Cherne® PROVING RING, 8 IN. 7.5% Deflection, SDR 35

The Cherne® Proving Ring, 8 in., 7.5% Deflection, SDR 35 (part #73253) is a precision verification ring used to confirm that an 8 in. SDR 35 deflection gauge (mandrel) built to the 7.5% deflection specification is still sized correctly. Passing the mandrel through the proving ring before testing proves the gauge hasn't worn or deformed, keeping your deflection results beyond dispute.

Key Features

• Gauge verification — validates your 8 in., 7.5% deflection gauge before and after testing so results hold up under review
• 7.5% deflection specification — matched to jurisdictions that test SDR 35 sewer pipe to the 7.5% deflection criterion rather than 5%
• Fast field check — simple pass/no-pass confirmation, no lab equipment or micrometers required
• Part of the Cherne® deflection testing system — Cherne offers proving rings in both 5% and 7.5% deflection versions across standard sizes

Applications

Municipal inspectors and sewer contractors use proving rings to certify deflection gauges ahead of post-installation mandrel testing on 8 in. flexible SDR 35 PVC sewer pipe (ASTM D3034), verifying proper bedding and backfill.

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.