1. 10” Butterfly valves shall have single-offset disc and shall be of the lugged body style. All valves shall be suitable for use with ASME class 125/150 flanges, or specify. Valves shall provide bi-directional bubble-tight shutoff at pressures to 250 psi (1720 kPa) with ductile iron or aluminum bronze discs or 200 psi (1380 kPa) with 316 stainless steel disc/shaft. When specified, valves shall be NSF/ANSI 372 certified lead-free and NSF/ANSI 61 certified for drinking water. 2. Bodies shall be ductile iron. Lugged body valves shall provide bubble-tight shutoff up to the full valve rating on dead end service without the use of downstream flanges. 3. Discs shall be offset to provide an uninterrupted 360-degree seating edge and shall be nickel plated ductile iron, aluminum bronze or 316 stainless steel. The disc/shaft connection shall be splined. 4. Shafts shall be one-piece 410 stainless steel when valves have ductile iron or aluminum bronze discs and 316 stainless steel when valves have 316 stainless steel discs. Shaft diameters shall meet the AWWA C504, class 75B standard. Multiple shaft seals shall be provided to prevent leakage. 5. Elastomer seats shall fully line and be permanently bonded to the valve body. Seats shall be EPDM. Seats shall have integral flange seals so flange gaskets are not required.
