Cherne® PROVING RING, 8 IN. 5% Deflection, SDR 35

The Cherne® Proving Ring, 8 in., 5% Deflection, SDR 35 (part #73202) is a precision go/no-go ring used to verify that an 8 in. SDR 35 deflection gauge (mandrel) is sized correctly before a deflection test. Passing the mandrel through the proving ring confirms the gauge meets the 5% deflection dimension, so test results can't be challenged over gauge size.

Key Features

• Verifies mandrel sizing — provides on-site proof that the deflection gauge is dimensionally correct for a 5% deflection spec.
• Sized for 8 in. SDR 35 pipe — matches the common PVC gravity sewer pipe standard.
• Defensible test results — documented gauge verification supports acceptance testing per ASTM D3034-based deflection specs.
• Simple and rugged — no moving parts; a fixed ring that lives in the truck and is ready whenever an inspector asks for gauge verification.

Applications

Municipalities, inspectors, and sewer contractors use proving rings alongside deflection gauges when acceptance-testing newly installed flexible sewer pipe, confirming the pipe was properly bedded and backfilled without excessive out-of-roundness.

Questions on sizing or bulk pricing? Call (866) 514-3684 or email us — we ship within the USA and welcome tax-exempt purchasing for qualified accounts.