DeZURIK BAW AWWA Rubber-Seated Butterfly Valve

A water-works butterfly valve built around a molded-in rubber seat

The DeZURIK BAW is a rubber-seated butterfly valve made for water and wastewater plants, distribution mains, power plants and industrial process water. The bulletin states that every valve follows AWWA C504 for sizes 3 to 72 in (80 to 1800 mm) and AWWA C516 from 78 in (2000 mm) up, and that each unit is given a hydrostatic, seat leakage and performance test before shipment.

Its central idea is a seat that is molded into the body instead of sitting on the disc. A solid 316 stainless steel disc edge plows through tuberculation and sediment in old pipelines while the rubber stays stationary, which DeZURIK presents as the reason for a seat that remains maintenance free. Valves up to 36 in were prototype tested in the company flow laboratory and cycled up to 10,000 times as AWWA C504 requires.

BAW technical specification

Design details that matter in service

On valves from 3 to 20 in the body is fully rubber lined, so no inner coating is needed, and the seat carries a spherical sealing surface that gives a 4 degree sealing range. That range lets the actuator be trimmed while the valve is under pressure and flow. Integral shaft bearing seals in the upper and lower journals keep sediment and mineral deposits away from the bearings, which are lubrication free.

From 24 in upward the seat is retained in a dovetail groove by an epoxy wedge injected with the disc closed, at a pressure set by the valve class. The seat is adjustable and replaceable from either side of a pressurized valve, as AWWA C504 requires for large sizes. Disc-to-shaft pinning uses a stainless torque screw up to 12 in, a tangential pin from 14 to 20 in and a tapered pin from 24 in.

Large valves have an open, non-hollow disc structure that lets water pass through the center ports, so each wall can be inspected for shrinkage and core shift after casting. An adjustable thrust bearing assembly in the lower shaft holds the disc position in every installation orientation and absorbs disc weight, hydraulic force and axial shaft loads. The rubber bond is proven by the AWWA C504 pull test: a 1 in strip must withstand at least 75 lb before it tears away from the body, and the rubber must tear before the bond fails.

Selecting and ordering a BAW

The bulletin builds the order code in the sequence style, size, end connection, body material, seat and disc seat pairing, AWWA class and disc and shaft options, followed by the actuator. A printed example reads BAW,24,F1,CI,NBRN-NBR,150B,DI-S1*Actuator. All orders from 28 in must state the AWWA C207 flange class, and mechanical joint valves are recommended with buriable actuators.

Manual operation is offered through lever actuators on small sizes, handwheel, chainwheel or 2 in square nut rotary actuators sized to AWWA C504 rim-pull limits; G-Series worm gear actuators cover 80 to 750 mm and LA-Series actuators cover 30 to 72 in with 450 ft-lb input stops. Confirm line pressure, seat material and actuator before ordering.

Where the BAW fits and what to confirm

As general engineering context, rubber-seated AWWA butterfly valves are the usual isolation choice in desalination intake and product water lines, municipal transmission mains, cooling water circuits and pump stations across Oman and the Gulf. Check the fluid, any chlorine or brine content, and the seat elastomer against the bulletin before selecting NBR or EPDM.

Pump control systems built around AWWA butterfly valves are described in the bulletin. Related DeZURIK items on our site follow in the Butterfly Valves category. The attached bulletin 43.00-1 (11/2025) holds the weights, Cv tables, torque data and materials lists; send size, class, end connection and actuator when requesting a quotation from Seven Star LLC.

Using the BAW in Oman and the GCC

AWWA butterfly valves are standard equipment on water transmission mains, reservoirs, pumping stations, desalination product water lines and treated effluent networks in the region. Utilities and consultants often name AWWA C504 in their specifications, so the stated compliance makes the BAW a practical candidate for these projects. The molded-in seat design suits older mains where tuberculation and sediment are present.

For buried service, confirm the operator type, the extension stem and the coating system, and for desalination plants check the disc and shaft materials against the chloride content of the water. Large valves should be lifted and stored as described in the manual, with the disc slightly open to protect the seat.

Information to send with an enquiry

• Size, pressure class and flange drilling
• Fluid, temperature and whether the valve is buried or above ground
• Operator: manual gear, electric or pneumatic actuator
• Project specification and quantity