Hi all, I'm looking to buy a two stage vacuum pump. This may not be the best forum, and if some of you know a vacuum related forum then please do share.
This will be used in the lab as a roughing pump, or perhaps to back up a turbo molecular or diffusion pump. (and not for HVAC work). I found a recommendation on "The bell Jar"
http://www.belljar.net/chambers.htm#Pumps
for the Robinair 15600.
http://www.amazon.com/Robinair-15600...productDetails
Some of the reviews are less than glowing... (to say the least).
But that made me turn to the Yellow jacket.
http://www.amazon.com/Yellow-Jacket-.../dp/B0016H12I0

Does anyone have experience with either of these?
Or some other model you like.
I'm steering away from the "tradition" lab pumps made by Edwards, Leybold, Alcatel etc. as these all go for more than a kilo buck.

Thanks
George H.
(posted to SED and RCM)

wrote in message
...
Hi all, I'm looking to buy a two stage vacuum pump. This may not be the
best forum, and if some of you know a vacuum related forum then please do
share.
This will be used in the lab as a roughing pump, or perhaps to back up a
turbo molecular or diffusion pump. (and not for HVAC work). I found a
recommendation on "The bell Jar"
http://www.belljar.net/chambers.htm#Pumps
for the Robinair 15600.
http://www.amazon.com/Robinair-15600...productDetails
Some of the reviews are less than glowing... (to say the least).
But that made me turn to the Yellow jacket.
http://www.amazon.com/Yellow-Jacket-.../dp/B0016H12I0

Does anyone have experience with either of these?
Or some other model you like.
I'm steering away from the "tradition" lab pumps made by Edwards, Leybold,
Alcatel etc. as these all go for more than a kilo buck.

Thanks
George H.
(posted to SED and RCM)

Why not just buy a any name brand two stage refrigeration pump? Its just a
roughing pump. Are you worried about lubricant contamination from the pump?

Am I missing something? The Robinair 15800 is only about $250 bucks so its
worth a shot I think. Refurbed 15600s can be found for under $200 (plus
shipping).

wrote:
Hi all, I'm looking to buy a two stage vacuum pump. This may not be the best forum, and if some of you know a vacuum related forum then please do share.
This will be used in the lab as a roughing pump, or perhaps to back up a turbo molecular or diffusion pump. (and not for HVAC work). I found a recommendation on "The bell Jar"
http://www.belljar.net/chambers.htm#Pumps
for the Robinair 15600.
http://www.amazon.com/Robinair-15600...productDetails
Some of the reviews are less than glowing... (to say the least).
But that made me turn to the Yellow jacket.
http://www.amazon.com/Yellow-Jacket-.../dp/B0016H12I0

Does anyone have experience with either of these?
Or some other model you like.
I'm steering away from the "tradition" lab pumps made by Edwards, Leybold, Alcatel etc. as these all go for more than a kilo buck.

I've only used "expensive" lab pump, keep in mind they're never cheap
unless they're used or remanufactured- which is actually a good way to get
one.

It all comes down to what pumping capacity do you need, what vapors (and
how much moisture) are you pumping etc.

All the "expensive" pumps are designed to run nonstop forever, or until
you mess up the oil. The HVAC pumps you see at the pawn shop are not built
or rated for this sort of duty, and the price shows this.

Keep in mind that tossing away $250 pumps may still be cheaper than
sending in a good pump for rebuild if you mistreat it. The worst thing you
can do is let water condense in your oil, then shut the pump off, letting
everything rust and corrode. I've not asked them, but it looks like the
commercial HVAC people just replace their pump oil after any big job. This
is based off the number of pump oil containers in the trash after the guys
leave.

On Wednesday, April 30, 2014 4:11:37 PM UTC-4, Cydrome Leader wrote:
wrote:

Hi all, I'm looking to buy a two stage vacuum pump. This may not be the best forum, and if some of you know a vacuum related forum then please do share.

