Compressor cylinder inspection question

[wdeutsch]

Looks like I'm good to go on the stages moving air as they should. Stage 1 and 2 definitley did. Stage three inlet was a bit tough to diganose, as the pipe connecting the inlet valve to the ?? (The cylinder to the left of the oil dipstick with the large PRV. I'm guessing it's a sparator of some sort to vent water/oil?) - anyway, that tube is too short to flex enough to get an end out without disassembling a lot more. So, that one is still a bot of an unknown. The reed valve on the outlet also appeared to check out per your procedure, Iain. So, feeling relieved!

That said, I could peek into the tube leading into the stage 3 inlet and it seemed to have a fair bit of black/oily residue in it. I had assumed it would be fairly clean, that far through the process? Thoughts on whether that is a concern or not?

Power cord shows up tomorrow, I hope, so maybe it'll be showtime. If it shows up late in the day, I may still try to pop off the head of the stage 3 cylinder just to see how dirty things are in there. No sense buying new filters if I'm just gonna gunk 'em up because of trapped goo in there, no?

 

[iain/hsm]

No sense buying new filters if I'm just gonna gunk 'em up because of trapped goo in there, no?

On your first part. Agreed entirely.

Second part: Light oil on the discharge side of the valve on the head is ok but on the inlet side of the head not so.
Check why didn't the interstate separator do a job. I doubt the compressor was decommissioned and inhibited for long term storage but inhibiting oils can be a problem. Also if the original mineral based oil was used beyond its run in period and a synthetic dieter was put in well after that so the junk you see is the softened old carbon deposits from the old oil.

Third part:

Rule of thumb on running up an old compressor for the first time is to use the old fitted filter even if the old existing chemical cartridges is dud or on its way out. But only while you test and commission the pump. And definatly prior to filling a bank or filling a real in use scuba cylinder.

For this most engineers will have a (not for scuba) aluminium cylinder for testing and commissioning and would never fill into any customers in use scuba cylinder for any reasons too many to list.

Aluminium is preferred as they don't rust like a steel cylinder would even if the filter chemical is a dud.
After filling a years worth of old pumps in for service/repair you simply pop the cylinder valve inspect and stick the cylinder on a radiator to dry for the day. The cylinder is also used for a before and after air test after commissioning and new cartridges are fitted prior to sign off with a second air purity check

Because you test into the test cylinder of a known volume you can also check the flow the compressor by recording time to fill from empty to full. For example a standard aluminium 80 to 3000psi is easier to calculate in bar than psi. 11 litres water capacity cylinder volume by 207 Bar (3000psi) 207x 11 is 2277 litres divide that by 28.32 and you get 80.40 Cubic feet
An engineer would use a calibrated flow meter but for you do the above and its not required.
Now 80 cubic foot divided by the time taken to fill in minutes is your flow near enough and saves you having to do an RPM strobe test on the flywheel. But if you've got one for verification why not.

Regarding the oil pump by what you said earlier about having an oil pressure gauge fitted already I would go with that and save yourself the faff of adding another just for a run up test.

1. Spin Test by hand inspection valve check
2. Motor run test without the belts check all electricals and rotation

And your on your way for the main engine start.

Now in your case by all means lift the lid and inspect inside the filter chemical cartridge prior to the run up test and I would also drop the water /oil interstage separators and take a peek