Chase Associates Quick-Opening Conversion Model CM-3 Manway allows quick access through any existing bolted cover manway or large nozzle presently installed in a concrete wall or steel tank. Model CM-3 bolts up to all standard 24”, 30” and 36” ANSI 150lb and 300lb drilled flanges, replacing the heavy blind flange cover and providing Quick-Opening access for the remaining life of the tank or chest. The handwheel release operates only when the tank is empty and provides access in seconds without unbolting or use of tools. Conforms with OSHA Permit Required Confined Space Rules. Standard sizes are designed for ID or IPS Pipe from Sched 5 to Sched 80.