This will be used in the lab as a roughing pump, or perhaps to back up a turbo molecular or diffusion pump. (and not for HVAC work). I found a recommendation on "The bell Jar"

http://www.belljar.net/chambers.htm#Pumps

for the Robinair 15600.

http://www.amazon.com/Robinair-15600...productDetails

Some of the reviews are less than glowing... (to say the least).

But that made me turn to the Yellow jacket.

http://www.amazon.com/Yellow-Jacket-.../dp/B0016H12I0



Does anyone have experience with either of these?
Or some other model you like.
I'm steering away from the "tradition" lab pumps made by Edwards, Leybold, Alcatel etc. as these all go for more than a kilo buck.

I've only used "expensive" lab pump, keep in mind they're never cheap
unless they're used or remanufactured- which is actually a good way to get
one.

It all comes down to what pumping capacity do you need, what vapors (and
how much moisture) are you pumping etc.

All the "expensive" pumps are designed to run nonstop forever, or until
you mess up the oil.
Ahh OK that makes sense. (There were always several gurgling away 24/7 back in the lab in grad school.)
The HVAC pumps you see at the pawn shop are not built
or rated for this sort of duty, and the price shows this.
Yeah this will be more limited duty. But I guess I could picture leaving it on over night.

Keep in mind that tossing away $250 pumps may still be cheaper than
sending in a good pump for rebuild if you mistreat it. The worst thing you
can do is let water condense in your oil, then shut the pump off, letting
That's what the ballast value is for... I think? (not a vacuum expert)

everything rust and corrode. I've not asked them, but it looks like the
I'ts kinda too bad 'cause pumping on water is fun.
commercial HVAC people just replace their pump oil after any big job. This
is based off the number of pump oil containers in the trash after the guys
leave.

Thanks for the advice.

George H.

On Wednesday, April 30, 2014 3:50:25 PM UTC-4, Bob La Londe wrote:
wrote in message


Why not just buy a any name brand two stage refrigeration pump? Its just a
Excuse my ignorance, but is the refrigeration pump different from the HVAC pump I posted? Ohh... it'll be for continuous duty.
roughing pump. Are you worried about lubricant contamination from the pump?
Well not at the moment.

Am I missing something? The Robinair 15800 is only about $250 bucks so its
worth a shot I think. Refurbed 15600s can be found for under $200 (plus
shipping).
Nope I just didn't look at the Robinair 15800.

Thanks I'll look into refrigeration pumps.

George H.

wrote:
On Wednesday, April 30, 2014 4:11:37 PM UTC-4, Cydrome Leader wrote:
wrote:

Hi all, I'm looking to buy a two stage vacuum pump. This may not be the best forum, and if some of you know a vacuum related forum then please do share.

This will be used in the lab as a roughing pump, or perhaps to back up a turbo molecular or diffusion pump. (and not for HVAC work). I found a recommendation on "The bell Jar"

http://www.belljar.net/chambers.htm#Pumps

for the Robinair 15600.

http://www.amazon.com/Robinair-15600...productDetails

Some of the reviews are less than glowing... (to say the least).

But that made me turn to the Yellow jacket.

http://www.amazon.com/Yellow-Jacket-.../dp/B0016H12I0



Does anyone have experience with either of these?
Or some other model you like.
I'm steering away from the "tradition" lab pumps made by Edwards, Leybold, Alcatel etc. as these all go for more than a kilo buck.

I've only used "expensive" lab pump, keep in mind they're never cheap
unless they're used or remanufactured- which is actually a good way to get
one.

It all comes down to what pumping capacity do you need, what vapors (and
how much moisture) are you pumping etc.

All the "expensive" pumps are designed to run nonstop forever, or until
you mess up the oil.
Ahh OK that makes sense. (There were always several gurgling away 24/7 back in the lab in grad school.)

Those mechanical vacuum pumps are pretty amazing in that all they can do
to update them is change the paint jobs every decade or so.

The HVAC pumps you see at the pawn shop are not built
or rated for this sort of duty, and the price shows this.
Yeah this will be more limited duty. But I guess I could picture leaving it on over night.

