Corfit Inspection Chamber

Corfit Inspection Chambers are made from PE (Polethylene) integral part of underground drainage system CICs are installed where multiple drainage lines are connected and allows easy and fast inspection, maintenance and removal of debris which is generated through the sewer flow. Being a single piece unit, they ensure leak-free inlet and outlet joints and also easy installation. Used in sewerage/drainage networks, they are easily accessible from ground level and need less effort to clean the chamber. Manufactured as per EN 13598-1 material known for its resistance to acids, bases and organic compounds. So they can withstand aggressive substances like sulphuric acid and hydrogen sulphide found in every sewer.

  • Where a branch pipe meets the main drainage pipe in the underground drainage system
  • Where there is a straight run of underground drain, Inspection Chambers need to be installed at specific intervals for maintenance purpose
  • Where there is a change in the drainage direction
  • Where there is a change in the gradient
  • Where there is a change in the drainage size

Single piece structure for easy installation and leak-free joints

Socket, spigot and side inlet connections with rubber sealing ring

Resistant to floating due to ribs and collar provided on external surface of riser/shaft

Abrasion resistant

Smooth inside invert surface for high hydraulic capacity

Chemical resistant

About 2° slope provided for gravity flow in Inspection Chamber base

Light weight

SIZES: 315mm & 600mm

Inspection Chambers are available in sizes 315mm & 600mm and suitable for invert depth.

  • For 600mm diameter the invert depth 1.25metre
  • For 315mm diameter the invert depth 0.75metre

315mm Inspection Chamber

600mm Inspection Chamber with closed side inlets

600mm Inspection Chamber with open side inlets

Note: Open & closed side inlet is available in 600mm. As per site requirement, the required size and side to be cut before installation.


LH & RH - 45° INLETS

Size: 600mm

RH - 45° INLET

Size: 600mm

LH - 45° INLET

Size: 600mm

LH & RH - 90° INLETS

Size: 315 & 600mm

RH - 90° INLET

Size: 600mm

LH - 90° INLET

Size: 600mm


Size: 600mm


The base of Corfit Inspection Chamber is compatible with below underground drainage pipes:

Size of Inspection Chamber Drainfit Pipes as per IS 15328 Foamfit Pipes as per IS 16098 - Part 1 Corfit Pipes as per IS 16098 - Part 2
600mm Base 110mm 110mm 100mm
160mm 160mm 150mm
200mm 200mm 200mm
315mm Base 110mm* 110mm* 100mm

It is also compatible with other underground drainage pipes available in the market as per the above mentioned standards.

Note: *For the marked sizes, adaptors will be provided.


Corfit Inspection Chambers can be equipped with Durafit Chamber Covers on top of the concrete fulcrum ring. These covers are made as per BS EN 124 standards:

  • A15 kN - 1.5 ton load
  • B125 kN - 12.5 ton load
  • C250 kN - 25 ton load
  • D400 kN - 40 ton load

Durafit Chamber Cover

  1. Ensure the trench excavation is at least 300mm wide on each side of the chamber base considering the characteristics of natural soil.
  2. Level the trench bottom and prepare bedding of minimum 100mm sand. Ensure that sand and trench base do not have sharp edges, big size stones or sand particles.
  3. Clean the chamber base socket and riser pipe. Then apply lubricants on the rubber ring.
  4. Position the chamber on the bed and connect the main trunk sewer line to chamber inlet. In case, sand bedding is low, increase the height and connect the chamber base inlet to main sewer line.
  5. Use the spirit bubble level scale for leveling the top of the chamber base.
  6. Cover the main sewer pipe 200-300mm with backfilled/sand material.
  7. The chamber is now firmly set on the main sewer line and is ready to connect laterals.
  8. Connect laterals and trunk outlet to chamber base sockets. All unused inlets, if open, should be plugged.
  9. Cut the inspection chamber with the help of a fine-toothed saw to fit into the required height.
  10. Inspection chambers are provided with ribs at a distance of 50mm for 600mm diameter and at 32mm for 315mm diameter to cut according to invert depth suitability as per site condition.
  11. Fill granular material (similar to bedding material) around the chamber.
  12. Backfilling of the trench should be carried out in successive uniform compacted layers of 200-300mm with good practice around entire circumference of the inspection chamber. Ensure backfill material from stone size of 40mm (1½”), lumps clay greater than 90mm (3”) and timber or other material that could prevent sound compaction.
  13. Prevent the compactor equipment/ backfill material from knocking with inspection chamber during compaction & backfill.
  14. It is necessary to compact the soil with the minimum Standard Proctor Density (SPD) of  90% with regular to heavy traffic.
  15. Keep backfill level 60mm/ 90mm below the top of the inspection chamber.
  16. Put the RCC/ Fulcrum concrete ring having minimum height of 85mm around the top of inspection chamber. The purpose of RCC/ Fulcrum concrete ring is to transmit the vehicle load towards the lower layers of the road, thus avoiding direct loading on the chamber.
  17. The distance between outer diameter of inspection chamber and inside of fulcrum concrete ring must be minimum 10mm on each side. This assures the weight (static load of chamber cover and vehicular load) is not transferred directly on chamber assembly.