Hi Roberto,
Jim Mills and I were discussing the pressure force during lunch
time.
> The vacuum pressure differential is 15 psi so 4x10
=400 in2 . Foot print area.
But I guess (foot print) 4x10 = 40 in^2, not 400 in^2 =>
vacuum force = 40 in^2 *15 psi = 600 pounds, right ?! Not 6000
pounds.
But didn't we do pressure test up to 6 bar ~ 87 psi before the
low-field test => 87*40 = 3480 pounds.
But I agree that avoiding stepping on the solenoid too often
couldn't be a bad thing :-)
Kin
On 07/10/2017 05:47 PM, Than, Yatming
(Roberto) wrote:
The vacuum pressure differential is 15 psi so 4x10 =400 in2
. Foot print area.
So vacuum force is 6000 pounds.
Compared to 150 pounds.
Roberto
Kin,
To be on the safe side I suggest that we keep the traffic
through the
solenoid itself to the bare minimum. Put up a ladder on
the lead side.
Ed
On 7/10/2017 5:32 PM, Kin Yip
wrote:
Hi,
> lead end platform by going up and over the lead
end steel instead of by walking across the superconducting
magnet.
As of right now, there is nothing for you to go/climb up the
Lead-End steel. We need a ladder. We do have a ladder and
scissor lift ...
To go to the lead-end from the inside, you have to either go
through the center of the solenoid or go along the two very
narrow sideways (between the Cryostat
and the steel box). Placing my body sideway, I can
penetrate this side path but kind of barely. So, people
have been walking over the solenoid all the time.
Maybe, we should try to persuade people from doing so and
put up the ladder on the lead-end side.
Kin
On 07/10/2017 04:33 PM, Anerella,
Michael D wrote:
John, Kin, All,
We haven't ever analyzed the allowable load, since there shouldn't ever be any. I don't see why personnel and large tools don't make their way to the lead end platform by going up and over the lead end steel instead of by walking across the superconducting magnet. Even if there is no structural damage, there could be some deleterious effect on the old bolted O-ring vacuum seals. Unlikely, but why take unnecessary risks?
p.s. No surprise regarding John's reply below, given his infamous photo standing inside the magnet, celebrating its transfer to BNL...
cheers,
Mike
-----Original Message-----
From: sPHENIX-magnet-l [mailto:sphenix-magnet-l-bounces AT lists.bnl.gov] On Behalf Of John Haggerty
Sent: Monday, July 10, 2017 3:19 PM
To: sphenix-magnet-l AT lists.bnl.gov
Subject: Re: [Sphenix-magnet-l] Is it OK to stand inside the solenoid ?
Kin,
I don't know for sure; I think the drawings say the inner wall is 10 mm
5083 aluminum, but at SLAC they lifted the solenoid with a spider that fit inside the cryostat like this:
http://www-project.slac.stanford.edu/slacpix/BaBar/16_mag/to_290.jpg
so I always assumed that it wasn't a problem if a couple of people threw their weight around.
sPHENIX itself does not intend to put any load on the cryostat inner wall as far as I know.
On 7/10/17 1:28 PM, Yip, Kin wrote:
Dear Mike, Paul, Jon & Dave,
As Paul Orfin asked below, I sometimes wonder about this too when I
saw people walk through the solenoid.
Can we safely walk and stand inside the inner solenoid ?
Approximately how much weight can the inner solenoid handle ?
/Sent from my Verizon LG Smartphone/
------ Original message------
*From: *Orfin, Paul
*Date: *Mon, Jul 10, 2017 12:37
*To: *Yip, Kin;
*Cc: *
*Subject:*RE: Sonny and Joe have taken the half-rack ... waiting for
the survey result ... carpenter putting up the railing
Kin,
Has anyone determined the maximum load allowed on the inner diameter
of the solenoid? I don't know the details of the inner plate
thickness but there may be a weight limit for materials being brought
in by foot. I just want to make sure there is no damage to the
solenoid. I understand that the magnet was built to handle large
magnetic forces but concentrated loads from someone's foot for
instance, may not have been taken into design consideration. Looking
at the pictures of people in the magnet made me think of this just now.
