What are the parts of a butterfly valve?

The butterfly valve consists of only four main components: body, disk, stem and seat. Body. Butterfly valves generally have bodies that fit between two pipe flanges. The most common body designs are lug and wafer.

How does a butterfly valve works?

Butterfly valve: working principle The construction of a butterfly valve is relatively simple, with the rotation of the valve disc controlling the fluid flow. In the closed position, the disc blocks the valve bore while in the open position, the disc is oriented perpendicular to the flow direction to allow flow.

What is stem in butterfly valve?

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.

Does butterfly valve have flow direction?

The butterfly valves are bi-directional but do have a preferred flow direction. It’s however strongly recommended to install the valves in the preferred flow direction, as it will extend the valve’s life span and will also lower the operating torque.

How do butterfly valves allow water flow?

Butterfly Valve At the center of a butterfly valve is a rotating disc. Like ball valves, this movable element is controlled by the quarter-turn of a handle. When the handle is turned, this disc flares open, allowing fluid to pass through the pipe.

Why is it called a butterfly valve?

The butterfly valve gets its name from how the movement is similar to a wing for flight. The rod is analogous to a butterfly’s body, while the disc moves like a butterfly wing. A butterfly valve’s motion is similar to that of a butterfly that has landed with the wings moved up and down with a 90-degree motion.

Which way do you install a butterfly valve?

API butterfly valves are bi-directional and may be installed with flow in either direction, vertically, or horizontally. If a choice of stem position exists, the valve should be installed with the stem in the horizontal position; this will minimize seat wear by distributing the stem and disc weight evenly.

Does flow direction matter in butterfly valve?

Do butterfly valves have flow?

Butterfly valves may be used for flow in both directions. Unlike a ball valve, the disc is always present within the flow, therefore a pressure drop is always induced in the flow, regardless of valve position.

Are butterfly valves bidirectional?

Which way does a butterfly valve go?

If upstream disturbances are not a concern, larger butterfly valves should always be installed with the shaft axis being horizontal.