Pressure Test #2

Success!  The dual lipped oil seal worked perfectly.  Below the aluminium housing is bolted and sealed to the PVC cap.  The shaft seal is on the lower right, the top being exposed to the pressure.  The whole chamber was submersed in water for 5 minutes to make sure there were no leaks, and now its sitting in the shed to make sure that it can keep it's pressure (it has done over the last half an hour).  The shaft can be moved easily by hand with no leaking as it rotates.

14/04/2015

14/04/2015

Pressurized to 30 PSI, double the maximum pressure the sub will endure.

15/04/2015

15/04/2015

Depending on the results of the chambers ability to hold pressure over the next few hours, it'll be time to take the final steps to incorporate the seals into the sub.

Air System

During the last few weeks I've been finishing off little bits and pieces within the hull, which are; the ballast release system, air system, battery brackets and water pipe brackets. Once they're done and I do a test on the new shaft seals and finish off the rear, then I can begin work on the conning tower, hatch and electronics, and then start testing!

Here I'm setting up the compressor to be mounted inside the sub.  During test runs the cylinders got very hot and the pipes became a little loose on their connections, that's why I'm adding two fans (one per cylinder) to help keep it cool.  I might even add a temperature sensor to be sure it's not overheating.  The pump will be operated automatically during a dive to re-compress the air that is escaping from the ballast tanks.  I also have the option to compress the air from inside the hull and into the tanks - yes the hatch will have to be open for this so it'll be for surface use only.

8/04/2015

The brackets that will hold the pump inside the hull.  The rubber feet help stop the vibrations entering the hull.  I would think in a confined space under water the vibrations would be pretty annoying...

8/04/2015

The air inlets for each cylinder were some metric thread that I couldn't find a fitting for, so I had to take it apart, drill the hole to 12 mm and tap it to 1/4" BSP so it would join to the rest of the air system.

10/04/2015

All 12 air valves hooked up, along with the pressure regulator and water trap.  The air in the tanks can be compressed to a max of 150 PSI, but the valves can only take a max of 100 PSI, so the regulator was needed to lower it a little.  I could have simply put the whole system at a max of 100 PSI but that would mean I would have little air on board for an emergency - the more air the better.

11/04/2015

These valves sit on behind the pilot on the left hand side.  During normal operation they'll both be closed, but the top valve can be opened up to let the compressed air out of the tanks (perhaps to equalize pressure within the hull and the outside), it can also take an external air source, in case the on board compressor has failed.

The lower valve is the alternate air inlet for the on board compressor (or an outlet for the ballast tanks).  Before anything gets compressed it goes through the air filter.

11/04/2015

The air regulator.  Before going into the regulator, a pressure gauge will get hooked too it, it'll show the total pressure within the tanks.  Behind the regulator a second gauge will be attached, it'll show the pressure going into the valves.  After the regulator the air goes into both banks of solenoid valves, along with outlets to the two main ballast tanks for a manual override, so if the power fails I can still flush the main tanks and ascend.

11/04/2015