Vacuum pumps

[mick2me]

This pump is sold by Ryan Aircon Supplies who advertise on this site.

http://www.ryanairconspares.com/prod...ufacturers_id/



Anyone use this pump or who can comment on it?

[Peter_1]

looks like the Yellow Jacket we use
http://www.sca-australia.com.au/cata...cuum_pumps.php

[Brian_UK]

You're getting more and more involved in your project now Mick, enjoy These pumps are ok but if and when you buy one don't forget to get the oil for it as well.

[mick2me]

You're getting more and more involved in your project now Mick, enjoy These pumps are ok but if and when you buy one don't forget to get the oil for it as well.

Yes Brian, but there does not seem to be a guage on these, unlike peters example?

[Brian_UK]

I'm not sure about the quality of the gauges fitted to those pumps so can't really comment - however - in most cases you will find a recommendation to fit the vacuum gauge to the item being evacuated and not at the pump.

A good quality electronic vacuum gauge will set you back about £125.

[Andy W]

I prefer an Edwards medical quality torr gauge, quite expensive but mine is over 10 years old now, a mate of mine is on his third electronic gauge in 5 years.

[Andy]

I'm not sure about the quality of the gauges fitted to those pumps so can't really comment - however - in most cases you will find a recommendation to fit the vacuum gauge to the item being evacuated and not at the pump.

A good quality electronic vacuum gauge will set you back about £125.

Vac gauge should be fitted furtherest point away from the vac pump

Kind Regards Andy

[mick2me]

Vac gauge should be fitted furtherest point away from the vac pump

Kind Regards Andy

I don't doubt this is the correct method, Andy.

But could you explain the reason for this, assuming pressure througout the system must be pretty equal.

The only thing I can think is to avoid fluctuations on readings due to proximity of the pump?

[bebad]

i think Andy meant whilst in the process of evacuation, not once all valves are then closed, it woulndn't matter where you place gauge then, have to agree BOC Edwards do great mechanical gauge, electronic are troublesome, the price would suggest otherwise though.

[bebad]

origional point raised; I too have had above vacuum pump for 7 years+ regular oil chnges still going strong never let me down, allthough thinking bout it have two robinairs about the same age and they aint give me grief either

[mick2me]

allthough thinking bout it have two robinairs about the same age and they aint give me grief either

ROBINAIR Cooltech high performance vacuum pump model 15225 just went on ebay for £64.50

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ih=020&item=300005689498

[Larry2]

Is there any disadvantage other than evacuation speed from buying a 1/6 HP two stage pump vs a 1/3 HP two stage pump? I'm looking at inexpensive units on eBay. Being practical about the time involved, if one will leaves the pump evacuating the system overnight, is there any performance difference at all? The smaller unit is lots cheaper and lighter.

[mick2me]

Is there any disadvantage other than evacuation speed from buying a 1/6 HP two stage pump vs a 1/3 HP two stage pump? I'm looking at inexpensive units on eBay. Being practical about the time involved, if one will leaves the pump evacuating the system overnight, is there any performance difference at all? The smaller unit is lots cheaper and lighter.

Yes I was looking at these as well

1 stage pumps are also available,
What is the benefit of a 2 stage pump over a 1 stage pump?

[US Iceman]

What is the benefit of a 2 stage pump over a 1 stage pump?

If I get this wrong, someone will surely correct me.

The pumps I used to use were two stage with a gas ballast. When you first start the evacuation, you open the gas ballast valve to quickly pull down the vacuum in the system.

After the vacuum gets down to some value (don't remember at the present), the gas ballast valve is closed.

Then the pump is running full out.

I believe the two stage pumps will pull a deeper vacuum quicker.

[Mickvee]

Yes 2 stage vac pumps pull down to a deeper vacuum. I was told that if you use a large CFM vac pump on a small system it can pull down a vac so fast that any vapour in the system freezes due to the deep vac.

[mick2me]

Yes 2 stage vac pumps pull down to a deeper vacuum. I was told that if you use a large CFM vac pump on a small system it can pull down a vac so fast that any vapour in the system freezes due to the deep vac.

Not being an RE, this sounds like a bad thing to me?

[JAGw]

Vac gauge should be fitted furtherest point away from the vac pump

Kind Regards Andy

How do you remove this Vac gauge without a spill or contamination?

JAGw

[Larry2]

[QUOTEHow do you remove this Vac gauge without a spill or contamination?

JAGw][/QUOTE]


One way would be to add some refrigerant pressure from the other end of the system until you had somewhat above 0 PSIG. Then detach the gauge from the low loss fitting and apply the brass cap. Minimal loss and no contamination.

[aawood1]

Hi as I work on Ammonia systems the way that I use, is to fit a service valve before the vacuum gauge, That way you can shut the valve and remove the gauge and then cap the outlet.
Arthur

[Larry2]

Does anyone have experience with FJC vacuum pumps? I'm considering purchase of this small two stage unit.

http://www.thetoolwarehouse.net/shop/FJC-6908.html