ORIGINAL: Craig B.
The membranes also clog up very quickly over time due to microbial growth within the membrane. Some of them run ok for a while but will quickly become sufficiently obstructed to cause a problem even if they do not create one immediately.
Craig.
I've never in my five years of jet flying had any noticeable microbial growth in any part of my fuel systems. Pure luck??
Using fresh Jet A1 from nearby airport, oils like everybody else - Exxon, Aeroshell, DTE Ligth etc.