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[Gavin Wilks <gwilks3 AT uic.edu>]

Hello All,

I would like to provide an update on the cooling tube status.

After sub-optimal outcomes with the hard and soft tubes, Rahul and Bob were recommended Tygon 2001 plasticizer-free tubing used in PHENIX. Some spare tubing from PHENIX was tested overnight with compressed air at ~61 psi. There was no leakage detected with the soap bubble testing at the tube connection points, but the pressure did drop overnight to ~47 psi. It was discovered that the tubing had expanded from the high air pressure. The tubing is currently being tested with NOVEC at ~25 psi using 12 dummy FST modules with a total of 48 tube connection points (see photos attached). There will be 96 total connection points for the full FST setup.

There are varying types/sizes of clamps being used for the current test due to limited availability (see photos attached). The proper sized clamps need to be identified for the two different sized cooling tube barbs. 

We will remotely monitor the status of the cooling system until Tuesday and physically inspect the system once per day.

Photos: https://drive.google.com/drive/folders/11NNO-CgbmrIxefFT0V41LcunRWVSKGmV?usp=sharing

Best,

Gavin

On May 28, 2021, at 17:10, Xu Sun <sunxuhit AT gmail.com> wrote:

Hi Christian,

I believe we only use one type of clamp to do the test. I am not sure how other clamp will behave.

But Rahul and Bob did the test with multiple set of hose and they all show the similar leak.

Best,

Xu

On Fri, May 28, 2021 at 3:45 PM Videbaek, Christian <cvidebaek AT bnl.gov> wrote:

Hi Xu,

In the video it looks like the leaking part of the tube is below the screw part of the hose clamp.

Is this the case for any other connectors on the test setup?

If so, do any of the other hose clamps (https://drupal.star.bnl.gov/STAR/blog/videbaks/fst-installation) show the same problem?

Thanks,

Christian

---

From: Star-fst-l <star-fst-l-bounces AT lists.bnl.gov> on behalf of Yi Yang <yiyang AT ncku.edu.tw>
Sent: Thursday, May 27, 2021 8:54 PM
To: Xu Sun <sunxuhit AT gmail.com>
Cc: L Star-fst <star-fst-l AT lists.bnl.gov>
Subject: Re: [Star-fst-l] FST cooling tube leak : We might have a solution

 

Hi Xu,

Thanks a lot for the explanation and yes I saw the nice video and picture. 

It is very interesting and strange, it looks to me that it is the problem of the tube itself, not related to how we clamp them, is it right?

Have you contacted the company to ask about this strange issue? In my opinion, t (leaking between the two layers of soft tube) is not right for any hose. 

Could you please also remind me that these softer tubes in the video are irradiated ones or the new ones? Thanks a lot.

Cheers,

Yi

+++++++++++++++++++++++++++++++++++++++++++++++++++
Yi Yang, Associate Professor
Department of Physics
National Cheng Kung University
Tainan, 701 Taiwan
E-Mail: yiyang AT ncku.edu.tw
Tel: +886-6-2757575 ext.65237
Fax: +886-6-2747995
Group Web: http://phys.ncku.edu.tw/~yiyang
+++++++++++++++++++++++++++++++++++++++++++++++++++

On Fri, May 28, 2021 at 6:51 AM Xu Sun <sunxuhit AT gmail.com> wrote:

Hi Yi,

We did not try the Teflon tape since Rahul had some concerns. I couldn't recall the exact concern from Rahul, but will let you know once I figure it out.

For the leaking, it is actually between the two layers of soft tube, not between the soft tube and stainless steel tube.

Please find the details in the following link: https://drive.google.com/drive/folders/1C6eSbNqVj1qaO5SXHc-sCi1dlO3qNIU1?usp=sharing

It seems like a general issue of the soft tube (even though we didn't test every tube with soap).

Best,

Xu

On Thu, May 27, 2021 at 6:17 PM Yi Yang <yiyang AT ncku.edu.tw> wrote:

Hi Xu, and all,

Thanks a lot.

I am wondering if you guys tried to wrap some Teflon tape in the pink region before putting the tube on (this is what I mentioned in the other email). It might be worth to try (?).

Also, (probably you talked about this during the meeting already) could you please tell me if this leaking issue is general for all tubes or just for some particular ones? Thanks a lot.

Cheers,

Yi

Xu Sun <sunxuhit AT gmail.com>於 2021年5月28日 週五，上午5:46寫道：

Hi Gerard,

Thanks for the picture. Maybe Rahul/Bob is a better person to comment on this.

But as far as I learnt from Rahul, in the pink region, there is nothing to clamp on. A flat surface with clamp will not create a sealing surface to stop the leak.

For the blue region, the only barb is also not perfect for sealing. That's why we have to find a second place to put clamps on. And the red region is the only possible place.

Best,

Xu

On Thu, May 27, 2021 at 5:34 PM Visser, Gerard <gvisser AT indiana.edu> wrote:

Don't you think the "barb" is meant to have an tubing with ID which is a _close_ fit over the region I marked in pink here, and have clamp(s) over the region I marked in blue?

