV-Resistant Versions


New Installations
Detention Systems
Polymer Coated CSP
Non-Rerolled Pipe
Rerolled Pipe

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*All statements and technical information are based on tests and/or data which MarMac Manufacturing deems reliable, however, MarMac does not warrant or guarantee the accuracy or completeness of such information. Please read further manufacturer liability and warranty information.