7 replies to this topic

[coal]

Dear all,

Under what kind of conditions would butterfly valves be preferred over the usually-used ball valves?

Thanks and regards.

[shan]

Comparing with ball valves, butterfly valves have less pressure drop but are unable to shut tightly. Butterfly valves are usually preferred in uncritical circuit such as cooling water system.

[ankur2061]

coal,

Several other advantages/features of Butterfly valves:

1. Cost much less than a ball valve of the same size (generally 2/3rd the cost of ball valve)

2. Many company standards recommend butterfly valves for size 6 inch and above since the price difference between a ball valve & butterfly valve of bigger comparable size (12 inch & above) is substantial.

3. With special seating material can also be used in critical services. Manufacturers/vendors can tailor it to suit the service.

Hope this helps.

Regards,
Ankur.

[coal]

Dear all,

Thanks for your useful information. =)

Regards.

[VikingUK]

I would personally ban butterfly valves !!! They have only one thing going for them.. they are cheap as chips... !!

[katmar]

I would personally ban butterfly valves !!! They have only one thing going for them.. they are cheap as chips... !!

A blanket statement like that is not helpful, and in fact not true. If you want to buy "cheap as chips" valves then you will get junk, whether they are butterfly, ball, gate or any other type of valve. I have used MANY butterfly valves over a looong time and have had excellent results. In some applications I would not even consider any other type of valve.

All valves must be used in the correct application. If you are looking for a half inch isolation valve on a pressure gauge you would select a ball valve before a butterfly - you can't even buy such a small butterfly valve. If you want a cooling water isolation valve on a 10" line it would be crazy to consider a ball valve, and the butterfly valve would be the right thing. The butterfly would be cheaper, lighter, smaller and easier to operate.

Butterfly valves come in many variations and if you pay a bit more for a double or triple offset valve you can get excellent shutoff and regulation properties. There are applications where the cheapest valves will be good enough, but at the other end of the scale you will find top class valves that can even be used for steam isolation.

[VikingUK]

I would personally ban butterfly valves !!! They have only one thing going for them.. they are cheap as chips... !!

A blanket statement like that is not helpful, and in fact not true. If you want to buy "cheap as chips" valves then you will get junk, whether they are butterfly, ball, gate or any other type of valve. I have used MANY butterfly valves over a looong time and have had excellent results. In some applications I would not even consider any other type of valve.

All valves must be used in the correct application. If you are looking for a half inch isolation valve on a pressure gauge you would select a ball valve before a butterfly - you can't even buy such a small butterfly valve. If you want a cooling water isolation valve on a 10" line it would be crazy to consider a ball valve, and the butterfly valve would be the right thing. The butterfly would be cheaper, lighter, smaller and easier to operate.

Butterfly valves come in many variations and if you pay a bit more for a double or triple offset valve you can get excellent shutoff and regulation properties. There are applications where the cheapest valves will be good enough, but at the other end of the scale you will find top class valves that can even be used for steam isolation.

Could not agree more with everything you have said.. butterfly valves are used when a cheap valve will do the job... !!!!!

[coal]

Dear all,

Thanks for sharing. =)

Regards.