ANSI AWWA C115 - A21.15-20 PDF

Full title and description

ANSI/AWWA C115/A21.15-20 — Flanged Ductile‑Iron Pipe With Ductile‑Iron or Gray‑Iron Threaded Flanges. This American National Standard specifies minimum requirements, dimensions, materials, pressure ratings, manufacturing and inspection practices, marking, and testing for flanged ductile‑iron pipe (3 in. through 64 in. / 80 mm through 1,600 mm) furnished with ductile‑iron or gray‑iron threaded flanges for potable water, wastewater, and reclaimed water service.

Abstract

This standard provides the technical and dimensional requirements needed to produce, inspect, purchase, and accept flanged ductile‑iron pipe with threaded flanges. It defines allowable materials and mechanical properties for the pipe and flanges, flange and bolt dimensions and tolerances, hydrostatic test requirements and pressure ratings, marking and identification, and optional purchaser‑specified items (for example, flange material). The goal is to ensure interchangeability, safe service pressures, and reliable field performance of flanged ductile‑iron piping components used in water and wastewater systems.

General information

• Status: Current (active AWWA standard; ANSI approved edition published 2020). Current as of February 19, 2026.
• Publication date: August 2020 (designated C115/A21.15-20).
• Publisher: American Water Works Association (AWWA); ANSI‑approved American National Standard.
• ICS / categories: Pipes and pipelines; water distribution components — commonly classified under ICS 23.040 (Pipes and fittings) and related building/waterworks service categories (also cross‑referenced in waterworks standards lists).
• Edition / version: ANSI/AWWA C115/A21.15-20 (2020 edition).
• Number of pages: 36 pages (2020 edition).

Scope

Applies to 3‑in. through 64‑in. (80 mm through 1,600 mm) flanged ductile‑iron pipe furnished with ductile‑iron or gray‑iron threaded flanges for potable water, wastewater, and reclaimed water service. The standard establishes dimensional and material requirements, pressure ratings (typical maximum working pressure of 250 psi; selected flange sizes and materials may be permitted up to 350 psi for certain smaller sizes), testing and inspection procedures, and marking/identification requirements necessary for procurement, fabrication, and acceptance.

Key topics and requirements

• Dimensional requirements and tolerances for flanged pipe and threaded flanges (3 in.–64 in.).
• Permitted flange materials: ductile‑iron or gray‑iron (owner may specify flange material where desired).
• Pressure ratings and maximum working pressures (typical 250 psi; allowances for higher ratings on specified sizes/materials as noted in the standard).
• Mechanical and material property requirements for pipe and flange castings (iron grades, tensile/elongation, etc.).
• Surface preparation, cleaning, and optional coatings/linings referenced (coordination with lining/coating standards where applicable).
• Hydrostatic testing and verification procedures for production acceptance.
• Marking, identification, and documentation requirements for shipment and installation.
• Requirements for bolts, nuts, gaskets, and assembly clearances as they relate to flange connections.

Typical use and users

Used by water and wastewater utilities, municipal and regional agencies, consulting and design engineers, pipe manufacturers and fabricators, procurement/specification writers, contractors and installers, and testing/certification bodies. Typical applications include distribution mains, force mains, pump station piping, and other waterworks situations where flanged connections are required for assembly, maintenance, or special appurtenances.

Related standards

Commonly referenced and used alongside other AWWA and industry standards such as ANSI/AWWA C151/A21.51 (ductile‑iron pipe), ANSI/AWWA C110/A21.10 (fittings), ANSI/AWWA C104/A21.4 (cement‑mortar lining), ANSI/AWWA C111/A21.11 (rubber‑gasket joints), ANSI/AWWA C150/A21.50 (thickness design), ANSI/AWWA C116/A21.16 (fusion‑bonded epoxy coatings), installation standards (AWWA C600), and health/safety/certification standards such as NSF/ANSI 61 where potable water contact is required. Industry flange and fastener standards (for example applicable ANSI/ASME bolt and flange standards) may also be cross‑referenced.

Keywords

flanged ductile‑iron pipe, threaded flanges, ANSI/AWWA C115, A21.15, potable water, wastewater, reclaimed water, flange dimensions, pressure rating, hydrostatic test, ductile iron flange, gray iron flange, pipe specification, AWWA standard.

FAQ

Q: What is this standard?

A: ANSI/AWWA C115/A21.15-20 is the AWWA American National Standard that sets minimum requirements for flanged ductile‑iron pipe furnished with ductile‑iron or gray‑iron threaded flanges for water, wastewater, and reclaimed water service.

Q: What does it cover?

A: It covers sizes 3 in. through 64 in. (80 mm through 1,600 mm) and specifies materials, dimensional tolerances, pressure ratings, testing (including hydrostatic tests), marking, and inspection requirements needed for manufacturing, purchasing, and accepting flanged ductile‑iron pipe with threaded flanges.

Q: Who typically uses it?

A: Water and wastewater utilities, design and consulting engineers, manufacturers and fabricators of ductile‑iron pipe and flanges, specifiers and purchasers, contractors, and testing/certification organizations use this standard to ensure compatibility, safety, and performance of flanged pipe systems.

Q: Is it current or superseded?

A: The 2020 edition (ANSI/AWWA C115/A21.15-20) is the current published edition (published August 2020). As with many AWWA standards, periodic reviews and committee activities occur; a public comment/review cycle was conducted in 2025. Until a later edition is formally published and announced, the 2020 edition remains the active standard.

Q: Is it part of a series?

A: Yes. C115/A21.15 is part of the AWWA C100/C200 series of standards addressing ductile‑iron pipe and fittings and is often used together with related AWWA standards (for linings, fittings, joints, thickness design, and installation) to form a complete specification package for ductile‑iron piping systems.

Q: What are the key keywords?

A: flanged ductile‑iron pipe; threaded flanges; pressure rating; AWWA C115; A21.15; ductile iron; gray iron; potable water; hydrostatic test; flange dimensions; pipe specification.