Keep in mind that tossing away $250 pumps may still be cheaper than
sending in a good pump for rebuild if you mistreat it. The worst thing you
can do is let water condense in your oil, then shut the pump off, letting
That's what the ballast value is for... I think? (not a vacuum expert)

Yup. The gas ballast is just a valve that lets a pump suck in air with
whatever you're pumping. The idea is as long as the pump is still pumping
air along with water vapor from whatever you're evacuating the water vapor
won't condense into water droplets in the oil leaving you emulsified oil
and water. Constantly sucking on some fresh air also keeps the pump
running hot so the water in the oil will evaporate. Once the water load is
gone, you close the gas ballast and the pump does it's stuff to "full"
vacuum.

The problem with gas ballasts is they cause the pumps to emit a nasty fog
from the outlet of super fine oil droplets that will pass though nearly
any sort of filter. They do make mist eliminators to prevent this awful
fog from covering everything near the pump. You can also just pipe the
stuff outside and call it "water vapor" if anybody asks.

everything rust and corrode. I've not asked them, but it looks like the
I'ts kinda too bad 'cause pumping on water is fun.

Since it's sort of impossible to not pump water vapor, pretty much all the
pump makers will have the water pumping capacity as part of the spec
sheet.

Take a look at Harbor Freight. They have 2 vacuum pumps. I haven't used
either, so this is no reccomendation, merely the hope you
look, and report your findings here.

Hul

wrote:
Hi all, I'm looking to buy a two stage vacuum pump. This may not be the best forum, and if some of you know a vacuum related forum then please do share.
This will be used in the lab as a roughing pump, or perhaps to back up a turbo molecular or diffusion pump. (and not for HVAC work). I found a recommendation on "The bell Jar"
http://www.belljar.net/chambers.htm#Pumps
for the Robinair 15600.
http://www.amazon.com/Robinair-15600...productDetails
Some of the reviews are less than glowing... (to say the least).
But that made me turn to the Yellow jacket.
http://www.amazon.com/Yellow-Jacket-.../dp/B0016H12I0

Does anyone have experience with either of these?
Or some other model you like.
I'm steering away from the "tradition" lab pumps made by Edwards, Leybold, Alcatel etc. as these all go for more than a kilo buck.

Thanks
George H.
(posted to SED and RCM)

On Wednesday, April 30, 2014 5:14:57 PM UTC-4, Cydrome Leader wrote:
wrote:
snip
I've only used "expensive" lab pump, keep in mind they're never cheap
unless they're used or remanufactured- which is actually a good way to get
It all comes down to what pumping capacity do you need, what vapors (and
how much moisture) are you pumping etc.
All the "expensive" pumps are designed to run nonstop forever, or until
you mess up the oil.
Ahh OK that makes sense. (There were always several gurgling away 24/7 back in the lab in grad school.)

Those mechanical vacuum pumps are pretty amazing in that all they can do
to update them is change the paint jobs every decade or so.

The HVAC pumps you see at the pawn shop are not built
or rated for this sort of duty, and the price shows this.
Yeah this will be more limited duty. But I guess I could picture leaving it on over night.

Keep in mind that tossing away $250 pumps may still be cheaper than
sending in a good pump for rebuild if you mistreat it. The worst thing you
can do is let water condense in your oil, then shut the pump off, letting
That's what the ballast value is for... I think? (not a vacuum expert)

Yup. The gas ballast is just a valve that lets a pump suck in air with
whatever you're pumping. The idea is as long as the pump is still pumping
air along with water vapor from whatever you're evacuating the water vapor
won't condense into water droplets in the oil leaving you emulsified oil
and water. Constantly sucking on some fresh air also keeps the pump
running hot so the water in the oil will evaporate. Once the water load is
gone, you close the gas ballast and the pump does it's stuff to "fulum.

