The Butterfly Valve

Butterfly valves, such as AVFI valves, are used in the isolation or regulation of flow. Their operation is similar to that of ball valves, but they feature a disc-shaped closing mechanism. The disk is located in the middle of the pipe and a rod passes through it to connect to an actuator that’s located outside the valve/pipe. Rotation of the actuator turns the disc to control the flow all through the entire pipe.


The foremost manufacturers and suppliers offer both wafers as well as lug style butterfly valves featuring several and varying types of seats such as BUNA-N and EPDM. The major difference between the wafer and lug style butterfly valves is in the process of installing and mounting them.

  • Lug style butterfly valves: This category of butterfly valves feature ‘lugs’ or threaded valves and they can be installed into your system through the use of only bolts. Their installation process can be quite easy for individuals that understand valves, how they function, and how they are to be installed.
  • Wafer style butterfly valves: These are the more common option among the two. They are able to use both bolts and nuts during their process of installation, and even though they are much easier to replace or install, you will need to shut down the whole system before you can repair or replace them. They are so popular that you can get them from just any reliable and trustworthy AVFI valve supplier in Australia.


This is the next thing to seek when buying butterfly valves. The valves can be utilized for balancing/throttling as well as off/on service. They are much superior in ‘versatility’ when compared to globe or gate valves. They feature a considerably wider range of chemical resistance as a result of the choice of elastomeric liners as well as trim options.

Ease of operation

The valves have a ninety degrees – ¼-inch – turn for opening or closing. Globe and gate valves need several turns to either open or close. The ease of opening and closing certainly means that butterfly valves use less costly operators.


Installation costs are saved with lightweight butterfly valves in comparison to heavyweight cast iron valves; for example, a ten-inch butterfly valve could weigh fifty-five pounds, whereas a ten-inch iron-gate valve will weight not less than four hundred and ninety pounds. This can turn out to be crucial savings when you calculate it over a whole system. The heavier the system happens to be, the stronger the pipe hangers will be, and the more costly they shall become. Therefore, by taking the weight of any valve into consideration, you can actually decrease the cost of the piping system quite significantly.

If you are seeking an option that’s lighter in weight and lower in cost, then the butterfly valve is certainly a perfect fit. It could be utilized effectively in salt water, fresh water, chill water, and lube oil systems. Butterfly valves, such as those produced by AVFI valves, are offered with a wide variety of varying seats, each one with its own max psi and temperature rating to match the task that the valve is required to perform.

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