×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Quick Open Cover

Quick Open Cover

Quick Open Cover

(OP)
I am developing a project to "Quick Open Cover" and would like to know which standard to follow or even a book. There's something written in ASME? Will be mounted on a simplex filter with 3.5 MPa of pressure and temperature of 200 ° C, Filter Material: ASTM A 351 CF8 (Cast).
Please help me.
 

RE: Quick Open Cover

gilsonnb, I would start by determining whether the work is to comply with a Code or Standard, and if so, which one. There may be some guidance contained therein.

Then, I would search the internet for various manufacturers products, to get some knowledge of the various styles available.

You could maybe just buy one.

Regards,

Mike

 

RE: Quick Open Cover

Unless you are a manufacturer yourself looking to develop a new product line, there are lots of these on the market and it would be quicker, easier and cheaper to just buy one rather than trying to develop something for one time use.

In general, most of the ones I've seen have been designed to ASME Section VIII Div 1.

RE: Quick Open Cover

(OP)
Yes, I am developing a product line. We are following the ASME SECTION VIII DIV.1 , But the standard only says about flat head , I wonder if there is a standard for the mechanisms of head.

RE: Quick Open Cover

So since you're following Section VIII Div. 1 you have read Appendix FF and do not feel that it provides sufficient guidance for you to design to?

jt

RE: Quick Open Cover

I do not read UG-35.2 at all as applying only to flat heads.

If I were developing a product line I would definitely buy a few types...

Regards,

Mike

RE: Quick Open Cover

(OP)
Appendix FF UG and paragraph 35.2 is not itself sufficient information to design. But I thank everyone for their patience and attention. I'll see if I can find another way to calculate, design ...

Thank you very much
 

RE: Quick Open Cover

Well, there is always trial and error and UG-101 burst tests ... but probably not the most efficient way to start smile

RE: Quick Open Cover

Let's not forget the Foreword, U-1(a)(3), and U-2(g).

jt

RE: Quick Open Cover

gilsonnb, I have not, and doubt I will ever design one of these closures, but I imagine the following:

The Code has sufficient rules to design the primary pressure retaining portions of the closure, I probably would not have any qualms about taking that part on. The basic mechanisms I also imagine to be relatively simple.

BUT I imagine the real guts of a true quick opening closure to be the safety and interlock systems. This is where, to my mind, the real "art" is involved. I expect these systems to be proprietary to a large extent, I doubt you will find design rules for them.

Interesting project, good luck.

Mike

 

RE: Quick Open Cover

I hate to be the party pooper but the conditions you state are going to require someone well versed in the art and science of PV design.  Your temperatures are out limits of most materials for an O-ring seal.  You haven't stated the diameter butthe highest pressure I've seen is around 300 psi for 18" dia t-bolt closure, and this was using an O-ring at 100°C.  Your pressure is too high for a hinged bar closure. This doesn't leave many choices other than a bolted or screwed head and the exotics like a form of a breech lock or interrupted screw.  

RE: Quick Open Cover

Some familiar with the ASME indexing sytem may be able to give you the title to this code book

http://files.asme.org/Catalog/Codes/PrintBook/13833.pdf

4.8.1 Scope...........................................4-166
4.8.2 Definitions ..................................4-166
4.8.3 General Design Requirements .......................................4-166
4.8.4 Specific Design Requirements........................................4-167
4.8.5 Alternative Designs for Manually Operated Closures ................4-167
4.8.6 Supplementary Requirements for Quick-Actuating     

(Quick-Opening) Closures   ....................................... .4-167
 

RE: Quick Open Cover

unclesyd

That is the new ASME VIII Div 2 table of contents.  

RE: Quick Open Cover

Canadieng

Thanks for the information.

Part of the answer to the OP's question should be there.  

RE: Quick Open Cover

I believe that gilsonnb is looking for explicit calculations that can be used verbatim - the "Quick Acting" chapters of VIII-2 are more vague/abstract.  For example:

4.8.4.4 It is recognized that it is impractical to write requirements to cover the multiplicity of devices used
for quick access, or to prevent negligent operation or the circumventing of safety devices. Any device or
devices that will provide the safeguards broadly described in paragraphs 4.8.4.1.a, 4.8.4.1.b and 4.8.4.1.c
above will meet the intent of this Division.

