Cherne Air-Loc manhole tester

The manhole tester is used to leak test manholes and other chambers using vacuum. The tester is clamped into the upper part of the manhole, the air is evacuated and a vacuum is built up inside the manhole. If the vacuum holds during the test period, the manhole is watertight; if it drops, this reveals leakage at joints, connections and penetrations before the manhole is put into service. The equipment is available in several sizes which together cover manholes from DN600 to DN900, and each size has its own clamping range matched to the manhole's inside diameter. Check the manhole's inside dimension before testing and choose the size whose working range corresponds to the dimension, so that the tester seals tightly against the manhole wall. The same equipment can be used again and again, for example when retesting after a leak has been repaired.