Premium Double Eccentric BFVs

SIERRA model 7500 is a double flanged double eccentric disc seated valve butterfly valves. This model is suitable for high-pressure waterworks applications, the 7500 butterfly valve is an excellent valve for isolation purposes.
SIERRA produces double eccentric butterfly valves 7500 premium series in sizes DN200–1000, engineered with a strong emphasis on durability and performance.

Design Features

Double Eccentricity: The double eccentric butterfly valve has 2 offsets. This offset is the displacement of the shaft from the centerline.

• The first offset is the displacement of the shaft from the centerline of the disc seat and body seal. This maintains continuous sealing surface during the opening and closing of the valve.
• The second offset is the displacement from the centerline of the pipe/bore. This is to allow the disc and seal right to easily lift off and away from the body seat.

Hydrodynamic Disc Design: A hydrodynamic disc design means the butterfly valve does not fight the water, instead it lets the water flow smoothly, saving energy (energy efficiency) and protecting the system.

Dry Shaft Design: A dry-shaft butterfly valve is designed to keep the shaft protected from the fluid in the pipeline.

Stainless Steel Retainer: The disc retainer is a mechanical ring used to hold and secure the rubber gasket (disc seal) onto the disc of a butterfly valve. The retainer ensures the disc seal stays in place during operation, especially under high pressure or bi-directional flow.

Bi-Directional Sealing: Bi-directional butterfly valves, designed to provide tight shutoff and reliable operation in both flow directions (from either side of the valve). Or the valve can seal and operate with fluid pressure applied from either side of the disc.

Stainless Steel Body Seat: The body seat is the sealing surface inside the valve body that the disc seal presses against to achieve shutoff. The SIERRA welded stainless steel seat design provides a lower coefficient of friction during operation.

Material Standards 

Body, Disc, Gland and Bottom Cover ——— Ductile Iron EN-GJS-500/7  Or  Ductile Iron EN-GJS-400/12 Acc. To (EN1563)

Body Seat ——— Stainless Steel Grade 309L

Retaining Ring ——— Stainless Steel Grade 316 

Disc Seal ——— EPDM Rubber

Driving Shaft & Stub Shaft ——— X20Cr13 (AISI 420)

Valve Bearing ——— Self-Lubricating Bearing (PTFE/Steel/Tin)

Body Sleeve, Disc Sleeve (Dry Shaft Mechanism) ——— Bronze