Wet bulb indicator

[imer]

I would like to pick the brains of you experienced individuals out there.
We are in the process of pulling a vacuum on our machine. The machine is a 2550 ton York Turbomaster.
The instrument we are using to check the wet bulb is a Supco VG60. We have been running our vacuum pump for a couple of days now, yet the indicator shows only 100-1500 microns. It would not go any lower than that. I was hoping for at least 700 microns. Any suggestions? Is the Supco gauge reliable. What is the ideal dry system? Any recomandations on alternate micron gauges?

[Wild Leg]

Wet bulb?

I think you're mixing terminology here.

How many times have you changed the oil in your vacuum pump?

Swept the system with nitrogen?

The VG60 is somewhat entry-level, as micron gages go.

Supco makes a better quality one, as does Robinair & Yellowjacket.

Try and find one with a digital readout.
Ask the local supply house which one they are selling more of.

[imer]

You are right, bwal2. I am mixing terminologies. In any case a deep vacuum would indicate the dryness off the system. In your opinion is 700 microns acceptable?

[imer]

I would like to pick the brains of you experienced individuals out there.
We are in the process of pulling a vacuum on our machine. The machine is a 2550 ton York Turbomaster.
The instrument we are using to check the vacuum is a Supco VG60. We have been running our vacuum pump for a couple of days now, yet the indicator shows only 100-1500 microns. It would not go any lower than that. I was hoping for at least 700 microns. Any suggestions? Is the Supco gauge reliable. What is the ideal dry system? Any recomandations on alternate micron gauges?

[Wild Leg]

Originally posted by imer
... In your opinion is 700 microns acceptable?

Do you trust that instrument?
Has it been cleaned & calibrated?
700 microns is pretty low, but you have a very expensive piece of equipment there.
The lower the better, obviously.
I don't know if your pump is capable of going lower.
Have you tested it against just the micron gage?
Where do you have the VG60 connected?
Near the vacuum pump?
If so, move it.
It needs to read the system, not the pump.
Is 700 a standing test, or with the pump running?
You are getting close, & filter driers can hold residual moisture.
There are others on this forum that will have more experience.

Thanks for asking. :)

[viceman]

what kind of hoses are you using. we usually use copper tubing and flare nuts in the largest size possible for critical evacuations. change oil frequently and if you are not confident your gauge is accurate buy or borrow another to compare readings.

[who cares]

I hate to ask, but are you sure the machine doesn't have any leaks.

[RichardL]

[QUOTE]Originally posted by imer
[B]You are right, bwal2. I am mixing terminologies. In any case a deep vacuum would indicate the dryness off the system. In your opinion is 700 microns acceptable?

The 700 micron reading is absolutely acceptable assuming it does not rise more than say....10% in an 8 hour period....
Should it rise more than that, methinks you got leaks..
The 10% number was POA....

[mancuso jr]

you guys need to check the EPA 608 code that we are all suppose to know it says atleast 500 microns. I know you all know that just a freindly reminder

[RichardL]

The 500 micron required is written for "Recovery" purposes.
"If" the 500 micron level is attainable, and it seldom is due to leaks etc., then we know that we "All" recover to this Lvl....

[Engineerman]

have you changed the oil in the pump?? did you leak check the machine??