AWWA C153

Applies to: Compact-body ductile-iron fittings (elbows, tees, reducers, crosses, caps, plugs) for water service NPS 3–16 at 350 psi working pressure; reduced laying length versus full-body AWWA C110 fittings; suited for tight excavations and directional drilling.

Does NOT cover: Full-body fittings (AWWA C110); NPS 18 and larger (C110 applies); fittings in wastewater or industrial service without supplementary specification; flanged connections (AWWA C110 flanged elbows/tees).

• Material: ductile iron per ASTM A536 Grade 65-45-12
• Cement-mortar lining per AWWA C104
• Bituminous outside coating (standard) or polyethylene encasement per project spec
• Pressure test at 2× working pressure (700 psi minimum)
• Marking: nominal pipe size, pressure class, and AWWA C153 designation
• Compact body dimensions per AWWA C153 tables

AWWA C153 compact fittings have largely replaced full-body C110 fittings in water distribution work due to their smaller trench box footprint and lower cost. The reduced wall section is structurally adequate for standard water distribution pressures but requires careful evaluation for high-surge systems.

Engineering note: For transmission mains with significant water hammer or surge potential (pump stations, pressure reducing valves, or rapid valve closure), run a surge analysis per AWWA M51 and verify that the C153 compact fitting pressure class exceeds the surge pressure envelope. If the surge pressure approaches 2× working pressure, specify C110 full-body fittings or restrained compact fittings at surge-critical locations.