Monday, August 2, 2010

Yet More Leak Testing.

Well the past few days have been filled with leak testing. It has been frustrating. Good silver solder joints going bad. Which means they were not good in the first place!
This is my blanking cap for the top of the pump barrel. Its only 6mm thick. That is the thickest I had unfortunately. I cut a groove on the lathe. As you can see it chattered a bit. Its not a big deal because it not the mating surface.

I polished the outside ring where the o-ring would press against. That all worked out well.
You see, the piece of Al. was not big enough to be a flange too, so I used this piece of acrylic as a clamp. The real problem is that the acrylic bend when you start getting near the right compression on the o-ring (20%). This, I found was deforming the cap slightly. Enough to pop the J B Welded brass adapter off.

It held long enough to do the first few tests. I am doing them at 4 Bar.

Initially I had two small leaks. So I fixed them with great enthusiasm and retested. I then found I had four leaks...

This pattern went on for two days till I finally had it sealed. So now I believe my pump is air tight. Vacuum tight? We'll see.

New Pump Interior

After the failure of my two stage chimney design I was convinced to try a single jet instead. Above is a photo of the 2" copper pipe I'm using. Its upside down here. The small holes are for the condenced oil to flow back in to the middle and the larger ones, higher up are for vapor from around the outside to whizz in to the chimney and go up.
Again this is upside down. The skirt in this case is the same diameter as the interior of my pump barrel. This is only a cap over the condensed oil not a down jet deflector.

I cut 5 nicks in the cone with an angle grinder to allow oil to flow back in to the reservoir. The cone here is another stainless steel funnel.

I don't have a pic but the deflector is also one of these funnels. I have an 8mm clearance around the circumference of the cone for the vapor to bridge before it hits the pump wall.
Fingers crossed.