Oil Separator outlet design question

[Stewie007]

I'm considering the method of returning oil to the compressor from the separator and I'm at odds as to how I can do it. The obvious decision seems to be to discharge it through the suction line close to the compressor. I am considering another conclusion, but I'm not certain of its feasibility.

I am going to be modifying the compressor to add an oil drain. The drain will have direct access to the oil chamber. As you might guess I am thinking of piping the oil separator oil outlet directly to that port for direct oil return. However, I am not certain of its feasibility. The solenoid controlling the drain line would be on a 5 second circuit (given active power through the compressor).

What do you think?

[DetroitAC]

I'm not sure how you mean to control this oil return line. How would you sense the oil level and adjust?? If your control is not right and you have the oil return line open more than it should be, you'll be blowing vapor into the oil sump. You'll be foaming the oil, maybe... Seems safer to dump into the suction line

[runmc]

The way your talking your compressor is a rotary. Where are you talking about putting the drain? If you put it in the top of the compressor, that is high pressure side.

[Stewie007]

I'm not sure how you mean to control this oil return line. How would you sense the oil level and adjust?? If your control is not right and you have the oil return line open more than it should be, you'll be blowing vapor into the oil sump. You'll be foaming the oil, maybe... Seems safer to dump into the suction line

That's sort of what I was thinking. The separator is not one of their newer models with an internal valve mechanism that opens when a sufficient oil level has been reached. Its a Temprite 340 series and the only way to control the oil drain is by solenoid. I got the thing for 25 bucks, so it seemed like a good move. The other option was to get a 900 series, but that would be a lot more costly.

The way your talking your compressor is a rotary. Where are you talking about putting the drain? If you put it in the top of the compressor, that is high pressure side.

Its a Rotary Indeed. I am putting the drain on the low side at the bottom of the end cap for direct oil chamber access... Much Easier to change if need be. Its a Horizontal HGA9468ZXA. Already have assurances that it is in the right spot (or will be), but based on what Det said above I think I'm just going to keep it as a drain.

[Stewie007]

Could I perhaps install an oil return float between the separator and the compressor?

That would keep it from sending vapor to the oil, no?

[DetroitAC]

A float is ideal since it is responding to the actual rate of oil return rather than assumptions

*although float valves do have their own issues

[Stewie007]

*True.....

I think I'll stick with discharging the oil directly into the suction line just after the CPR valve. Its less expensive that way. A float would probably cost nearly as much as a new sep with a float already installed (like a Temprite 900 series or similar).

Of course, I am having difficulty finding out how expensive these things are......