Manholes for external sewers

General information regarding plastic manholes, their advantages as well as the technical and economic arguments for their use are described at the beginning of the manhole chapter

Manholes are also are modular, multi-element and are recommended to be used in infrastructure, in municipal, industrial or residential and commercial networks on collectors with a diameter up to 400 mm through the use of cast iron covers and other accessories for traffic.

These types of manholes were designed to be installed to depths up to 6 m, including in areas with high level of groundwater. Reference standards: EN 13598-2; EN 14982; EN 14396; ISO 9969; EN14830.

Manholes are made through injection from PP (polypropylene) and are made out of three basic elements:

The manhole raft (base)
The manhole elevation column
The manhole cone

According to our classification the B.1. manhole subgroup contains 3 types of manholes: Pro 800, Pro 1000 and Tegra 1000NG. In this case, unlike for corrugated manholes where we relate to the exterior diameter of the corrugated elevation column, the values specified refer to the interior diameter of the manhole (column).

General information regarding plastic manholes, their advantages as well as the technical and economic arguments for their use are described at the beginning of the manhole chapter.

Single block manholes are made from one element with different heights and are recommended to be used in infrastructure, in municipal, industrial or residential and commercial networks installed on collectors with a diameter up to 500 mm through the use of cast iron covers and other accessories for traffic.

These types of manholes were designed to be installed to depths up to 4 m. Please contact us to provide you the special installation instructions for areas with high groundwater levels. Single block manholes are made from polyethylene through the process called “rotomoulding” or rotational moulding. This is a process that allows the individual rotation of the model when the polyethylene powder is introduced into two directions. Through this process can be obtained large size products with different shapes.

In order to simplify the installation of these manholes were developed telescope covers. In case of manholes, unlike for corrugated manholes where we relate to the exterior diameter of the corrugated elevation column, the values specified refer to the interior diameter of the manhole.

The manhole raft is foreseen with sockets with elastomeric gaskets in order to ensure a perfectly seal joint with the plastic sewage pipe used in the sewage networks. The elements of the modular manholes are also sealing among them with the help of gaskets. This guarantees an absolute tightness of the sewage system. Manhole tightness is tested at a pressure of 0.5 bars.

The plastic sewage manholes are foreseen with optimum flow profiles that ensure a safe water flow and eliminate the risk of water network clogging due to manhole obstruction.

Plastic manholes, like pipes, have an extremely high resistance to the abrasion and aggression of certain chemicals that can be found in wastewater (such as sulphuric acid).

Plastic manholes have all the advantages provided by this material: robustness, shape stability and flexibility. As it is well known, plastic products flexibility provides them better long-term durability than the rigid (concrete) because they have a better resistance to subsequent load charges.

All the components have a reduced weight that allows to be handled by one person (maximum 2 for large diameter manholes), which makes the installation easier and faster, without additional costs generated by other machineries.

Beside fast installation and simple handling it must be taken into consideration also the easier transport at a lower cost as well as the reduced space necessary for storage.

The estimated lifetime for this type of manholes is of 50 years, similar lifetime with the one of PVC pipes, proven in this case. All these features lead to numerous advantages for the companies that manage the sewage networks and their beneficiaries due to the savings that can be obtained as a result of:

Lack of long-term repairs costs.
Reduced maintenance costs.
Reduced water treatment costs due to the elimination of groundwater infiltrations in the sewage.
Eliminate the cost of soil pollution fines due to seepage.