Corrugated Pipes

Corrugated Pipes provide great solutions to both new and existing infrastructural systems. They consist of an outer corrugated layer, designed to enhance pipe stiffness, absorb external pressure, and reduce overall weight. The inner layer however, is comprised of a smooth texture, designed to maximize flow efficiency and minimize friction. HDPE pipes have long been and continue to be the preferred choice in the USA and Europe. They are rapidly replacing more primitive systems such as GRP (fiber glass), concrete, and clay due to both their comprehensive advantages and finer performance levels.


Their applications range from serving as primary mediums for gravity flowing materials to protective barriers preventing the deformation and wreckage of vital equipment. Some of their uses include:

  • Storm, rain, and melt-water systems
  • Sewers
  • Gravity Water Mains
  • Culverts
  • Drainage
  • Sleeves
  • Cable Ducts


KAI’s HDPE gravity pipes have numerous advantages.

  • Light weight
  • Easy to install
  • Highly adaptable to existing systems
  • Resistant to corrosion and abrasion
  • Resistant to UV rays and chemicals
  • Flexible
  • High impact strength
  • Possess optimum hydraulics
  • Low running and maintenance costs
  • May be telescoped

Raw Material

KAI Gravity Pipes are comprised of premium quality virgin high density polyethylene (HDPE) material. The HDPE material is mixed with a masterbatch additive in order to provide the finished product with enhanced added characteristics such as UV protection and custom color preferences.


KAI Gravity Pipes ranging from sizes 100mm – 1200mm are referred to as Corrugated pipes. The material grade used for this selection is EMDA 6147.


KAI Gravity Pipes ranging from sizes 1400mm – 2400mm are referred to as Corrugated Spiral pipes, or simply Spiral pipes. The material grade used for this selection is EMDA 6147 or HE 3490LS.


KAI Gravity Pipes are available in sizes ranging from 100mm to 2400mm (inside Nominal Diameter) and are manufactured in accordance with the European Standard EN-13476. The ring stiffness class of these pipes is 8kN/m2 for sizes 100mm – 900mm, and 4kN/m2 for sizes 1000mm – 2400mm. Pipes ranging from sizes 100mm – 1200mm can be manufactured in both integral cuff and spigot profiles OR plain profiles . Pipes with integral cuff and spigot profiles come in nominal lengths of 6 meters.

Pipe Profiles

Pipe Sizes Ranging from 100mm – 1200mm

As the figure on the left reveals, the pipe's body is comprised of curves, or corrugations, throughout. These corrugations are essential to the design of the pipe, and hence this type of pipe is globally recognized as a corrugated pipe. The ends of corrugated pipes are the essential component in the jointing process. The end that looks similar to the body (and in some cases identical) is commonly referred to as the bell, or spigot. The end that has a chamber-like look is referred to as the cuff.

Pipe Sizes Ranging from 1400mm – 2400mm

HDPE Corrugated pipes of a relatively larger diameter (ø1400mm - ø2400mm) are manufactured in a different way, and are hence commonly referred to as HDPE Spiral Pipes.

The pipes are manufactured in a way which yields slightly tilted corrugations. The pipe’s characteristics however are near identical.

Jointing Techniques

KAI recommends jointing of the KAI Corrugated Pipes by seal and integral cuff joints OR double socket joints.

Integral Cuff Joints with Seals

Integral cuff joints have a cuff at one end and a spigot at the other end. The technique is a push-to-fit method with the seal made of a high quality EPDM, specifically designed to mold with the corrugation of the pipe’s outer surface.

Double Socket Joints

Double Socket Joints can be used with a pair of specifically designed EPDM-681-1 rubber seals to match the normal corrugations of the pipes and to provide a leak proof joint. (This method can be used for plain profile pipes OR maintenance and repair)

HDPE Corrugated Pipes for Gravity Applications

100 111 ±0.5 96 ±0.5
104 120 104
150 169 ±0.5 146 ±0.5
200 241±1 202 ±1
250 300 ±1 251±1
300 358 ±1 302 ±1
350 417 ±1 351 ±1
400 481 ±1 401 ±1
500 596 ±1 501 ±1
600 716 ±1 601 ±1
700 829 ±1 702 ±1
800 928 ±2 796 ±2
900 1076 ±2 901 ±2
1000 1151 ±2 995 ±2
1200 1365 ±2 1193 ±2

Outside Diameter will vary according to the pipe Stiffness and core tube selection

1402 ±5
1500 1500 ±5
1600 1600 ±7
1800 1800 ±7
2000 2000 ±8
2200 2200 ±10
2400 2400 ±10