Many thanks to everyone for the 30+ replies I received. I will probably end up using the amber latex tubing like the majority of people recommended. I will try and summarise the responses below.
The braided metal transfer lines can be repaired, but it is expensive, and likely not cost-effective.
The light brown rubber tubing is commonly called "amber latex". Most people use tubing with an outer diameter of 3/8" and wall thickness of 1/8". It can be purchased from Fisher, VWR, McMaster-Carr, or Macalaster Bicknell of New Jersey. Many people mentioned that it has a tendency to shatter and some people reduce the danger from flying shards of frozen latex by enclosing the tubing with black insulating foam tubing typically used for domestic water pipes or air conditioning.
Another recommendation was the use of flexible teflon tubing. This was normally connected to the nitrogen tank at one end and the magnet at the other by short lengths of silicon or amber latex tubing.
Brendan M. Duggan, PhD
NMR Facility Director and Associate Project Scientist
Skaggs School of Pharmacy and Pharmaceutical Sciences
University of California at San Diego
9500 Gilman Drive, MC 0684
La Jolla CA 92093
office phone: (858) 534-8763
lab phone: (858) 822-7826
cell phone: (858) 692-2298
email: bmduggan_at_ucsd.edu
http://sopnmr.ucsd.edu
Received on Mon Jan 20 2014 - 13:05:14 MST