1,Ductile Iron Manhole Cover Description :
A manhole cover sits on metal base, with a smaller inset rim which fits the cover. The base and cover are sometimes called "castings", because they are usually made by a casting process, typically sand-casting techniques.
1.Advantages: Good compressive, bending and impact strenth,anti-corrosion, not rust, long service life 
(at least 30 years). The quality meets the same kinds cast ion manhole covers but the cost is 30% lower than. Contain no metal and no recovery value, anti-theft.
2.Applications: water supply and drainage, fire engineering, natural gas,
electricity and telecommunications, street lamp and outdoor illuminations.
2,Main Features of the Ductile Iron Manhole Cover:
 1) Consequences of temporarily overloading
Temporarily overloading may cause smash of concrete covers, seriously deformation, even slightly split. But this will not happen to FRP fiber cloth manhole cover.
 2) Safety options
There is no metal contain, directly reducing potential accident or further maintenance costs caused by thieves. Anti-slip surface offer a safe road condition even in extreme weather.
 3) Light weight
Compared with cast iron manhole cover, FRP manhole cover is 30% lighter.
Light weight allows more loading per vehicle, more convenient transportation and economical savings.
Allows a safer working condition, which single workers is enough for installation without risk of injury.
 4) Long service life
Strong resistance of acid, alkali, weathering, anti corrosion of water, dust, manhole covers used for gas are well sealed which prevent poisonous gas leaking.
Temperature tolerance is at the range of -40°C-200°C.
 3,Manhole Cover Images:

4,Manhole Cover Specifications:
1) Production information
Manhole cover are manufactured for construction and public use. Manhole cover shall be smooth and free sand holes, blow holes, distortion or any other defects
2) Material 
A) Ductile iron GGG50
B) Grey iron GG20 
3) Designs
A) EN124 Class B125 C250 D400 F 900, with different size and grammage, or as  customers' requirement.
B) as per customers' drawing or samples

4) Process
A) Molding boards
B) Hand Casting
5) Coating
A) black bitumen or epoxy .
B)Coating as per customer's requirement
6) Different accessories are available
7) Packing:
Wooden case or wood pallet, or as per customers' requirement
5，FAQ:
We have organized several common questions for our clients，may help you sincerely：
Q. Can I fit a square manhole cover into a round chamber?
A. Yes, there are a select few manhole covers which are square-to-round, meaning they will fit square or round chambers.

Q. I have a heavy traffic manhole cover but it has been broken by a forklift, why?
A. Forklifts have solid wheels which apply pressure differently to standard pneumatics and therefore covers must be specially adapted to suit this.

Q. I’ve measured my clear opening size but none of your covers match it, can you offer anything?
A. It’s likely that your cover is quite old and in imperial measurements which are no longer manufactured. However, we can offer bespoke solutions with manhole covers made to the specification you require.

Q. The project I’m working on requires a manhole cover with a quality finish, what’s available?
A. Naturally, galvanised steel of black polypropylene aren’t always ideal, and so we offer brass or stainless steel edging, as well as complete stainless steel covers.