Butterfly or Diaphragm

[ryane]

My original source for butterfly valves fell through so Im back to hunting a new source, and this got me thinking - butterfly valves or diaphragm valves?

I don't personally have much experience with diaphragm valves so I'd tend to lean towards getting butterfly's (though they are a bit more $$ vs diaphragm)

If all things are equal (price, size, etc) and both are pneumatically actuated, which would you chose and why?

 

[trimixdiver1]

My original source for butterfly valves fell through so Im back to hunting a new source, and this got me thinking - butterfly valves or diaphragm valves?



I don't personally have much experience with diaphragm valves so I'd tend to lean towards getting butterfly's (though they are a bit more $$ vs diaphragm)



If all things are equal (price, size, etc) and both are pneumatically actuated, which would you chose and why?

I like diaphragm valves on process that needs to be sanitary and keep the transmission path clean (grain).

Butterfly's are great as a dump valve, so I have those as a MLT dump.

 

[ryane]

I like diaphragm valves on process that needs to be sanitary and keep the transmission path clean (grain).

Butterfly's are great as a dump valve, so I have those as a MLT dump.

arent butterfly valves considered a sanitary valve? when open all parts of the valve are exposed allow a true CIP no?

This might be a moot conversation depending on if a quote I just got back ($70/ea 1"TC butterfly) was accurate

 

[aangel]

Butterflies aren't considered CIP/Clean, at least by a maker of valves: http://hollandaptblog.com/2014/01/10/sanitary-butterfly-valves-overview/ They do say that since butterfly valves are used all the time in industry, "sanitary enough" might be a way to think about it.

Even diaphragm valves need to be "diaphragm isolation" type, and be mounted at a horizontal incline/decline to enable full draining to be considered clean.

In other news, an NPT end-cap left in my (currently empty/off) beer fridge grew nasty black mold on the dry plumber tape on its threads, after a week. (grumble grumble).

If you manage to find actuated (electric or pneumatic is fine) 2 or 3-way diaphragm isolation valves for a reasonable price, let me know. I've seen a bunch on alibaba but it's alibaba.

 

[ryane]

Butterflies aren't considered CIP/Clean, at least by a maker of valves: http://hollandaptblog.com/2014/01/10/sanitary-butterfly-valves-overview/ They do say that since butterfly valves are used all the time in industry, "sanitary enough" might be a way to think about it.

According to that link its only not suitable for biopharmaceuticals, but extensively used in food and beverage industries.......

If you manage to find actuated (electric or pneumatic is fine) 2 or 3-way diaphragm isolation valves for a reasonable price, let me know. I've seen a bunch on alibaba but it's alibaba.

Define reasonable......

Alibaba is one thing, AliExpress while not 100% different has a different payment setup so you have some recourse for non-delivery

 

[aangel]

According to that link its only not suitable for biopharmaceuticals, but extensively used in food and beverage industries.......




Define reasonable......

Alibaba is one thing, AliExpress while not 100% different has a different payment setup so you have some recourse for non-delivery

Reasonable...say <$100 shipped for 2-way or <$150 shipped for 3-way valves of between 0.5 and 0.75" pipe size?

 

[trimixdiver1]

Look to ebay for your diaphragm valves. I see them for 10 bucks all the time. Pneumatics for about 50.
View attachment ImageUploadedByHome Brew1421750452.473722.jpg

As to CIP, diaphragm valves also shouldn't be mounted so the stem is vertical, instead it should be at a about a 45deg angle to allow draining.
View attachment ImageUploadedByHome Brew1421750570.621094.jpg

 

[aangel]

Nice! So I think I read a while back that 15 degree incline's required. Is it really 45? That'll make my plumbing plans somewhat convoluted.

 

[trimixdiver1]

Nice! So I think I read a while back that 15 degree incline's required. Is it really 45? That'll make my plumbing plans somewhat convoluted.

Maybe I should clear it up, I'm guessing on the degree. I'm not talking about incline but if the valve is horizontal, it should be so the handle is to the side to allow self draining. I wish I could find a pic. Hope you understand.

 

[aangel]

According to that link its only not suitable for biopharmaceuticals, but extensively used in food and beverage industries.......




