Yes this ball lock post (KEG477) will fit into a manifold with British Standard Pipe Taper (BSPT) such as D1802. I'm not sure what BSPP is but I would assume it's the same as BSP BSPT or BST which refer to the British pipe thread standards.

These were not designed to fit a manifold. These are considered long threads (actually .800 inch) so these are actually a 1/4" male BSPP thread. A true pressure 1/4 " BSPT fitting has only about .437 inch of mating threads to mate with a manifold. This is a thru-hole application design that relies on the compression of o-ring to seal. Designed for a 1/2" thru hole or tapped 1/4" BSPP.

The fitting for the beer gun is different. It may fit the beer gun fitting is MFL and the gas Post fitting is MPT. If you used a MFL to MPT adapter that could work.

The gas and liquid keg posts are shaped slightly different. This is the gas post that threads into a ball-lock keg. You connect your gas connector to it

This is for Gas In so you would need a Gas disconnect with a 1/4 or 5/16 barb depending on your tubing. I use mine on my fermonster to push Co2 into my keg during fermentation.

Yes. This is exactly the purpose for which I purchased this item and it has worked great. I added a pair of o-rings (1/2" ID x 5/8" OD) inside and outside of the lid and it has worked great.

It will fit on any flat surface. Nut and oring are included.

It is too small. I thought it would fit mine too. I may tap a hole to fit one though

NPT/NPS and BSP threads are not compatible due to the differences in their thread forms and not just the fact that most sizes have a different pitch.

No 1/4” NPT is not the same as 1/4” flare.

My attempt was to sandwich my post between a predrilled triclover disk. My problem and I was not successful so far is that my holes drilled in the triclover disk are too close together. I'm using a ss coupler that has a 1/4" female end the other end is male 3/8". The threads are NPT. The female thread is tapered and the male thread is straight. A 1/4" NPT will tighten and seal on the that end with teflon tape the male end needs a 3/8" NPT nut and a gasket to seal. I'm not sure. but I believe the flare fitting is a different thread. It would be a force fit and you would probably destroy the threads for future use. I would suggest going to your big box store and testing some of the stock fittings on the mounted thread guides to see what fits properly. If you only get a 1/4 turn or less on turning by hand the thread aren't compatible. To solve my problem I'm going to have to drill another triclover disk with the holes spaced wider apart to allow a nut and o-ring gasket seal on the bottom side of the disk. Good luck.