<Untitled2.png>

Riding up over the region I marked in red looks like a recipe for leaking,

But, like I said, it is hard to judge from afar and I certainly must defer to you guys. I don't want to generate a big long discussion if it doesn't help anyways.

And yeah this "barb" is kind of unusual in design and I can believe it may be hard to deal with.

I am sure you guys will converge on the proper solution.

     - Gerard

---

From: Xu Sun <sunxuhit AT gmail.com>
Sent: Thursday, May 27, 2021 5:15 PM
To: Visser, Gerard <gvisser AT indiana.edu>
Cc: L Star-fst <star-fst-l AT lists.bnl.gov>
Subject: Re: [Star-fst-l] FST cooling tube leak : We might have a solution

 

Hi Gerard,

> By the way, all this cooling business is not my worry but in these pictures including the latest it _appears_ that the tubing is inserted too far over the "hose barb" on module.

This is because that "hose barb" is the only place we could put clamps on except the barb in the front of the stainless steel tube.

There is no other place on the cooling tube that can be clamped on and crates a good sealing. 

Best,

Xu

On Thu, May 27, 2021 at 5:08 PM Visser, Gerard <gvisser AT indiana.edu> wrote:

Maybe. I don't know, not a judgement I can make. It sounds better to use a novec-resistant tubing.

By the way, all this cooling business is not my worry but in these pictures including the latest it _appears_ that the tubing is inserted too far over the "hose barb" on module. I don't understand why it would be done like that and it looks wrong to me, But it is hard to really judge from afar.

     Gerard

---

From: Xu Sun <sunxuhit AT gmail.com>
Sent: Thursday, May 27, 2021 5:03 PM
To: Visser, Gerard <gvisser AT indiana.edu>
Cc: L Star-fst <star-fst-l AT lists.bnl.gov>
Subject: Re: [Star-fst-l] FST cooling tube leak : We might have a solution

 

Hi Gerard,

That's a good question, but I don't have any answer right now.

We will need to see how the test goes and also need input from Rahul and Bob.

But it was used in PHENIX for some time, maybe it's fine?

Best,

Xu

On Thu, May 27, 2021 at 4:57 PM Visser, Gerard <gvisser AT indiana.edu> wrote:

hi Xu,

   In such case, don't we have to worry about the resulting contamination "plating out" elsewhere in the system and causing trouble?

    Gerard

---

From: Star-fst-l <star-fst-l-bounces AT lists.bnl.gov> on behalf of Xu Sun <sunxuhit AT gmail.com>
Sent: Thursday, May 27, 2021 4:51 PM
To: videbaek <videbaek AT bnl.gov>
Cc: Star-fst L <star-fst-l AT lists.bnl.gov>
Subject: Re: [Star-fst-l] FST cooling tube leak : We might have a solution

 

Hi Flemming,

Bob and Rahul told us the novec will eat up the materials and the leaking rate will increase with time.

Best,

Xu

On Thu, May 27, 2021 at 4:48 PM videbaek <videbaek AT bnl.gov> wrote:

Hi

Did Rob indicate the rationale for exchange every year. Possible Rad
damage ?
It would be good to know.

best F.


On 2021-05-27 16:37, Zhenyu Ye wrote:
> This is good news, indeed.
>
> If it works, it would solve our problem for the upcoming Run.
> But it also brings a new potential issue, that we need to replace the
> cooling tubes every year.
> If we can avoid it, it will be the best.
>
> Zhenyu
>
>> On May 27, 2021, at 2:33 PM, Tribedy, Prithwish <ptribedy AT bnl.gov>
>> wrote:
>>
>> Hello everyone,
>> We have good news to share with you. With a new kind of tube that was
>> previously used by Phenix, we might have a solution to our leak
>> problem. We need to do more tests, but I think this is a good
>> progress.
>>
>> Remember we had the following issues:
>>      • The hard tubes were very stiff, bending radius was large but had
>> less leak.
>>      • The soft tubes had major leaks between layers.
>> A solution came after Bob/Rahul contacted Robert Pisani from Phenix.
>> From them we got this third type: Tygon 2001 plasticizer free" tubes.
>>
>> With our pressurized air setup, we see NO LEAKS. No more bubbles with
>> soap.
>>
>> Also, it's much cheaper. It costs like $2.5 c per ft (compared to
>> $20-80 for the previous soft tube we were using).
>> According to PHENIX experts, they should be replaced once every year
>> -- I think that is feasible.
>>
>> So, we'll get 25 ft of these tubes tomorrow and this way we have the
>> full weekend to do the testing.
>> If things look good in next couple of days and no leaks are found‚ WE
>> MIGHT HAVE A SOLUTION.
>>
>> We will keep you updated.
>> Best,
>> Yu, Xu and Prithwish

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--

+++++++++++++++++++++++++++++++++++++++++++++++++++
Yi Yang, Associate Professor
Department of Physics
National Cheng Kung University
Tainan, 701 Taiwan
E-Mail: yiyang AT ncku.edu.tw
Tel: +886-6-2757575 ext.65237
Fax: +886-6-2747995
Group Web: http://phys.ncku.edu.tw/~yiyang
+++++++++++++++++++++++++++++++++++++++++++++++++++

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