The special adjustment bolt facilitates the shutter
tightly fit against manhole frame and shaft.
An elastic rubber seals the shutter and avoids
bedding mortar to escape.
A sound monolithic bedding (frame and pre-cast
adjustment rings/elements) can be ensured.
• special quick adjustment bolt
• ridged galvanised steel shutter
• two or three integrated funnels for venting and filling
• shutter height approx. 210mm
• two standard sizes
• special shutters (diameter and height) on request