Graphite Flanged DN80 PN 40 Triple Eccentric Butterfly Valve

Article: 5040
Flanges: UNI EN 1092-2 PN 40, ASME 16.5
Face to face length: DIN 3202 F16 Design EN 12516, API 609
Installation: horizontal, vertical
FIELDS OF APPLICATION • Water • Industrial plants • Oil and refineries• Steam • Gas

Epoxy paiting suitable for drinking water applications.

A Butterfly valve is a quarter-turn rotary motion valve, that is used to stop, regulate, and start the flow. Butterfly valves are a quick open type. A 90° rotation of the handle can completely close or open the valve. Normally, they are used in systems where a positive shut-off is not required. In this article, you will learn about following types of Valve.

• Wafer Type
• Lug Style Type
• Flanged Type
• Butt Welded Ends Types
• Zero offset
• Double Offset
• Triple Offset

Large Butterfly valves are usually equipped with gearbox type actuator, where the handwheel is connected to the stem via a gearbox. This will reduce the force but at the same time reduce the speed of the operation. This type of valve should be installed in the open position. If the valve is closed during installation, the rubber seat will wedge against the valve disc and make it difficult to open.

Types of Butterfly Valves Based on Body Construction

Based on the type of ends of the body butterfly valves are available in following types.

• Both Flanged Ends

• Wafer Type Ends

• Lug Type Ends

• Butt Welded Types Ends

Water Type

The wafer body is placed between pipe flanges, and the flange bolts surround the valve body. A wafer type butterfly valve is easy to installed but it cannot be used as an isolation valve.

Seat Types

Butterfly valves can be metal-to-metal seated, soft seated, or with a fully lined body and disc. The first image is of a soft seated fully lined body and disc valve. Second, is a soft seat with metal disk and the third is metal to metal seat type valve.

Triple Offset Butterfly Valve

In Triple Offset design the third offset created by the geometry design of the seating surface.

The seat is machined into an offset conical profile resulting in a right-angled cone. You can see this in the

third image with small enlargement of seating angle.

This ensures frictionless stroking throughout it's operating cycle. Contact is only made at the final point of

closure with the 90° angle acting as a mechanical stop; the Metal seated valve uses triple offset design.