[labnetwork] Backing Vacuum Pump - Dry pumps vs Oil Pumps

[Brent Gila]

Hello Pradeep,

We use mostly dry pumps but the few wet pumps we have we use a Fomblin 
type oil and soft start vacuum valves like this one from VAT 
(http://www.vatvalve.com/business/valves/catalog/H/311_1_A).  The soft 
start valve helps to minimize the rush of oil back streaming when 
pumping down chambers from atmosphere and is a little more gentler on 
pumps.  We have not seen an effect in ultimate pressure, but pump down 
times are extended due to the added restriction in the conductance.

I highly recommend a dry roughing pump on the cryopump for 
regenerating.  The 15K charcoal array in the cryo pump can absorb pump 
oil and decrease the cryo pump efficiency over time, which will increase 
the frequency for regens and increase down time.

Best Regards,
Brent
-- 
Brent P. Gila, PhD.
Director, Nanoscale Research Facility
1041 Center Drive
University of Florida
Gainesville, Florida 32611
Tel:352-273-2245
Fax:352-846-2877
email:bgila at ufl.edu



On 11/4/2019 5:39 AM, April, Mark R. wrote:
> *[External Email]*
>
> Good Morning
>
> I only use Dry pumps in my clean room at    Draper.
>
> I removed all of the oil pumps several years ago
>
> Thanks
>
> *Mark R. April*
>
> https://intranet.draper.com/pcweb/media/branding/images/logo_styles/color_logo.jpg
> Senior Equipment Engineer
>
> Microfabrication Laboratory Lead
> /555 Technology Square/
>
> /Cambridge, MA  02139/
>
> /mapril at draper.com <mailto:mapril at draper.com> /
>
> /O # 617-258-1613 C # 617-455-1596/
>
> /www.draper.com 
> <https://urldefense.proofpoint.com/v2/url?u=http-3A__www.draper.com_&d=DwMGaQ&c=sJ6xIWYx-zLMB3EPkvcnVg&r=gl_2fLZA_-_JfH_dOmx7ug&m=r5rIOAO6mwwu499DOGlm3KInSe3pP9iF64SaEDshfYA&s=U7_XM5G7vQHo7qxnxkDRKLkxbuLtXxJLeyVB6n0UjUk&e=>/
>
> *From:*labnetwork-bounces at mtl.mit.edu <labnetwork-bounces at mtl.mit.edu> 
> *On Behalf Of *Pradeep Nyaupane
> *Sent:* Sunday, November 3, 2019 8:21 AM
> *To:* labnetwork at mtl.mit.edu
> *Subject:* [labnetwork] Backing Vacuum Pump - Dry pumps vs Oil Pumps
>
> Dear All,
>
>  We have been using Dry pumps for turbo pump backing for Sputters, 
> E-beam evaporators. And are planning to swap to oil pump with an 
> anti-suck back valve, whenever required (in case dry pumps go bad).
>
> We would like to know whether any of you are using oil pumps are being 
> used as backing pump for Turbo / Cryo / DP.
>
> Any advice / suggestions would be greatly appreciated.
>
> Thank You in advance.
>
>
> Thanks & Regards,
> Pradeep Nyaupane
>
> Technical Superintendent,
>
> Equipment Maintenance Team In-charge,
>
> IITBNF, Electrical Engg Dept
>
> IIT Bombay, India
>
> Tel No. 02225764471(O)
>
> ------------------------------------------------------------------------
> Notice: This email and any attachments may contain proprietary (Draper 
> non-public) and/or export-controlled information of Draper. If you are 
> not the intended recipient of this email, please immediately notify 
> the sender by replying to this email and immediately destroy all 
> copies of this email.
> ------------------------------------------------------------------------
>
> _______________________________________________
> labnetwork mailing list
> labnetwork at mtl.mit.edu
> https://urldefense.proofpoint.com/v2/url?u=https-3A__mtl.mit.edu_mailman_listinfo.cgi_labnetwork&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=gl_2fLZA_-_JfH_dOmx7ug&m=r5rIOAO6mwwu499DOGlm3KInSe3pP9iF64SaEDshfYA&s=-w3DLimaT2XywZG8S4xth595hMvyNcFtINhPI6ZvaUw&e=

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20191104/dbb7eb78/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 1923 bytes
Desc: not available
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20191104/dbb7eb78/attachment.jpg>