ASTM D2996

Applies to: Filament-wound fiberglass reinforced polymer (FRP/GRP) pipe with thermosetting resin for chemical process, cooling water, wastewater, and offshore firewater service; classified by liner type, glass content, and pressure rating based on hydrostatic design basis (HDB).

Does NOT cover: Centrifugally cast FRP pipe (ASTM D2310); FRP pipe fittings (separate product standards); fire-resistance rating without supplementary fire testing; above-ground installation without UV protection specification.

• Liner resin type and minimum thickness (chemical barrier layer)
• Structural wall glass-to-resin ratio (by weight)
• Hydrostatic design basis (HDB) per ASTM D2992 (cyclic or static pressure testing)
• Proof test at 1.5× HDB for acceptance
• Joint system qualification (bell-and-spigot, flanged, or butt joint)
• UV stabilization or coating for outdoor exposure
• Chemical compatibility of both liner and structural layer resins

ASTM D2996 filament-wound FRP pipe is used where corrosion resistance of thermoplastics is insufficient and metallic pipe would require expensive alloys. Common liner resins are epoxy (general chemical resistance), vinylester (concentrated acids and alkalis, bleach), and isophthalic polyester (water service and moderate chemical exposure). The filament-wound construction allows pressure rating optimization by varying winding angle — ±55° for balanced hoop/axial loading, ±75° for axial-load-dominated design.

Engineering note: For chemical service, verify chemical compatibility of BOTH the liner resin and the structural layer resin against the service fluid — the liner prevents direct fluid contact but chemical diffusion can attack the structural glass-resin interface over time. Specify the liner resin type explicitly in the material specification; "FRP pipe" without resin specification is unacceptably vague for chemical service procurement.