"Bill Bligh" wrote:

Trying to assemble a diesel fuel polishing device from filters,
pipes ( nipples ), gauges, magnet, a pump, hoses and many
valves.

Loctite 242 used by one manufacturer, Loctite 55 sold
for the purpose by plumbing supply company. The usual
sodden wharf rat layabouts urge teflon tape - but every
article or book which mentions teflon tape and diesel
fuel warn against the stuff - use the engine as a mooring
after using teflon...
snip

Teflon TAPE is to be avoided on ALL fuel systems since bits of it will
break off and eventually plug the nozzle orifices of the fuel systems.

Use teflon paste type joint compounds.

Personally, I like bronze ball valves with S/S hardware along with
Racor filters, but YMMV.

Have fun.

Lew