Thank you,
Paul Orfin
Cryogenic Systems, Collider-Accelerator Department Brookhaven National
Laboratory
Telephone: (631) 344-2899
*From:*sPHENIX-magnet-l
[mailto:sphenix-magnet-l-bounces AT lists.bnl.gov]
*On Behalf Of *Yip, Kin
*Sent:* Monday, July 10, 2017 11:50 AM
*To:* sphenix-magnet-l AT lists.bnl.gov
*Subject:* [Sphenix-magnet-l] Sonny and Joe have taken the half-rack ...
waiting for the survey result ... carpenter putting up the railing
Hi,
45 minutes ago or so, I showed Sonny Simaiuta and Joe Dambra where the
half-rack was in Bldg. 912. They have taken it to Superconducting
Magnet
Division to make small modification.
I've just taken another picture this morning around the Magnet/steel box :
https://collab.external.bnl.gov/sites/sPHENIX-Magnet/Pictures/High%20F
ield%20Test/Return%20Yoke%20Construction/2017-7-10.jpg
Apparently, the survey was taken late last Friday after the magnet was
slightly rotated. Now, we're waiting for the survey group to analyze
the data. Matt (who has been doing the analysis) is out today and
Frank Karl is trying to see whether he can do the analysis or they
have to wait
for Matt to come back tomorrow.
Richard Meier was moving his cables. I also saw that a carpenter was
installing the railing for the platform (all in Aluminium) in the Lead-End.
So, the schedule that D. Phillips sent last Friday (below) seems to
be materializing (though Dave is not here today). Hopefully, the
riggers and Ray Ceruti's group can install the Extension this Wed.
Kin
*From:* Phillips, David B
*Sent:* Friday, July 07, 2017 11:45 AM
*To:* Ceruti, Raymond B <rayc AT bnl.gov <mailto:rayc AT bnl.gov>>; Yip, Kin
<kinyip AT bnl.gov <mailto:kinyip AT bnl.gov>>; Mills, James A
<mills AT bnl.gov <mailto:mills AT bnl.gov>>; Hock, Jonathan <jhock AT bnl.gov
<mailto:jhock AT bnl.gov>>; Streckenbach, Brian <bstreckenbach AT bnl.gov
<mailto:bstreckenbach AT bnl.gov>>
*Cc:* Kobasiuk, Frederick D <kobasiuk AT bnl.gov
<mailto:kobasiuk AT bnl.gov>>; Folz, Charles <cfolz AT bnl.gov
<mailto:cfolz AT bnl.gov>>; Anerella, Michael D <mda AT bnl.gov
<mailto:mda AT bnl.gov>>; Karl, Francis X <karl AT bnl.gov
<mailto:karl AT bnl.gov>>; Ilardo, Matthew <milardo AT bnl.gov
<mailto:milardo AT bnl.gov>>
*Subject:* sPHENIX Magnet plan for next week
sPHENIX Magnet plan for next week:
Friday 7/7 - Riggers place cryostat in correct position
Friday 7/7-Monday 7/10 - Survey confirms cryostat is correctly
positioned
Monday 7/10-Tuesday 7/11 - Carpenters install handrails and access
ladder to internal Lead End platform.
Wednesday 7/12 - Riggers and Magnet Division install Valve Box
Extension
Monday 7/10 - until completed - Drilling/taping holes in return steel
Thursday 7/13 - until completed - Riggers install return steel (this
needs to be coordinated with MD Teck's working on Dog House
connections)
Week of 7/17:
-MD Teck's continue with Dog House connections
-Riggers install Return Steel and shield blocks for Valve Box Platform
-Carpenters assemble scaffolding for access to External Dog House
-Carpenters install handrails etc for Valve Box Platform
David Phillips
Building 911B
Upton, NY 11973
631-344-4671, Fax 631-344-5954, Cell 631-804-9477
On site pager 344-3456 then 4267 then your number
_______________________________________________
sPHENIX-magnet-l mailing list
sPHENIX-magnet-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/sphenix-magnet-l
--
John Haggerty
email: haggerty AT bnl.gov
cell: 631 741 3358
_______________________________________________
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sPHENIX-magnet-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/sphenix-magnet-l
_______________________________________________
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sPHENIX-magnet-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/sphenix-magnet-l
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