Telephone Duct Type C | PVC Conduit | Direct Burial & Encasement | 20' Bell End

Telephone Duct Type C | Direct Burial & Concrete Encasement — Product Overview

Type C telephone duct is the heavy-wall grade of Prime Conduit's rigid PVC duct line, built for underground telecommunications work. It is the only one of the three telephone-duct types approved for direct burial as well as concrete encasement, which is why it is the common choice for utility duct banks, campus builds and municipal telecom upgrades.

What separates Type C from the lighter Type B is stiffness. Type C carries a pipe stiffness of 120 lb/in/in against Type B's 30, and a collapse pressure of 36.6 psi against 9.2 — four times the resistance to crushing and deflection under backfill. That margin is what lets it go in the trench without a concrete envelope around it.

Each length is 20 ft 3 in overall, including the factory bell, so sticks join without separate couplings. The standard bell is 3 in deep; a 6 in long-bell version is also stocked for installations that want the extra engagement. Gray and white are both available — colour is normally set by the utility's own duct-bank colour code.

Manufactured to NEMA TC-10 and harmonized with Bellcore/Telcordia CAO8546. For direct bury or concrete encasement only — not for exposed applications.

Key Features

• Direct Bury or Concrete Encasement: The only telephone-duct type rated for both, so one part covers the whole run.
• 0.150 in Heavy Wall: Prime's minimum wall for Type C, against 0.090 in for standard Type B.
• 120 lb/in/in Pipe Stiffness: Four times Type B, with 50 ft·lb minimum impact resistance at 32°F.
• 36.6 psi Collapse Pressure: Holds its round under backfill and compaction loads.
• Factory Bell End Included: 3 in standard bell, or a 6 in long bell for deeper engagement. No separate couplings needed.
• Gray or White: Match the duct-bank colour code on your spec.
• NEMA TC-10 and Bellcore/Telcordia CAO8546: Meets the standards utility and telecom specs normally cite.
• Priced by the Foot, Sold in Whole Bundles: Order in multiples of the 1,260 ft bundle — 1,260 ft, 2,520 ft, 3,780 ft and so on.
• View Type C Split Sleeve Couplings Here > LINK
• View Type C Split Kits Here > LINK

Which Telephone Duct Type Do I Need?

Type C substitutes for Type B in an encased run; Type B does not substitute for Type C in direct burial. If your spec calls for Type B or Type D, contact us — they are not stocked on this listing. Values from Prime Conduit's P&C Duct & Telephone Duct specification per NEMA Standard TC-10. Confirm the required duct type with the utility or engineer of record.

Telephone Duct Type C — Specifications

Overall length is 20 ft 3 in including the bell. Bundle quantity is the order increment — the 1,260 ft bundle is ordered as 1,260 ft, 2,520 ft, 3,780 ft and so on. Weight is shown per 100 ft; the per-foot shipping weight is 1.50 lb. Source: Prime Conduit Telephone Duct brochure.

Material Properties

Technical Document

• Prime Conduit Telephone Duct Brochure > LINK