The first and only manufacturer of composite manhole valves (non-recycled) from size 200 to 1000 mm with a load of BMC 5.1 to 40 tons in the first and only manufacturer of composite manhole valves (non-recycled) from size 200 to 1000 mm with load-based BMC 5.1 to 40 tonnes in the first and only manufacturer of composite manhole valves (non-recycled) from size 200 to 1000 mm with a load of 5.1 to 40 tons in BMC