The manhole input section which includes pan and bound and it places on the ground, called valve. Manholes valves are made by cast iron, with composite or polymer.

According to 14148 Iranian national standards organization, manhole's inlet must be at least 60cm. That is why the valve's hollow span must be at least 60cm.

Considering 2.5cm in each way in order to put the valve on the manhole, the minimum size of the manhole's valve must be 65cm. The depth of the vent should be at least 5 centimeters. According to 14976 Iranian national standards, valves are used and manufactured according to their installation place in 6 categories:

 

row

Category

Load tolerates (thousand KG)

Place of use

1

A15

1.5

Areas particularly for pedestrians and cyclists

2

B125

12.5

Pedestrians, pedestrian areas, car park areas

3

C250

25

The fringes of the street curbstone up to 0.5 m in front for the car section part and 0.2 m in the sidewalk

4

D400

40

The car section of the streets and car park areas for all types of road cars

5

E600

60

The areas which can tolerate heavy vehicles such as airports and harbors

6

F900

90

Special areas which can tolerate heavy vehicles such as airports

The designer has the responsibility to choose the valve. If there is any doubt in the valve category, the higher category should be chosen.

تصویر دریچه مهول

In recent years, the new valves generations are made in composite and polymer which has these advantages:

  • Less weight compared to cast iron valves
  • Theftproof
  • Has strength and long life
  • Resistant against corrosion and abrasion
  • Resistant against UV rays