What is a double wall corrugated pipe?
Double wall corrugated pipe , polyethylene corrugated pipe, corrugated pipe, double wall pipe, are all the names of the pipe consisting of two layers of polyethylene. The inner layer is fully polished and the outer is corrugated and rippling so that this shape and geometric form results in high resistance in tolerance of all surface and subsurface pressures, including live or dead load underground. Double wall corrugated pipes are classified into three pressure classes (pressure means the pressure of exterior load) which are 16- 31.5- 64 kilonewton respectively each of which are used in a particular application in terms of type of soil surface, load pressures from surface and subsurface.
Double wall corrugated polyethylene pipes are highly resistant because of the soil volume and ring stiffness. The inner pressure of these pipes is usually 2 to 4 bars and hence they cannot be used in the networks under high pressure. In order to connect these corrugated pipes, coupler, washer or extruder welding could be used.
The lifetime of corrugated pipes is approximated to be about 50, 75 and even 100 years which depends on the raw material, conditions of production, storage and maintenance. Note that in case that the pipe has to be buried and endure the environmental conditions, there are some issues to be considered. As for corrugated pipes, the ph of the soil must be considered. The corrugated pipe made from polyethylene is being used for almost a decade due to its resilience against subsidence and deterioration, easy installation and its resistance against the movement of soil and pressure.
Technical specifications and quality of double wall corrugated pipe must be in accordance with DIN 16961-2 standard (pertaining dimensional control and ring stiffness of the pipe) and EN 13476 (other tests regarding quality control of the product).
- For branches of corrugated pipes three-way elbow and four-way plumpings are used.
- Corrugated pipes are produced in 6 meter filaments and 12 meter pipes are without coupler and washer.
- Corrugated pipes could be produced in diameters 100 to 1100 millimters.
- Corrugated pipes are incomparable with any other similar pipes due to light weight.
Applications of double wall corrugated pipes (double wall polyethylene pipes):
- Transmission of urban and rural sewages
- As sheath for riser
- As sheath electrical and fiber optic cables
- Alternative for water ditches in the villages and gardens
- Well wall
- Septic tank wall
- As half pipes for using in agricultural water ditches
- As drainage in different projects such as agricultural and construction applications.
And other important and priceless applications in which the corrugated pipes could be used. The properties of the corrugated pipes make it the best choice for urban managements and establishment of urban sewages and collection of surface waters, based on the current need, so that it is being used in most of the cities for sewage projects.
Advantages of corrugated pipes (double wall polyethylene pipes):
- Long lifetime
- Flexibility and resilience against bending.
- Lighter weight in comparison with steel, cast iron and concrete pipes
- Insatiability due to polished inner surface
- Resistance up to 50 degrees centigrade and insolvability in all organic solvents
- Resistance against corrosive materials (acids, bases, salts) and microorganisms.
- Resistance against ultra violet radiation of the sun due do usage of anti-UV materials.
- Resistance against attacks of rodents and microorganisms due to lack of nutritional value
- Easy installation and fast commissioning
- Good tolerability against load
- Easy transportations
- Resilience against severe cold or heat
- Enabling any fittings to be used
- Good hydraulic properties due to smooth inner surface
- Very goof resistance against abrasion, tolerability against traffic load
Corrugated pipes are the most commonly used pipes for collection and transmission of sewages in Iran and also other countries in the world. The international standard insists on production of corrugated pipes with mechanical resistance of 16 to 31.5 Newton per meters squared. In Iran, corrugated pipes must have a mechanical resistance of 31.5 newton per meters squared. All inspectors insist that the mechanical resistance of the corrugated pipe manufactured by any company must be equal to 31.5 newton per meters squared in the first place.
List of standards for double wall corrugated pipes:
Tests for corrugated pipes in order to obtain confirmation
- Impact test for corrugated pipe
- Apparent quality of corrugated pipe
- Marking of corrugated pipe
- Minimum thickness of outer layer of double wall corrugated pipe
- Minimum thickness of inner layer of double wall corrugated pipe
- Melt flow index of corrugated pipe
- Density of corrugated pipe
- Thermal stability of corrugated pipe
- Soot dispersion
- Soot volume
- Oven test for corrugated pipe raw material
- Nominal ring stiffness of double wall corrugated pipe
- Long term ring stiffness of double wall corrugated pipe
- Flexibility of corrugated pipe
Nowadays we see double wall double wall corrugated pipes in our world and daily life in the streets and alleys with a yellow or blue inside and black cross section.