I've seen plenty of 90* pipe to hose barb fittings in the size I want, but none come with a flanged nut to hold the fitting in place on the tank wall. I've tried to find the nuts online as a separate item, but no luck there either. Is this really that hard, or am I missing something obvious here?
If you're just trying to install it in a threaded fitting already installed in the tank, there's no need for a nut on any thread-barb tank fitting...they're self-sealing. Just wrap the threads in teflon tape and screw them in...being careful not to OVERtighten. That can crack the female "collar" in the tank. Just hand tight, plus enough to aim any elbow in the direction it needs to go. However, unless your vent line can be relatively horizontal, I wouldn't use a 90 on the tank...use a straight fitting and let the vent line arch toward the thru-hull.
If you're trying to relocate the vent fitting on the tank, you don't need access to the inside of the tank to do that, thanks to a li'l doodad called the Uniseal
UNISEAL
Uniseal Instructions
Drill a clean hole with a hole saw...insert the Uniseal (it helps to read the diirections...then use any PVC straight or 90 from the plumbing department of any hardware store for your hose fitting. It should NOT be threaded...smooth on both ends. The Uniseal does NOT leak!
It would prob'ly be a good idea to TALK to the folks at Aussie Globe (the Uniseal mfr) to make sure you get the right size Uniseal to fit a PVC fitting that has an OD (outer diameter) that fits the hose size (hose sizes are always stated as the ID--inner diameter) that you want. And also make sure the PVC has the right size OD...'cuz wall PVC plumbing parts can vary in wall thickness.
If you still have questions, give me a shout, and I'll help you get it sorted out.