The problem with gas ballasts is they cause the pumps to emit a nasty fog
from the outlet of super fine oil droplets that will pass though nearly
any sort of filter. They do make mist eliminators to prevent this awful
fog from covering everything near the pump. You can also just pipe the
stuff outside and call it "water vapor" if anybody asks.
Yeah, I've gotta pipe the output outside.
(the lab space also has optics... the last thing I need is oil vapor.)

everything rust and corrode. I've not asked them, but it looks like the
I'ts kinda too bad 'cause pumping on water is fun.

Since it's sort of impossible to not pump water vapor, pretty much all the
pump makers will have the water pumping capacity as part of the spec
sheet.

I don't think this is on the spec sheet, but I'd give up a lot to have a quite pump. That may be an advantage for the smaller sizes.

George H.

On Wednesday, April 30, 2014 5:35:44 PM UTC-4, Hul Tytus wrote:
Take a look at Harbor Freight. They have 2 vacuum pumps. I haven't used
either, so this is no reccomendation, merely the hope you
look, and report your findings here.

Hul

I'm sure... If you go to amazon, there are ~100's vacuum pumps.
The Chinese stuff is all cheaper. I've no time to survey the options.

George H.

wrote:

Hi all, I'm looking to buy a two stage vacuum pump. This may not be the best forum, and if some of you know a vacuum related forum then please do share.

fired this volley in news:6969535a-19d2-42f9-b883-
:

Nope I just didn't look at the Robinair 15800.

Thanks I'll look into refrigeration pumps.


George, I've used Robinaire pumps for decades. I've never had a bad one
out of the box, and they work for ten years at least in twice-weekly
service, if you change the oil on every job (which is _required_ for
warrantee).

Those folks who got 'burned' probably bought from questionable vendors
who were selling refurbs as new, or pumps known to have been dropped from
pallets, etc. It doesn't take much impact to break a vane.

They work great, and if you get a bad one, the vendor should replace it--
no questions asked.

LLoyd

On Wednesday, April 30, 2014 7:45:33 PM UTC-4, Lloyd E. Sponenburgh wrote:
fired this volley in news:6969535a-19d2-42f9-b883-

:

Nope I just didn't look at the Robinair 15800.



Thanks I'll look into refrigeration pumps.





George, I've used Robinaire pumps for decades. I've never had a bad one
out of the box, and they work for ten years at least in twice-weekly
service, if you change the oil on every job (which is _required_ for
warrantee).

Thanks Lloyd, If it's not too much trouble, can you tell me why you have to change the oil so often? I've only used vacuum pumps in a research setting. And there the only time I recall changing the oil was when I rebuilt an old pump, or when I burned up the oil in a diffusion pump.

George H.

Those folks who got 'burned' probably bought from questionable vendors
who were selling refurbs as new, or pumps known to have been dropped from
pallets, etc. It doesn't take much impact to break a vane.

They work great, and if you get a bad one, the vendor should replace it--
no questions asked.



LLoyd

fired this volley in
:

Thanks Lloyd, If it's not too much trouble, can you tell me why you
have to change the oil so often? I've only used vacuum pumps in a
research setting. And there the only time I recall changing the oil
was when I rebuilt an old pump, or when I burned up the oil in a
diffusion pump.

George H.

I use them for refrigeration jobs. Refrigerant, water, and 'gunk' from
systems will contaminate the oil. It's just good practice to change the
oil after any job where you've been pulling down an 'opened' system.

Just CYA. The oil is sure not expensive compared to a new pump, and the
job charge is set to cover it.

You could probably get away with almost never changing it if you were
pulling dry gasses. Water... eh! It emulsifies _some_ with the oil,
even when you open the bias valve.

Lloyd

On Wednesday, April 30, 2014 3:41:20 PM UTC-4, wrote:
Hi all, I'm looking to buy a two stage vacuum pump. This may not be the best forum, and if some of you know a vacuum related forum then please do share.


OK just to cap this thread. I bought an old Sargent Welch Duo seal 1400 on ebay last night. It was so cute I just had to buy it and take it home :^)
~$200 delivered.

Thanks for the input.

