Thank you all for your wonderful suggestions (see summary below)
What I actually ordered was EPDM 70 durometer which works just fine. It costed about $5 for a pack of 10 with another $5 shipping charge for next day delivery.
http://www.mcmaster.com/#9557k306/=101x5vd
Dr. Gopal Subramaniam
Department of Chemistry & Biochemistry
Queens College - CUNY
Flushing, NY 11367
The following suggestions were received.
1. Try McMaster Carr. I am guessing it broke because it froze. You might want to try Fluorosilicone instead of Buna-N. See
http://www.mcmaster.com/#o-rings/=101wzk3. However, I don't know which dash number you need.
2. I believe you have a Bruker variable-temperature accessory with a standard NW 50 (sometimes called KF 50) O-ring assembly joining the heater assembly with the neck of the dewar. These O-ring assemblies are commonly used on both high-vacuum and cryogenic apparatus. You can order replacement Viton fluoroelastomer O-rings (for low temperature operation) from Edwards High Vacuum:
https://shop.edwardsvacuum.com/fittings/nw/508/528/h02124038/view.aspx
Alternatively, you can order replacement NW 50 O-ring assemblies from McMaster-Carr supply company (cat. No. 4518K65):
http://www.mcmaster.com/#4518k65/=1021mzi
3. I ordered them from Marco Rubber :item number B1030-330, material BUNA-N, ID 2-1/8, OD 2-1/2.
4.
5. I haven't ordered one in many many years, so I don't have the cat# anymore, but it's a standard part usually used for vacuum systems, and I had ordered from SIS.
http://www.sisweb.com/vacuum/fittings/ro.htm
6.
http://www.mcmaster.com/#o-rings/=101wb5n for your choices
7. Actually, I just showed my hardware store the broken one and they had a replacement with same dimensions.
Received on Thu Dec 10 2015 - 08:52:57 MST