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Ultrasonic Sciences Ltd
We specialize in the design and manufacture of automated and semi-automated ultrasonic testing systems, including multi axis, multi channels systems and phased array electronics.

3246 views
03:48 Apr-18-2002

Dent McIntyre

Consultant, NDE Manager NDELevel III/3
NDT Consultant,
Canada,
Joined Nov 1998
246
Vacuum Box Testing

Can someone please tell me what kind of pump is used for Vacuum Box Testing? How about an Industrial Vacuum Cleaner?
Who sells the Vacuum Boxes?
Thanks for any guidance on this.


 
09:49 Apr-21-2002

V K Dilip

Consultant
Industrial Support Services,
Saudi Arabia,
Joined Jan 2001
8
Re: Vacuum Box Testing : Can someone please tell me what kind of pump is used for Vacuum Box Testing? How about an Industrial Vacuum Cleaner?
: Who sells the Vacuum Boxes?
: Thanks for any guidance on this.
.

For this test you dont need a vacuum pump, most vacuum boxes operate on Compressed Air (Yes). And compressed air is usually available on most Sites. You need a vacuum pump only if the Site you are working does not have compressed air supply.
The equipment is not expensive and should be available with most NDT suppliers/stockists



 
07:00 May-03-2002
Jim Knowles
Re: Vacuum Box Testing : Can someone please tell me what kind of pump is used for Vacuum Box Testing? How about an Industrial Vacuum Cleaner?
: Who sells the Vacuum Boxes?
: Thanks for any guidance on this.
.Vacuum Box Testing.
The equipment depends on the test criteria.
Usually we use a small rotary oil pump to pull down to -500 millibar pressure (half atmosphere).
Thus giving a good differential pressure to ensure moisture or DPI is not trapped in the through leakage area.
Leakage rates are generally quoted for the vacuum box technique at -500 mbar as being in the region of 1 x10-3/1x10-4 mbar litres.(Nuclear Applications)
Vacuum boxes can be made up very easily especially where sppecial shapes are required to fit over the test area or weld. Generally made from 8-10mm thick perspex sheet, glued and sometimes drilled and tapped together. The open side covering the test area usually has a foam seal to allow sealing from the outside atmosphere when the vacuum is applied.
Test liquid is 5-10% solution ofTepol (Liquid Soap) to show the leakage area.

Regards
Jim Knowles



 
06:07 Jun-07-2002
Mark Fulton
Re: Vacuum Box Testing : Can someone please tell me what kind of pump is used for Vacuum Box Testing? How about an Industrial Vacuum Cleaner?
: Who sells the Vacuum Boxes?
: Thanks for any guidance on this.
.We do vacuum box testing on heat exchanger bundles and have had great success using air driven venturi pumps for our vacuum source. The vacuum boxes are made out of clear cast acrylic sheets which are shaped for the particular application. Our largest to date is 24" x 36", we used 2" thick material for these and had no real flex in them. On a 24x24 size with a full radiused side, we used 1" thick and did notice flexing if the vacuum was applied too quickly, it wasn't detrimental to the test. It's also important to use closed cell foam for your sealing gaskets, we use 1" thick foam around the edges which allows a generous amount of compression to seal on uneven surfaces. I have some photos of our process which I can send if you would like.McMaster Carr is a good source for all of the materials used.



 
07:08 Jun-07-2002
Jim Knowles
Re: Vacuum Box Testing : : Can someone please tell me what kind of pump is used for Vacuum Box Testing? How about an Industrial Vacuum Cleaner?
: : Who sells the Vacuum Boxes?
: : Thanks for any guidance on this.
: .We do vacuum box testing on heat exchanger bundles and have had great success using air driven venturi pumps for our vacuum source. The vacuum boxes are made out of clear cast acrylic sheets which are shaped for the particular application. Our largest to date is 24" x 36", we used 2" thick material for these and had no real flex in them. On a 24x24 size with a full radiused side, we used 1" thick and did notice flexing if the vacuum was applied too quickly, it wasn't detrimental to the test. It's also important to use closed cell foam for your sealing gaskets, we use 1" thick foam around the edges which allows a generous amount of compression to seal on uneven surfaces. I have some photos of our process which I can send if you would like.McMaster Carr is a good source for all of the materials used.
.
The ASNT Non Destructive Testing Handbook Volume One "Leak Testing" Part 4 is an excellent source of information on the variety of box shapes and cross sections for difficult geometries.
Regarding vacuum pumps, simple iol rotary pumps regulated to half an atmosphere or 500 mbar will provide sufficient vacuum for the test.
Size of the pump is imprtant especially of you are evacuating a large volume.
Pumps are avaialble from Leybold or Edwards vacuum comonents.



 
05:13 Aug-30-2002
Dr. K.A. Danso
Re: Vacuum Box Testing : Can someone please tell me what kind of pump is used for Vacuum Box Testing? How about an Industrial Vacuum Cleaner?
: Who sells the Vacuum Boxes?
: Thanks for any guidance on this.
.I shall be very pleased if send me information about how vacuum box for the inspection of the bottom plates of oil storage tanks can be designeg and constructed.
Thank you for the assistance.



 
16:28 Sep-09-2013
omar
Re: Vacuum Box Testing In Reply to Dent McIntyre at 03:48 Apr-18-2002 (Opening).

check this site http://www.silverwingndt.com/vacuum-box/v750-vacuum-box-bubble-leak-testing.aspx

 
11:34 Sep-10-2013

collin maloney

NDT Inspector, - Plant Inspector
Applus RTD,
Australia,
Joined Nov 2000
147
Re: Vacuum Box Testing In Reply to Dent McIntyre at 03:48 Apr-18-2002 (Opening).

Hi Dent, why use a pump at all. Most sites have either compressed air available by pipe or a compressor. Just hook up your hose with a venturi to the box and fit the box with a vacuum guage to confirm setting.
You can make your own box's with thick perspex and rubber door seals if you want to save money, otherwise silverwing etc will be more than happy to take the cash.
Cheers
Collin

 


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