Manholes with column from smooth pipe are modular, multi-element manholes that are recommended to be used in private parking, network connections and green spaces but as well in municipal, industrial or residential and commercial networks through the use of cast iron covers and other accessories for traffic.

The maximum burying level is 6 m and the maximum level of the groundwater is 5 m. A manhole has three basic elements:

The manhole raft (base);
Manhole column;
Manhole cover.

A.1. manhole subgroup contains 3 types of manholes with elevation column from smooth PVC pipe: D200, D315, and D400mm.

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 with column from corrugated pipe are also are modular, multi-element and are recommended to be used in private parking, network connections and green spaces but as well in municipal, industrial or residential and commercial networks through the use of cast iron covers and other accessories for traffic.

The maximum burying level is 6 m and the maximum level of the groundwater is 5 m. A manhole has three basic elements:

The manhole raft (base);
Manhole column;
Manhole cover.

A.2. manhole subgroup contains 5 types of manholes with elevation column from corrugated pipe: D340, D353, D355, D670-Tegra 600 and D630-Pro630.

The “D” initial refers to the exterior diameter of the corrugated column for manhole elevation.

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.