George H.

wrote:
On Wednesday, April 30, 2014 3:41:20 PM UTC-4, wrote:
Hi all, I'm looking to buy a two stage vacuum pump. This may not be the best forum, and if some of you know a vacuum related forum then please do share.


OK just to cap this thread. I bought an old Sargent Welch Duo seal 1400 on ebay last night. It was so cute I just had to buy it and take it home :^)
~$200 delivered.

That's a nice pump. I used to get parts for my Precision Scientific pumps
from the factory when they were made in Chicago. The Welch ones are still
made just outside the city.

On Thu, 1 May 2014 10:21:42 -0700 (PDT), wrote:

On Wednesday, April 30, 2014 7:45:33 PM UTC-4, Lloyd E. Sponenburgh wrote:
fired this volley in news:6969535a-19d2-42f9-b883-

:

Nope I just didn't look at the Robinair 15800.



Thanks I'll look into refrigeration pumps.





George, I've used Robinaire pumps for decades. I've never had a bad one
out of the box, and they work for ten years at least in twice-weekly
service, if you change the oil on every job (which is _required_ for
warrantee).

Thanks Lloyd, If it's not too much trouble, can you tell me why you have to change the oil so often? I've only used vacuum pumps in a research setting. And there the only time I recall changing the oil was when I rebuilt an old pump, or when I burned up the oil in a diffusion pump.

Vacuum pumps pull the moisture out of the HVAC system and into the
pump, which is filled with oil. Moisture is a contaminant, so change
the oil every time. With our old system pumps for automotive use, we
changed oil once or twice a year, but they kept working despite the
abuse. The Boss said "It's too expensive to change oil each time."

--
If government were a product,
selling it would be illegal.
--P.J. O'Rourke

Larry Jaques wrote:
On Thu, 1 May 2014 10:21:42 -0700 (PDT), wrote:

On Wednesday, April 30, 2014 7:45:33 PM UTC-4, Lloyd E. Sponenburgh
wrote:
fired this volley in
news:6969535a-19d2-42f9-b883-

:

Nope I just didn't look at the Robinair 15800. Thanks I'll look
into refrigeration pumps.


George, I've used Robinaire pumps for decades. I've never had a
bad one out of the box, and they work for ten years at least in
twice-weekly service, if you change the oil on every job (which
is _required_ for warrantee).
Thanks Lloyd, If it's not too much trouble, can you tell me why you
have to change the oil so often? I've only used vacuum pumps in a
research setting. And there the only time I recall changing the
oil was when I rebuilt an old pump, or when I burned up the oil in
a diffusion pump.

Vacuum pumps pull the moisture out of the HVAC system and into the
pump, which is filled with oil. Moisture is a contaminant, so change
the oil every time. With our old system pumps for automotive use,
we changed oil once or twice a year, but they kept working despite
the abuse. The Boss said "It's too expensive to change oil each
time."

-- If government were a product, selling it would be illegal. --P.J.
O'Rourke


I change mine after each use, but the oil gets collected and I let most
of the water settle out. Then it goes through a vacuum distillation
system to remove the rest.


--
Steve W.

"Steve W." wrote in message
...
Larry Jaques wrote:
On Thu, 1 May 2014 10:21:42 -0700 (PDT), wrote:
On Wednesday, April 30, 2014 7:45:33 PM UTC-4, Lloyd E.
Sponenburgh
wrote:

Vacuum pumps pull the moisture out of the HVAC system and into the
pump, which is filled with oil. Moisture is a contaminant, so
change
the oil every time. With our old system pumps for automotive use,
we changed oil once or twice a year, but they kept working despite
the abuse. The Boss said "It's too expensive to change oil each
time."

I change mine after each use, but the oil gets collected and I let
most of the water settle out. Then it goes through a vacuum
distillation system to remove the rest.

Steve W.

Would it help to pump down with a carbon vane pump before switching to
the oil pump?

Gast recommends running air through the pump for 5 minutes to dry it.
http://www.gastmfg.com/support_docum...oilless_om.pdf

jsw