Double Flange

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Huamei’s Double-Flanged Butterfly valves is internationally compatible with other world flange standards such as ASME and ANSI classes such as pressure classes 150, 300, 600 and DIN ISO PN16, PN25, PN40, PN100. This promotes easy installation, alignment, and safe usage as these valves can be used in many different industries.

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How Double Flange Butterfly Valve Works

The disk stands as the flow control element of the valve. It is approximately the same diameter as the inside diameter of the adjoining pipe.

• The disk rotates on either a vertical or horizontal axis.
• When the disk lies parallel to the length of the pipe, the valve is fully opened.
• When the disk approaches the perpendicular position, the valve is shut.
• For throttling, intermediate positions can be secured in place by handle-locking devices.

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• Applicable for dead-end service.
• Can be used as an isolation valve.
• Compactness in design which requires less space.
• Quick in operation requiring less time to open or close.
• Available in a variety of sizes.
• Low-pressure drop
• High-pressure recovery （As compared with the Lug-Style and Wafer Style, Double-Flanged Butterfly Valves present the following major advantages: Easier to mount and center）
• Mechanically stronger in construction
• Most suitable valve for heavy-duty, large flow-handling applications such as wastewater handling systems and sea-water systems.

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Where to Use Double-Flanged Butterfly Valves

Double-Flanged Butterfly Valves are typically well-suited in handling large flows of liquids or gases, such as slurries or liquids with large amounts of solids. Typical applications are as follows:

• Wastewater
• Seawater/marine applications
• Bulk Storage
• Bulk Conversion Other
• Compressors
• Cooling Water, Circulating water
• Cruise Ship
• Facilities & Process Utilities
• Blowers
• Fire Protection
• Corrosive services
• Food processing, chemical, pharmaceutical

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Construction of Huamei Double-Flanged Butterfly Valve

How is it made/Manufacturing of Double-Flanged Butterfly Valves

Huamei fabricates Double-Style Butterfly Valve in a variety of materials of construction. The construction of this butterfly valve ensures that the following are fulfilled:

• Quarter-turn operation
• Ability to perform as a shutoff valve
• Restriction can be performed almost accurately
• Allow dead-end service or removal of downstream piping

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Furthermore, Huamei made certain that common valve problems are not left unanswered by designing and fabricating state-of-the-art Butterfly Valves, with extensive research and efforts of their in-house professionals, experts and engineers.

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Double-Flanged Butterfly Valve Basics

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Seat, Disk and Stem of a Wafer-Style Butterfly Valve

Disk

The disk is the flow closure part of the butterfly valve, bored in the middle to receive the stem. The usual method of securing the disk to the stem is by bolts or pins.

Huamei, however, does an alternate method involving shaping the upper stem bore to fit a squared or hex-shaped stem. This method is advantageous in corrosive applications and ensures uniform sealing as the disk is allowed to float and seek its center in the seat.

Stem

The stem extends beyond the bottom of the disk and fit into a bushing in the bottom of the valve. Huamei designed different material bushings to suit differences in chemical properties of the media being handled by the valve. Stem seals are made of O-ring seals. For corrosive substances, Huamei designed the valve stem in such a way that it cannot be in contact with the material being handled. This is to protect the valve stem from degradation and possibly failing the valve system.

Seat

The seat utilizes an interference fit between the disk edge and the seat to provide shutoff. The material of the seat can be made from many different elastomers or polymers. The seat may be bonded to the body or it may be pressed or locked in.

In high-performance butterfly valves, the shutoff may be provided by an interference-fit seat design or a line-energized seat design, where the pressure in the pipeline is used to increase the interference between the seat and disk edge.

Plastic Seat

The most common seat material is polytetrafluoroethylene (PTFE) or reinforced PTFE (RTFE) because of the wider range of compatibility and temperature range.

Metal Seat

Metal seats are also offered in high-performance butterfly valves. These metal seats allow a butterfly valve to be used in even higher temperatures to 1,000 Degrees F.

Fire Safe Seat

Fire-safe designs are offered that provide the shutoff of a polymer seat valve before a fire, and the metal seal backup provides shutoff during and after a fire.