Composite Manhole Cover

Sewage Manhole Lids

Manhole lids, especially composite ones, are widely used in oil, gas, petrochemical, water and sewage industries, telecommunications and factories. In the wake of many problems with the use of metal manhole lids, such as breakage, rusting, rotting, recyclable materials and theft, Pars Ethylene Kish Co. in Iran, and in line with the advanced world technology, manufactured composite non-metallic manhole lids with the best quality. The popularity and desire to replace the metal manhole lids with composite ones are increasing, due to the reduction in the cost of stealing cast iron lids, the high mechanical and hydraulic resistance, chemical resistance, apparent beauty (possibility to produce in different colors), resistance to corrosive sewage gases and non-erosion. Composite manhole lids come from the combination of materials, polymer resins and other chemicals.

Advantages of composite sewage manhole lids

• Being anti-theft due the use of non-recyclable materials
• Resistance to corrosion and acidic decay
• Resistance to sunlight due to the presence of anti-UV materials
• Usability in any climate and high temperature and below zero
• ightweight, yet resistant to high pressures
• Color variation and design based on the principles of urban beautification principles
• No sound while under wheel pressure
• Leveling without displacement of the hasp
• Production based on the logo and the name of the customer
• Composite manhole lids are manufactured according to the BS-124 standard and tested according to the classes in the table
• Class: A15, B125, C250, D400
• Pressure bearing (ton): 1.5, 12.5, 25.40

Applications of composite manhole lids

• Sewage visit lid
• Fire extinguishing
• Meter lid
• Tap and line lid
• Communications lid
• Basin lid

Size of manhole lids

In accordance with the safety requirements provided in the national and international standards, the size of the lid of all manholes, including composite, cast iron and ..., must be at least 600 mm plus a 50 mm seat (25 mm in each side) and the diameter of the lid should be 650 mm. Using standard size lids are important for leveling the size of the lids in the country.

Composite manhole lid materials

The composite manhole lid materials contain reinforcing fibers (silica), encapsulated in a matrix of thermosetting resin. These materials are molded as a single integrated structure.

Requirements and tests for manhole composite lids

Composite lids must undergo various tests in accordance with pp. 52-56 of the standard as well. The tests are as follows:

• Tensile modulus and stress
• Water absorption
• Resistance to vehicle fuel
• Deflection under force
• Creep resistance
• Fatigue resistance
• Impact resistance
• Thermal stability
• Surface Resistivity
• Wear resistance
• Permanent endurance
• Power test
• UV resistance

Classification of the location of composite lids

The lids are manufactured in six different classes that are selected and used according to the lid installation location in the city (pp. 14 and 15 of the Standard - Paragraphs 4 and 5). Grouping guidance based on the lid location is as follows:

• Group 1: A15 with a tolerance of 1.5 tons for sidewalks and bike rides
• Group 2: B125 with a tolerance of 12.5 tons for sidewalks, and parking lots
• Group 3: C250 with a tolerance of 25 tons for the margin of the curbing maximum 0.5 m to the roadway and 0.2 m to the sidewalk
• Group 4: D400 with a tolerance of 40 tons for roadway and main streets
• Group 5: E600 with a tolerance of 60 tons for traffic areas and heavy vehicles, such as harbors and airports
• Group 6: F900 with a tolerance of 90 tons for heavy-duty vehicles such as airports

To ensure the required load bearing, the lids should be tested in validated laboratories under pressure tests (in accordance with Table C.1, pp. 67 and 68 of The Standard).