Yes, but believe it are not there is a flow direction on them. So look
for the arrow pointing the direction of flow.If you want to adjust the
amount of flow use a globe valve.
Generally it is better to use fully open or fully closed condition.

its a quarter turn family valve taking less time and little space.
Please take care of insulation also.
*working pressure is also important:
-Types of b/f valves:
1. Resilient butterfly valve which has a flexible rubber seat. Working pressure 232 PSI

2. High performance butterfly valve which is usually double eccentric in design. Working pressure up to 725 PSI

3. Tricentric butterfly valve which is usually with metal seated design. Working pressure up to 1450 PSI
*Butterfly valves are valves with a circular body and a rotary motion
disk closure member which is pivotally supported by its stem.

A Butterfly valve can come in various styles including eccentric and high-performance valves.

These are normally a type of valve that uses a flat plate to control the flow of water.

As well as this, Butterfly valves are used on fire apparatus and
typically are used on larger lines, such as front and rear suctions and
tank to pump lines.

A Butterfly valve is also a type of flow control device, used to make a
fluid start or stop flowing through a section of pipe. The valve is
similar in operation to a ball valve.

Some supplementary tips

Butterfly valves on water lines should be manually operated only through
a geared mechanism to prevent slamming