RE: Quick Open Cover

also quoted from VIII-2 Annex 4.B "Guide for the Design and Operation of Quick-Actuating (Quick-Opening) Closures (Informative)":

4.B.3 Design
4.B.3.1
Code rules cannot be written to address each specific design; therefore, engineering judgment
exercised by a qualified designer with the necessary experience is required to achieve a safe design.
Because of the multiple requirements imposed on the design, it should be prepared by a designer with suitable
experience and training in the design of quick-actuating closures.

RE: Quick Open Cover

(OP)
Personal

Thank you for answers.

Unclesyd,
The range of work is the same, this is a filter 2", 3.5 MPa, 200 ° C, as B16.5, Material: 351 CF8, the thickness of the filter was calculated to meet these conditions.

As you said, I'm really looking for something simpler, ASME SECTION VIII DIV. 2 It is very vague. But give a look. Did not anyone have any picture, or some link, for me to see it to follow the?

Thanks.

RE: Quick Open Cover

Is the 2" dimension the actual OD?

Some possibility is to use a metal seated union design with blind side or a 2 bolt clamp flange or an acme or buttress thread threaded cap.
 

RE: Quick Open Cover

You state that your design code is ASME so you can use ASME 31.xxx fittings.  

Here are two approaches mentioned in my previous post.   Your environmental conditions take you out of the O-ring sealing range, which limits you to a metal to metal or a metal gasket configuration.
Your conditions also put you out of range of sanitary type clamping connections.
I think the Gandl Fittings would be your best approach by using a welding union with plug instead of the tail piece.
You could make the nut of different material to help alleviate galling.
The second site has screwed type quick opening head

http://www.gandlfittings.com/unions.htm?kc=5Qny8hFUZc75TItn6WcMM4EEoqFBiEJUAxr9OmYT#

http://www.islipflowcontrols.com/images/products/brochures/fabricated/FabStrainers_cat_21-22.pdf

 

RE: Quick Open Cover

Your small diameter is good and bad it precludes certain approaches but makes some others possible.
The one thing that prevents you from using a yoke type closure is they require the use of an O-ring to seal and your specified temperature  takes you out the O-ring territory.  With your small diameter a yoke would be no problem pressure wise if there is some type self-energized metal gasket that one could used.

The reason I suggested the metal seated pipe union is that it readily available and allowable code wise.  To me it allows you use a nut of different material and any type lubricant to alleviate potential galling problems with a screwed connection on SS.

It would be possible to use the seat design of the union thread piece, either the metal to metal or the O-ring seal  design with a pressure energized metal O-ring and closure using the  union blank cap.  The closure force could then be applied by a yoke and screw instead of the union nut.  There are several possibilities to mount the yoke, trunnions , split clamp, welded lugs on the filter body, screwed collar using the threads on the union thread piece.        

Even the yoke clamp here depends on O-rings to seal so the temperature is limited by the O-ring compatibility with the process fluid.  Pressure is to Class 1500.  

http://www.islipflowcontrols.com/images/products/brochures/fabricated/FabStrainers_cat_21-22.pdf

RE: Quick Open Cover

Here is another possibility for a gasket with a metal to metal connection in place of an metal O-ring.
You might want to look at the Selco Gasket it is blowout proof and fire safe.

http://www.selcoseal.com/
 

RE: Quick Open Cover

All kinds of metal / graphjite gaskets available, if a conventional gasket can be used. See Flexitallic, Garlock, etc.

Regards,

Mike

RE: Quick Open Cover

The style of quick opening closure that you are looking is frequently refered to as being the 'bridge type' and cannot be made to fully meet the intent of UG-35. Development of design formulas etc per code are difficult to produce and, with the length of time that these closures have been around, that the original designs were based on some type of proof testing criteria such as a lime was proof test.
A 200 deg C design temp is not an issue, Viton A seals are rated for continous operation at 204 deg C and you have other options such as Aflas.

RE: Quick Open Cover

I do not see aproblem designing a 2" filter w/quick clossure as defined in the samples.
  The cyl and plate can possible be calculated but the bolting/closure may not and proof will be needed.

1- you do not need ASME stamp for it.
2 if ASME VIII-1 stamp needed: you should have it Proof tested, all materials have to comply w/the Code.
other: have the design cert by a proffessional eng experienced i  the design and stamp it with ASME div2.
 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources