Workstation with/without lubricator

by Doug McCrary
(San Diego, CA USA)

Proposed FR-L installation

Proposed FR-L installation

I'm setting up an area where I want to run an air screwdriver and a small die grinder, serially, not at the same time.

The grinder came with an in-line oiler, so I figure I should use it.

Ideally I'd have separate compressors and lines for each, but that's a bit much:}

So what do you think of this:

Drop line to a tee with drain valve at the bottom;

Tee into an FR combo out to another tee dropping down to a connector for the screwdriver, and then an ell to another connector where the oiler would connect to the grinder.

My main concern is slight, and doesn't really matter much, but would there be much chance of oil backing through to the screwdriver?
Far as I'm concerned your work is thoroughly professional, Doug.

No, air flows from high pressure to low, and since air tools by their design have an opening to atmosphere, air flowing into the line to any air tool will always flows towards the too, and will not back up.

Is that a mini-frl in the photo? If so, with it, and the tees and ells, you might find your air tool getting a bit starved for air. If so, you will want to consider moving to a full sized f/r with higher flow capability, and using larger lines to feed the tools to offset pressure loss through plumbing, but only if you perceive a problem using either of the air tools.



Comments for Workstation with/without lubricator

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Aug 02, 2013
by: Doug in

Thanks, Bill.

Regarding air flow(s).

Thing is, both lines are at about 90psi static.
When the screwdriver comes on, the pressure drops to about 80psi, so at least some air must be flowing back toward the open air tool from the grinder line.

The grinder is supposed to only use around 2cfm, and the screwdriver about 6cfm, while the regulator is rated 60cfm @ 100psi.

I did notice there was a slow drop-off of pressure just before the regulator. I was thinking everything was at least 3/8 with 1/4 connectors. The drop-off reminded me that I've been going thru a 1/8 orifice on the unregulated output from my pig. I moved that to my regulated output from the pig and the drop-off nearly vanished.

So, in short, it works. Yea.
Good. If really concerned about back flow, install an in line check valve to prevent it.


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