|WikiProject Technology||(Rated Start-class)|
I'm removing the entire "Fire protection butterfly valves" section, as it is an obvious spam from NNI Inc. The text is taken verbatim from the product description of the product it's plugging. Kolbasz 20:25, 6 October 2006 (UTC)
- The pressure ratings could also be spam. They look like they are for a particular brand of valve. Ian01 (talk) 21:24, 29 December 2007 (UTC)
"Butterfly valves can come in two body types, affecting installation and maintenance: lugged or wafer."
This would benefit greatly from illustrations
I know, you then get into the question of whose product photos to use -- you need either multiple companies or you need a new sketch which avoids explicitly referencing any of 'em -- but it's sorta frustrating that folks need to do secondary searches to actually find out what a butterfly valve looks like, when that may be the single most important piece of information. —Preceding unsigned comment added by Keshlam (talk • contribs) 15:25, 20 September 2007 (UTC)
can I submit sth here? Doncloud
This appears to be at least 3 articles rolled into one and there is a lot of repetition. Does anyone object if I slim it down? Biscuittin 11:47, 28 September 2007 (UTC)
Needs more information
I'm willing to have a bash at improving this article, but specifically on the triple offset butterfly valves, (which I have never heard of as TOTS and I'm in the industry!) - is it ok for me to just work on this particular part of it? Gertie100 (talk) 15:34, 23 April 2008 (UTC)
Lots of missing info and references
Excellent fire protection standards have been written by the American Petroleum Institute (API - http://www.api.org/). The institute also has excellent leak tolerance standards. Other standards bodies for butterfly valves include the American National Standards Institute (ANSI - http://www.ansi.org/), the International Standards Organization (ISO - http://www.iso.org/iso/home.htm), and the Deutsche Industrialize Norme (DIN - http://www.din.de/cmd?level=tpl-home&contextid=din). The American Water Works Association (AWWA - http://www.awwa.org/) also has a standard particular to butterfly valves used for public water supply, though the standard is old and somewhat outdated.
The second poster's concern that there is a third type of butterfly body is justified, especially since there is a picture of a Flanged Body Valve in the definition as of this writing.
The following should be added: Common examples of butterfly valves such as those on a vehicle's carburetor or throttle body; references to media (the fluid being controlled), wetted parts, the four main components of an industrial butterfly valve (body, disc, stem, seat), the split body valve (wafer and lug type), installation between plastic flanges as opposed to steel flanges, strengths of the butterfly valve (weight, cost, flow control, resilient seated resistant to abrasive media, etc.), the weaknesses of butterfly valves (pressure range, flow reduction, susceptibility to watter hammer, etc.), and teflon seated valves both split body and offset disc. Serebren (talk) 18:56, 20 May 2008 (UTC)
The material of disc and sealing, purpose, application is missing.
Some times butterfly valves used in pneumatic sand conveying. Sand is abrasive, thus the proper selection of disc & seal material is very important.
If "tricentric" is purely a brandname and does not refer to a specific design type then I doubt that it should be mentioned as one of the types. --CopperKettle 16:13, 27 September 2009 (UTC)
Likewise, the references to the so called improvements due to double or triple offsets, should be explained in an unbiased "white paper" style. I would even encourage the company that has trademarked "tricentric" to defend their design in this manner. Otherwise readers may dismiss this as branding.
If I had to guess, there may be merit to having each half of the plate offset from it's axis. This would allow the valve to seal with a seat rather than the pipe's wall. This would avoid almost all of the wiping motion that could where a valve and prevent failure because the valve can be supported by the sealing surface. I have also seen valves that are offset so that the flow tends to open or close the valve by pushing on the side that creates a larger moment. However, I have still only accounted for 1 or 2 (if you count each half of the plate as an offset - weak) offsets or eccentricities. Cam Forman (talk) 03:07, 7 November 2012 (UTC)
- 'Tricentric' is a single brand name, but triple offset or triply eccentric valves are an important form and should be covered here (a section has just been removed). They're an important form for metal-metal seating, rather than an elastomer, when a good seal is required. Andy Dingley (talk) 01:04, 24 January 2017 (UTC)
Has this article been machine-translated from another language? The English is really awkward and ambiguous. It would be nice if someone who understands the subject and speaks good English would have a go at it.
Also why are the valves called "eccentric"? "Eccentric" means "off-centre". I don't get it, the article is very unclear, and as someone mentioned, is DYING for diagrams.
I came here from the article for Vibraphone. I at least understand that article better now.