Once again Wikipedia has a great report on fibers. This time the subject is PBI fiber. Some packing companies use this fiber in valve packing. One interesting thing is it is not good for chemical resistance. It is good for high temperature and has been used as welding apparel and fireman equipment.
I do not know from this writeup how it works as a pump or valve packing.
I do not know from this writeup how it works as a pump or valve packing.