FiberGlass Reinforced Manhole

Our products are licensed by highest Technology which satisfactory complies with ISO 9001 and all relevant national and international standards. Raw materials have also must comprehensively be tested and pass the required material examinations for assurance of quality, reliability, mechanical Tests and so products are to meet requirement including but not limited to ASTM D3753, PREN 15383 and EN 1610.

Manholes are integral part of pipeline network which are designed to inspecting and monitoring the pipeline interior parts. Traditionally, manholes are made of materials such as bricks or concrete and more recently polyethylene manholes also have been used, however new technology of composite fiberglass reinforced polymer introduced GRP manholes. According to the released statics and our experiences, usage of fiberglass reinforced polymer manholes is sharply taking over in comparison with other materials based on the following technical and economical benefits for any project.

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To manufacture a GRP manhole, GRP pipe and plates are carved and joined together with the use of polyester glass fiber lamination. The technology used in the production process of GRP manholes guarantees that they have adequate and sufficient mechanical strength to bear both external (hoop load) and internal loads (axial loads) and are completely sealed, fully corrosion proof, have excellent durability and can be safely serviced and maintained while having monolithic body with defined composition and properties. When GRP pipe is proposed for vertical installation, the external forces in circular direction of pipe is low, then the required stiffness of pipe which a scale of resistance against ovality is shall not be high. Table No. 1 of ASTM D3753 gives adequate stiffness of vertical GRP pipes installed in different depths (applications like manhole), for instance, sufficient stiffness of pipe installing as manhole in depth of 3 to 5m is 2500 Pa. (equal to 0.72 PSI according to ASTM D2412).

Worthy to note that manholes can be designed according to every and each specific project`s specification.

Advantages of GRP manholes:

Resistance to corrosion

  • Durability of structure
  • Reliability and stability of structure
  • Minimum maintenance
  • Resistant to internal and external corrosion

Low weight

  • Flexibility in design and production
  • Cost saving in loading, transportation and unloading

Ease of installation

  • Fast and easy installation
  • No need for costly foundation
  • Minimum excavation
  • Ease of manipulation of manhole after installation such as adding new branches or pieces.

Stability through Design

  • No infiltration or ex-filtration

To be used as fluid gathering pit or fluid distributor

  • A part from inspecting pipeline other beneficial applications of GRP a manhole is that it can be used as a pit to gather fluid in a point and/or distribute fluid from a point through the network at any junction.


  • Installation and maintenance of Valves and other accessories
  • Pumping stations
  • Air release and breathing of the pipeline
  • Redirecting the flow of fluid
  • Providing access to inspect pipeline
  • Cleaning the main lines
  • Changing the flow condition of the fluid