... ,C250,D400 Custom Manhole Cover1. Product informationManhole Covers are manufactured for construction and public use. Manhole Covers shall be smooth and ... A15, B125, C250, D400, E600 and F900 b. A60005 for casting design c. Major standards designs available d. As per customers' drawings ... pipeline well; heat supplied, gas well;(4) As cover board for anti-corrosion project, open ditch; it as well as can ...