Minutes of video conference April 1st 99:
 -----------------------------------------

 Present: Dave Rahm, Michel lefebvre, Terry Hodges, Roy Langstaff,
          Paul Birney, Paul Poffenberger, Margret Fincke-Keeler

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 Pin Carriers:
 -------------
 Dave Rahm mentioned that the bid packages for the pin carriers
 from PCT and Glasseal have arrived at BNL (and he will mail a
 copy to UVic).
 
 The quote for the full order from Glasseal is as follows:

 Glasseal:  903,693.75  total cost for 625 x 2 parts 
                        (does not include steel)

 (Note: It goes without saying that the numbers from one
        company are not to be mentioned to the other.)


 There is some uncertainty as to how machinable the low inclusion
 steel is, in particular for the thin walls and narrow slots of
 our pin carriers.

 Greg Myers from Glasseal says there should be no trouble machining
 remelted material. Their mother company will do the machining. 
 They work with Inconel and Invar regularly. He said "We'll work it out."

 Terry and Roy pointed out that it would be best to order
 a small sample of it and let the machinists try it out
 to make sure that they can indeed do it. The re-melted low inclusion
 steel has a lower sulfur content and therefore less lubrication.
       
 Dave Rahm said Greg Meyers from Glasseal will visit BNL on April 2.
 Glasseal has "fired" two blank pieces in their factory and equipped
 one of them with two different kinds of pins: Inconel and AISI446.
 
 Roy mentioned that the perpendicularity of the tapped holes was 
 measured at UVic and found to be between 1/2 to 3/4 degrees.
 He pointed out that the clearance of the screws in the tapped
 holes allows for a movement of up to 2 to 3 degress, so he
 figures that there should be no problem as log as the holes are
 machine-drilled and -tapped at the same time.


 Drawings:
 ---------
 Roy pointed out that he cannot put the latest version of any
 drawings onto CDD until the previous version has been approved
 by all that need to approve. (That is a feature of CDD.)
 It was agreed to sort out after Easter which drawings still need
 approval to allow installation of the next update.


 Bellows:
 --------
 John Koehler put some more dimensions on the feedthrough drawings
 and Jake is working on making all the drawings consistent. 
 A bellows with 14 convolutiuons will be calculated next. There is
 some worry that there might not be enough room left at the bottom
 to allow for access of cutters and welders. 
 Dave Rahm measured that there has to be a minimum clearance
 of 3.12" between the bottom of the cold flange and the plate of 
 the cold box to allow room for the pigtail cables.

 At this point in time there is no firm word on the cuffs.
 
 

 Vacuum Cables:
 --------------
 UVic was about to receive 20 cables from Carleton (they arrived).
 Larry Premisler was to fax the spec sheets for the bid package to UVic
 (they arrived also).
 Helio was supposed to obtain a sample vacuum cable from Berg, but
 that had not arrived at the time of the video conference.

 
 Insulation:
 -----------
 Terry reported on some studies of convection heat losses at UVic.
 Lacking any other insulating material at the moment, a 1" thick
 layer of Styrofoam was used on both the warm and the cold flange.
 The pin carriers were shielded with plastic plates to prevent them
 from acting as coling fins. The flange heaters were off during the
 test, and there were no vacuum cables inserted.
 The heat loss by convection at 1 bar was determined to be
 approximately 60W. It was estimated that at 3 bar there would be
 a convection loss of 120W.
 
 Although Styrofoam should not be used for the final approach, 
 the idea was to show that insulating the flanges does have
 a considerable effect.
 Dave Rahm recommended Rohrcell foam as an (expensive) acceptable,
 i.e. non Argon-polluting alternative. 

 
 PRR follow-up:
 --------------
 Pierre Pailler has pointed out to the feedthrough team that 
 the assembly, welding, and testing of the feedthroughs in the
 cryostat has to be done by both the cryostat team and the
 involved feedthrough teams (BNL/UVic).

 
 Slow Controls:
 --------------
 Dave Rahm has raised attention in several Larg meetings that 
 the responsibility for the Slow Controls for the feedthroughs
 should be taken on by the Slow Controls group or the Cryostat team. 



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