Define reasonable......

Alibaba is one thing, AliExpress while not 100% different has a different payment setup so you have some recourse for non-delivery

Maybe I should clear it up, I'm guessing on the degree. I'm not talking about incline but if the valve is horizontal, it should be so the handle is to the side to allow self draining. I wish I could find a pic. Hope you understand.

Is this what you mean? If the valve is a weir-type mechanism, there's that vertical "lip" in the steel bottom, seemingly designed to improve the seal ability of the valve's seat. If I mounted the valve "sideways" with the handle sticking out horizontally, that lip wouldn't be holding any liquid in. That plus the 15 degree tilt that I read about somewhere should equal full-draining.

 

[trimixdiver1]

Is this what you mean? If the valve is a weir-type mechanism, there's that vertical "lip" in the steel bottom, seemingly designed to improve the seal ability of the valve's seat. If I mounted the valve "sideways" with the handle sticking out horizontally, that lip wouldn't be holding any liquid in. That plus the 15 degree tilt that I read about somewhere should equal full-draining.

Yep

Try, brewershardware.com for the butterfly's.

 

[ryane]

Look to ebay for your diaphragm valves. I see them for 10 bucks all the time. Pneumatics for about 50.

Any brand in particular?

I often see Gemu on there but they usually have an odd piping configuration and they are used - though I guess I could easily cut off the weird piping

And are the valves you see for that price new or used?

 

[trimixdiver1]

Any brand in particular?



I often see Gemu on there but they usually have an odd piping configuration and they are used - though I guess I could easily cut off the weird piping



And are the valves you see for that price new or used?

Used, but the rebuild kits are cheap if needed.

 

[kickflip_mj]

Used, but the rebuild kits are cheap if needed.

I found a crap ton of actuators, but no valve bodys

 

[kickflip_mj]

Do any of you guys know if ITT valve bodys will fit on Gemu actuators? they seam identical

 

[trimixdiver1]

As long as the DN numbers match, I think so.

 

[kickflip_mj]

Thats what I was thinking, my other problem is knowing how they seal. should the product number tell me on seal type?

 

[orangehero]

As long as the DN numbers match, I think so.

I was under the impression the DN numbers refer to the flanges, but beyond that everything is proprietary.

Try contacting the manufacturers, I have found their technicians to usually be very helpful, especially if you mention you're working on a homebrew system.

In the model number there should be a designation of seal type which you should be able to look up on the manufacturer's website. Most commonly it's Buna-N or Buna-N backed PTFE.

 

[kickflip_mj]

I was under the impression the DN numbers refer to the flanges, but beyond that everything is proprietary.

yeah DN refers to size. DN 15 in .5" DN 25 in 1" etc

 

[orangehero]

yeah DN refers to size. DN 15 in .5" DN 25 in 1" etc

Keep an eye on the auctions and you will find GEMU's eventually. For some reason ITT's are more common. Good luck!

 

[trimixdiver1]

yeah DN refers to size. DN 15 in .5" DN 25 in 1" etc

Cool, learn something new everyday. This is my first time dealing with diaphragm valves. Not too many in a nuclear power plant.

 

[kickflip_mj]

Keep an eye on the auctions and you will find GEMU's eventually. For some reason ITT's are more common. Good luck!

I have found a crap ton of Gemu's for cheap, but they all are missing the valve body. I was hoping to find a valve body and pair up an actuator, but it seams like a dumb idea. I cant wait to change my hard piping to 100% sanitary CIP

 

[kickflip_mj]

Keep an eye on the auctions and you will find GEMU's eventually. For some reason ITT's are more common. Good luck!

Ill need all the luck i can get, because I need 5 valves minimum :cross:

 

[trimixdiver1]

I have found a crap ton of Gemu's for cheap, but they all are missing the valve body. I was hoping to find a valve body and pair up an actuator, but it seams like a dumb idea. I cant wait to change my hard piping to 100% sanitary CIP

It's great, but no matter what, it hurts the pocket book.

If you email the guy on ebay (Neil) he will help you out.

I have a 1/2 sanitary diaphragm with inline ball valve I could let go.