how to warm up a centrifugal

[bluke1]

I need to do an oil change on a CVHE. There is no hot water available near the chillers, so I need to find a portable water heater solution to warm the barrel. Preferably without taking 6 hours. Anyone have a piece of equipment they recommend? I think a propane heater would work the best, as the only power sources nearby are 120v or feeds equipment. Thanks.

[york56]

http://www.westsidewholesale.com/plu...osch-rp7p.html

You could mabey use some thing like this just a thought.

[Tech Rob]

You don't need to pressurize a low pressure chiller to do an oil change. You can do it in about 30 minutes with the machine in a vacuum if you've got the right tools.

[R123]

You don't need to pressurize a low pressure chiller to do an oil change. You can do it in about 30 minutes with the machine in a vacuum if you've got the right tools.

AGREED!

I have never heated up a low pressure chiller to do an oil change and it takes me 30 minutes with minimal tools.

[york56]

The real simple way is to start the machine get it down to 45 deg. chw nice vacumm shut it down and work on it. You need to be quick about it.

[behappy]

How do you warm up a chiller

Kiss it gently and tell her how much you love her.

[Tech Rob]

One of the guys who used to come on this board had a 123 refrigerant drum that he converted to a vacuum chamber with isolation valves on the inlet and outlet. He would evacuate the drum to a pressure lower than the chiller, open the isolation valve, and it would suck the oil right out of the chiller. Use the vacuum in the chiller to draw the new oil in.

[york56]

Invest in a good gear pump and your troubles will be over.

[Nuclrchiller]

Invest in a good gear pump and your troubles will be over.

+1.

[R123]

We also use an oil transfer pump.

[ga1279]

bluke1 - Okay here it is, no hot water generation needed only 120 volt outlet. From the sump valve on the oil tank connect a 1/2" refrigerant hose to a gear pump inlet side with a check valve on the discharge side to prevent back flow. Leave the sump valve closed at this point. Install a line from the check valve outlet with a sight glass on the end and connect to a vacuum pump, if you have any ball valves that would help. Start the vacuum pump and once the vacuum drops below the level of the sump pressure open the sump valve and watch for oil moving to the sight glass. Valve off the sight glass, shut off the vacuum pump and start the gear pump and drain your 7 gallons into a 100 # refrigerant can (now a waste oil drum) . This doesn't take long, but once your pump looses prime your done. Your can either suck the new oil in or valve off the sump and reverse the gear pump and pump the oil back in the sump. Just remember to purge the air out of the connection at the oil sump before opening that valve. I always pump the oil in as I know I won't get air in the sump. Good luck- GEO

[bluke1]

Thanks for the advice. I have researched the question before I asked here. The local trane office told me that their method was to warm the chiller. I have searched gear pumps, but most seemed too large, high gpm. Can anyone be specific on the manuf. and model of the pump you are using?

[ga1279]

bluke- You don't need a high dollar hydraulic oil pump, I have a 1/2 hp, 120volt pump that came from W.W,Grainger. Yes, it is preferable to heat the entire vessel up as then you can also do a leak check. bluke please remember though you ask for advice and got it. The guys on hvac-talk.com have years of experience doing this and have been in your situation long before we had this easy method of getting professional advice. I have almost 30 years myself and I still request information from others. Like the man said "Ain't none of us as smart as all of us". I am a professional technician in training and will be for years to come. Good luck -GEO

[Nuclrchiller]

Back in the days of R11 I used a small, one-piece pump that I believed was intended for "pool duty". It had a direct drive rubber impeller. It worked fine until R123, and its lower pressure, appeared on the scene.The vacuum in the oil sump was to great for that pump to overcome. Then I bought the smallest coupled gear pump (and motor to drive it) that I could find in Grainger's catalog. In 25 years those were the only pumps I used for that purpose. Although that little pool pump got to where it would sometimes spark pretty good while running! lol, ahhh, good times.

[rscamaro]

I might have a co-worker who uses a gear pump off of a generic small oil burner. He may connect it with a standard 1/2" drill and whatever fittings that are necessary. Of course I can't recommend this type of home made contraption but it seemed to work well enough from what I've seen. It easily overcomes the vacuum on a low pressure chiller.

...Ron

[york56]

Find a good Industrial oil fired boiler thats being demoed and if there is one piece of salvage that you want its the gear pump for that boiler the rest is up to you to modify it to your personal spec's.

[bluke1]

Thanks, guys. I'm in Oklahoma, where natural gas is king. I've never personally laid eyes on an oil-fired anything. I will likely buy both a pump and portable heater, both are good to have and the boss is willing to buy whatever I need. I appreciate all your input.

[supertek65]

providing that the chiller is off?

just turn the chilled water pumps on for a while!

i accidentally left a pump in hand last night to a 410a chiller.
went back this morning and here is the result!

[Tech Rob]

If you've got a big domestic water boiler and storage tank near the chiller, you can run some hoses from that tank, in and out of the chiller, and right down the drain. Don't need any more than 2-3 GPM flow.

[Tech Rob]

providing that the chiller is off?

just turn the chilled water pumps on for a while!

i accidentally left a pump in hand last night to a 410a chiller.
went back this morning and here is the result!

Did it pop the relief valves?