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!

*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.

Jobs

xPost from Pharma: Sanitary Clamp Replacement

xPost from Pharma: Sanitary Clamp Replacement

(OP)
This is an xPost from the Pharma thread since the forum looks pretty dead. I appreciate your help!

Hi All,

I have been tasked to head a project to reduce the risk of contamination in our bio-pharma production facility. The main goal is to roll out the use of torque wrenches to use on sanitary wing-nut triclamps. I have been asked to replace the sanitary clamps on all of our bioreactors (nearly all clamps from 2003). This would be the replacement of >2500 low pressure wing-nut tri-clamps. I have already replaced the clamps on 2 bioreactors and I'm starting to wonder if this activity is really worth it?

Is it best practice to replace the clamps after some time? Granted, some clamps are so old they have residue on the inside of them, but do the clamps, wingnuts, or threads loose their integrity after a time?

Thanks!

RE: xPost from Pharma: Sanitary Clamp Replacement

That depends their usage; certainly, there will be wear and tear on the threads through constant usage. But that's pretty much it, unless you're managing to overstress the clamp itself.

From a cleanliness perspective, they probably should be replaced; there have been incidences of contamination within sterilization chambers in hospitals.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: xPost from Pharma: Sanitary Clamp Replacement

Are all of your flanges and clamps of the same brand? If not then that is the first issue.
It would be straightforward to build a gauge to check the clamps.
I have seen wear on the clamp surface and I have seen hinge pin wear that both impact clamping.
You also have to have very tight control on the seals. If they are too hard or too soft they will not fill the gap properly.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: xPost from Pharma: Sanitary Clamp Replacement

(OP)
It would be near impossible to determine where the clamp ferrules were sourced from as we have many different skid providers. The clamps are from a few different vendors, but mostly Alfa Laval. Torque wrenches have not been used on these clamps to date so I couldn't imagine they have been overstressed.

They are probably 15 years old. Would that wear and tear on the threads cause inaccurate torqueing of the clamp (excluding galled threads)?

How would you describe the impact to clamping effectiveness of an old clamp? Is it that the distributed forces become uneven?

RE: xPost from Pharma: Sanitary Clamp Replacement

Perhaps we should back up a bit. Please explain what the clamps are supposed to be doing and what the torque wrenches are supposed to do.

How old are the seals?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: xPost from Pharma: Sanitary Clamp Replacement

When I worked at a vaccine filling site clamps were replaced for aesthetic reasons (why give something to an auditor to nitpick). It could be the result of the clamp looking beat up (from being dropped, rubbed against other metal pieces), tarnished from the cleaning and sterilization cycles, etc. I was not aware of a program to track clamp life because of lifetime concerns.

The contamination risk really depends on how careful the operators are when assembling and disassembling and if their training on the matter was sufficient. I'm sure you know that you can't just wave sanitized components around higgly-piggly and expect things to stay clean. It will be imperative that the torque wrench be kept clean and possibly sterilized regularly if it's going to be used on sterile status items.

RE: xPost from Pharma: Sanitary Clamp Replacement

What does the manufacturer say? I do not have a lot of experience with these fittings but they appear to be very reliable and robust, and I have never heard of any issue with them. I do not see that torque wrenches would improve things.

RE: xPost from Pharma: Sanitary Clamp Replacement

Not all of the makers use the same dimensions, and some bias tolerances to one side or the other.
I have seen some combination that simply are not reliable together.
If the clamps and flanges are not a good match then torque will not be a reliable indicator of suitable clamping. You really should test some and measure the actual gap between the flanges, that is the critical dimension. If you have consistent components then torques is a good measure.
If you haven't been using torque wrenches I would assume that they are being seriously over-tightened.
I have seen plants where all clamps and flanges have mfg marks on them, and the clamps have mo-yr stamped into them. As the become older (if they are used a lot) the inside surfaces can become worn changing the way that they mate to the flanges. I have seen them worn to the point of bottoming out and not applying enough clamp force, or clamping unevenly.

With seals some will become hard with age, and some soft. Depends on the specific compound and the service conditions.
Either way and you get a seal that traps materials and is hard to clean.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: xPost from Pharma: Sanitary Clamp Replacement

Have you contacted the manufacturer of the clamps and asked for their recommendations?

RE: xPost from Pharma: Sanitary Clamp Replacement

If you see residues (of the product, I suppose) in the clamp groove, there is misalignment of TC ferrules. This is a bigger problem than clamps losing their integrity. The major failure factor for clamps is damage of threads. Replacing all clamps at once doesn't add any value unless all are rusting.

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

eBook: Product Innovation Platform Assessment
Over the past few years, there has been growing interest among industrial companies and solutions providers with regards to Product Innovation Platforms, where design, manufacturing and IoT tools are bundled into a single software package. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close