Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Valves library

  1. Nov 7, 2009 #1
    Hi
    I hope that this won't be treated like spam or something. I just used search engine to find place where I can find people who may be interested to help me building something that I call "valve library". I started small web site with intention to create online place where You can find all informations about all valves. I mean from base descriptions and specifications for ordinary people and students up to advanced info for professionals.

    If You are interested to help, please visit my http://valvesinfo.blogspot.com" [Broken] type, valve manufacturer or any other info that you think that can be useful for this library.

    I already collected and published some info about 20-30 various valves, just brief descriptions and images, but like I said, I am trying to create quality library where people can find useful informations, that save times for professionals and to students, so I hope that you can help, simply by sharing Your knowledge with me and visitors of my site. Thanks.
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Nov 7, 2009 #2
    Also, I forgot to say in last post, all valves that I listed until now (about 30) You will find in right navigation under 2006/september. When I add some more valves i will create some easier to navigate menu.

    Also link which will take You to page when You can give me suggestin and new info is in top header navigation called "Suggest new valve info " You can't miss :)

    Big thanks in advance to all people who are interested to help.
     
  4. Nov 17, 2009 #3
    Ok, please give some advice or suggestions or small review of this project
     
  5. Nov 17, 2009 #4

    stewartcs

    User Avatar
    Science Advisor

    You'll probably not get much help honestly. Most engineers refer to the OEM of the valve for its characteristics. Can't really hang my hat on an internet user's blog if you know what I mean.

    CS
     
  6. Nov 26, 2009 #5
    Ok,thanks for honest answer :)

    i will try to do this anyway and I hope that i will helpfully at least for students or DIY people.
    Thanks again on honest answer!
     
  7. Nov 26, 2009 #6

    Q_Goest

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Hi solenoid. A really useful valve library that catagorizes not just the various measurable functions of the valve, such as pressure range, temperature range, seal types, materials, etc... but also looks at how well the design is suited to a specific application would be extreamly useful. One of the first jobs I had at my present position was to evaluate various valves for different types of service. Typically, I would get a valve from a supplier and disassemble it, then look at stresses, flow capacities, sealing ability, materials, etc... and compare the valve to a given list of requirements that depended on the service. For flammable service for example, the valve could not be made out of materials that would melt below 1300 F. It also had to have a secondary, metal form of sealing both internal and external. Threaded joints were considered acceptable (such as pipe thread) but Teflon chevron packings in the bonnet would not because they will melt and allow flow through the valve stem. Similarly, the valve seat would have to have a secondary metal to metal seal. A primary seal of elastomer or plastic would be acceptable to provide bubble tight shut off as long as a secondary means of sealing was available, even if that secondary means was not bubble tight. The idea here was to prevent a larger incident in case a flammable system failed and caught fire.

    I was appauled at many of the valves I'd examined. Some valves were underdesigned. Stresses were ridiculously high in some. If I were trying to come up with a web site that reviewed valves such as this, I'd first try and come up with a very specific list of criteria, and not just accept what a supplier provided. I might even have a special catagory for valves that actually had a comprehensive review. So you might catagorize a supplier's valve per their original recommendations, but then also start working on a detailed review of valves. This detailed review would entail the supplier providing a valve for disassembly and analysis. Findings from that review could be made public, though you might need permission of the supplier.
     
  8. Nov 28, 2009 #7

    thanks for useful info from real life.
    You made me think about concept. In my library that I tried to build I categorizing by valve type, but, can You suggest me some other ways which I can use to categorize valves?
     
  9. Nov 29, 2009 #8

    Q_Goest

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Categorizing valves by type (ex: ball, globe, gate, solenoid operated, etc...) is a good way to start, but many valves can be used for the same purpose. A globe valve can be used in applications that will also use a ball valve or gate valve, so for someone in industry trying to select a valve, it can be challenging to determine what will work for a given application.

    We had a database in our company that ended up falling into disuse and was eventually cancelled. The database tried to categorize valves into the various services and also various valve properties such as temperature and pressure range. Someone searching for a valve could search a given pressure range for example, a broad valve type, or on any number of options. I'm assuming the database you envision would have specific categories for pressure range, temperature range, materials of construction, end connections, etc... But you can also categorize by service such as inert, oxidizer, flammable, toxic, etc... Another category would include specific industry tests that the valve passes such as certain flammability standards, MSS, API or ASME standards, etc... The key in my mind is to provide a database that can be searched on by simply inputting some basic parameters such as pressure, temperature, type of service, size, and style of valve, and the database would spit out all valves that met those criteria.

    There is a huge amount of work to creating such a database, so I think you need to consider how you can make it easier to put together. Perhaps solicit valve manufacturers for suggestions on the database first, then put together computer software that allows those manufacturers to essentially categorize their own valves. You would then act primarily as the overseer or caretaker of the web site with valve suppliers doing the leg work to get their valves listed. I could see this working if you worked closely with valve suppliers and they saw a benefit in 'advertising' their valves through your web site by having their valves listed.
     
  10. Nov 29, 2009 #9

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    Building a database such as you're suggesting would also be reinventing the wheel. A site like http://www.globalspec.com/" [Broken] already has a huge database of valves, a filtering search engine to find the specs you want, and links to the manufacturers' websites.
     
    Last edited by a moderator: May 4, 2017
  11. Nov 29, 2009 #10

    Q_Goest

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    hmph... they stole my idea. :devil:
     
    Last edited by a moderator: May 4, 2017
  12. Dec 1, 2009 #11

    stewartcs

    User Avatar
    Science Advisor

    That is appalling!

    Nevertheless, I still take my vendor's data at face value until I'm given a reason not to. It is hardly economical for most companies to reverse engineer a valve to determine if it was design properly. I suppose if it is for a mission critical application it might be warranted, but most of us just use book or vendor values.

    If I was unsure if the data they gave me was correct or if the valve was not designed properly, I would asked for their material certs, test results, and calcs or FEA results and verify it for myself. Alternatively, I'd find another reputable vendor...LOL!

    CS
     
  13. Dec 1, 2009 #12

    stewartcs

    User Avatar
    Science Advisor

    As far as I know GlobalSpec just takes than manufacturers' data at face value too, they don't do testing like Q_Goest suggested the OP do.

    It's just cataloged in a convenient place like you pointed out.

    CS
     
    Last edited by a moderator: May 4, 2017
  14. Dec 1, 2009 #13

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    For "critical" valves, I would probably get one that is certified per a national or international standard, not reverse engineer it. By reverse-engineering it you are taking its certification and any possible liability of its failure on yourself, but if you get a certified unit the supplier takes that liability.
     
  15. Dec 1, 2009 #14

    stewartcs

    User Avatar
    Science Advisor

    So would I...

    CS
     
  16. Dec 1, 2009 #15

    Q_Goest

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    The point wasn't that a company should reverse engineer a valve. That implies manufacturing a copy of the valve.
     
  17. Dec 1, 2009 #16

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    Perhaps "reverse engineer" isn't quite the right phrase. Still, having to do an engineering analysis (such as a stress analysis under pressure) of a critical vendor part is generally poor engineering practice, and puts the blame on you if it fails. It is best practice to buy a part that is certified to operate in the conditions you are looking for, especially in pressure systems.
     
  18. Dec 1, 2009 #17

    Q_Goest

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Hi Mech_Eng,
    There's a lesson I learned that I've found is difficult to get across to other engineers, especially younger ones (not to imply that you're a young engineer, I know you're not). That lesson is that accepting a product for industrial service, whether it's a valve, a pump, or an entire system, on the basis that it is somehow 'certified' by the manufacturer, is dangerous. The company I work for has over 15,000 employees worldwide. They won't purchase valves, machinery, pipe flanges from a third world country, or any product without a thorough review. That's not to say we never do so, but it becomes painfully obvious that many suppliers of 'certified' products haven't gone through sufficient testing and don't have enough field experience with their products to be certain that the product is properly designed for the service it's put into.

    Take for example ASME Code testing of relief valves. The RV manufacturer brings a half dozen valves to a test lab and they pop test them, chart the discharge coefficient and assuming all the paperwork has been submitted properly and inspections of company procedures are approved, the valve gets the ASME stamp of approval. Not to say it's easy, but the valve doesn't need to be tested and shown to withstand repeated openings. Doesn't need to show that it won't have problems with galvanic corrosion, etc... I've seen top of the line RV's fall apart after a few uses. I won't mention manufacturer names, but ASME relief valves that fail after repeated use are not uncommon.

    The same thing goes with just about any industry. There's a manufacturer of valves in the propane industry for example that has a huge market share. This particular manufacturer has a terrible reputation with our company, and we've stopped using most of their products. Yet they are certified by UL, ASME and other industry standards.

    I'm not suggesting that all suppliers are poor suppliers. The vast majority of valve manufacturers make solid stuff. But there's too many valves with various certifications on the market today that are downright dangerous. Evaluating components such as these to ensure they're properly designed doesn't take long, and doesn't make the company that investigates the design liable either. The supplier is still liable. It just reduces the number of bad valves in your system.
     
  19. Dec 1, 2009 #18

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    You bring up a good point, how do you know the certification that the part is within spec is valid? This depends on the design criticality of the part. For a screw holding a cable tie to a wall, it probably doesn't matter; just call out a McMaster screw and you're fine, it isn't safety critical. For a bolt pattern holding a flange on to a 100kJ pressure vessel, you'll want material reports, test reports on the certified fasteners, torque specs (or load indicating washers), redundant load paths, etc. etc.

    It is always a good idea to ask for proof of the certification (certified material test reports, load test reports, etc.) This first of helps prove to the company you mean business, and second of all if there is a hole in their testing you will see it. It's also important that you know what you're asking for when you call out a spec. This means buying the spec, and reading it! If you call it out, you'd better know what you're getting in to!

    It's similar at my company (~2500 employees). For non-safety critical designs, you're open to use most vendors. For safety critical designs like pressure vessels or heavy frameworks, you have to use a company-approved vendor, and our engineering standards require safety notes/calculations and certifications.

    You want to be able to trace original design intent from concept (I'm putting a bolt here to hold this part) to design (it will see this expected load based on my calculations, and will have this safety factor) to the bolt used (material, certified material test report). If the bolt fails and it turns out you incorrectly calculated the load it will see, you're at fault (and probably fired). If you call out a bolt but didn't ask for certified test reports, you're still at fault. If the bolt fails because the company gave you counterfeit ones and falsified test reports, you did your homework and they're screwed.

    Still, you want your design to have a reasonable safety factor to help prevent rare events; an FMEA can help with that too.

    Did they fail safe (as in open)? I don't think the ASME code requires a blowoff valve to survive multiple openings... If the valve opens even once a safety investigation should probably figure out why it happened and make sure it doesn't happen again.

    This goes back to knowing what the spec asks for and means, and accounting for it in your design intent. If your design intent requires that a valve open and close a lot, perhaps another kind of valve should be specified.

    Yes I can see if a company has had multiple QC issues, it would be removed from the qualified vendor list.

    It's good advice to not take someone's word for granted. In most of the stuff I do it isn't practical to try and evaluate the design of a part based on our own engineering standards, there are just too many components in our systems and time is always against us. So instead, we rely on certified test reports on safety-critical items, engineering design standards (multiple checks by multiple engineers), safety factors, and qualified suppliers.

    It is critical to always know exactly what the specification/certification MEANS, and how it affects your design intent. Also have in mind what the trail of accountability is; you don't want your design to fail and kill someone with the trail ending at you...
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Valves library
  1. Valve actuator (Replies: 2)

  2. Force on valve? (Replies: 11)

  3. Valve Type (Replies: 9)

  4. Sizing Needle Valves (Replies: 5)

Loading...