Brief Description: Fuel system design and installl (part 1)
The sight gauge itself if modeled after an idea circulated on our builder's list. Some clever use of aluminum tubing and tight-fitting tygon tubing and nipple fittings makes for a sturdy sight gauge. (See link https://www.murphybuilders.net/download/file.php?id=2211)
The NPT fittings here (and elsewhere) are beingused as bulkhead fittings by virtue of the unused threaded portions. Image 2 shoes this best: I added the correct number of aluminum washers so that the NPT fitting was snug to the outside feul fitting, while simultaneously sandwiching the wing-root bulkhead. Very secure and lightweight. The nipple fittings are inserted into the tygon tubing with a 'proseal-like' 2-part compound from aircraft spruce (recommended in the link I provide above). The pro-seal not only improves the seal, but acts as an adhesive that greatly solidifies the nipple fitting connection. On a test sample, I was unable to pull the fitting out of the tubing even after exerting 20-30 lbs of force. With the fittings firmly attached to the bulkheads, these joints will never even see such loads.
