Challenge

Week 14 challenge

SShubhankar Magade21 Feb 2023

Butterfly Valve

A butterfly valve is a valve that isolates or regulates the flow of a fluid. The closing mechanism is a disk that rotates. A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid. The valve may also be opened incrementally to throttle flow.

A 90° rotation of the handle provides a complete closure or opening of the valve. Large Butterfly valves are usually equipped with a so-called gearbox, where the handwheel by gears is connected to the stem. This simplifies the operation of the valve, but at the expense of speed.

Butterfly Valve is a rotary valve that uses a disc as closure member. The Disc shaped closure member is rotated 90 degree or there about to open or close the passage. The disc closes against the ring seal to close off the flow. Butterfly valves are the most specified valve type for moderate duty conditions in pipe sizes of two inches and larger.

Butterfly valves are normally wafer design fitted directly between piping flanges.

Used in

Liquid, gases, slurries, liquid with suspended solids.

Advantages

High Capacity

Tight Shutoff

lightweight

low Maintenance

Low Pressure drop

Disadvantages

High torque required for control

Components of Butterfly Valve are as Follows:

Butterfly valve Body
Shaft Stem
Plate
Retainer
Pin
Nut
Bolt

Butterfly Valve

Butterfly valves generally have bodies that fit between two pipe flanges

Following are the Images of Butterfly Valve which i have being designed -

Stem Shaft

Butterfly valve Stem: The stem of the butterfly valve may be a one-piece shaft or a two-piece (split-stem) design. The stem in most resilient seated designs is protected from the media, thus allowing an efficient selection of material with respect to cost and mechanical properties.

The valve shaft, often also referred to as the stem, is the component that connects the disc to the actuation mechanism and transmits the torque through itself.

Disc Plate

Attached to the stem shaft body is the disc that functions as a gate that stops or throttles fluid flow, it can be considered equivalent to a gate in a gate valve, or a ball in a ball valve. There are many variations in disc design, orientation, and material in order to improve flow, sealing, and/or operating torque.

Retainer plate

Retainer plate is attached at the top of the butterfly valve. It is held in between Butterfly valve and Stem Shaft. It supports the Stem Shaft while operations are being carried out. It gives strength to the butterfly valve as well as stem shaft.

This part helps to retain or to fix the shaft with the body of the butterfly valve. It prevents the shaft from coming out of the body and keeps it in position for the proper functioning of the disc inside the body.