Testing, testing,1,2,3

[fridg]

Well i have recieved a fridge on R134a ,Fan forced evap
induced fan condenser. It is a commercial shop fridge.

It is a project at home, i want to fit schraders and service valves to the system to read pressures at different points at different loads.(yes i am in the trade)

Any thoughts where you would put them ?

ANY IDEAS ?

1st year apprentice.

[Edited by fridg on 10-23-2005 at 04:08 AM]

[rayr]

If this is a household fridge you are leimited to only a couple of places. Hot gas line near compressor, liquid line before metering device, and maybe the suction line leaving the evaporator if it is not aluminum. Do NOT use line taps. Cut the line and braze in a tee with a schrader fitting in it. Be sure to use a nitrogen purge, remove the schrader, change the drier and evacuate. keep in mind that these fridges hold only a small amt of refrigerant removing the hoses frequently you lose will lose enough refrig to change the operation. Low loss hoses should be used. GL

[fridg]

Thanks rayr !

No it is not a household fridge it is a display cabinet from a shop.

Also i work in the manufacturing of like cabinets so parts are dirt cheap.

So come on guys throw your ideas at me
i need inspiration

[frigetater]

instead of opening up the system and soldering in fittings I haved used the saddle type solder-on fittings that allow you to tap in without a leak. just keep the line cool as possible.

[R12rules]

Originally posted by frigetater
instead of opening up the system and soldering in fittings I haved used the saddle type solder-on fittings that allow you to tap in without a leak. just keep the line cool as possible.

This is the right way to go. It allows you to tap in but not disturb the charge.

I would do this project in such a way as to leave the gages on ... for good. Copper tubing in place of hoses.

And I would attach temp sensors to various parts of the system to measure what is going on with the refrigerant.

I might even wire in a light bulb to simulate a load ... inside the cabinet.

If you care to get creative, you can install several citcuit of metering devices.
One circuit feeds the original cap tube.
Next circuit feeds a txv. Next feels an AEV. Next feeds an electronic valve.

You can pick and choose which one you wish to feed the coil with at a particular session for viewing the results.

Each one however, will require you to have the system with a specific charge of refrigerant.
This could lead to some real fun.

[cascader]

I like soldering thermocouples to all the key points,and to tweak the charge too.

[fridg]

R 12

I'm thinking on the same lines as you have 4 or 5
different systems in the 1 !

Tx, cap tube, float type controls.
the later being hard as it has no bore but maybe, used in conjunction with a reciever it might work.

A control to isolate different parts of the system (eg)(compressor,fans,flow controls,lights,relays)

Also maybe a series of sight glasses in the evap and condenser to show the flashing off of the refrigerant.

[dogma]

i like i like. Dude check this out. when you get your manatowc crimp tools....cut and weld in a reciever with valves.

Then you can pump it down cut and shut where you like..

You'll still need to overcome the vac issue but remember that dick from York?

[fridg]

Yep what a jerk works for a big company and cant even charge a roomie


AND FORGET TO EVEN VAC IT !!!!!!

Them tools will be handy you will have to try em out
see if you like !

[R12rules]

with modern plastics, you dont have to use sight glasses anymore.
You can obtain hi impact plastic tubing, small inside diameter, and fittings in order to place the tubing pieces in line with the refrigerant flow.

These will give you the window needed to see what is actually going on inside the sealed system.

But do not brase any joints once the system has been started up and ran.
Once you light a torch you can flash the oil inside and burn out the plastic.

Had a prof in college who commisioned a frige to be built using glass tubing as much as possible.

Ten one day a student in his class lit a torch to make a repair, during scheduled times ... no nitrogen ... ooops.


so ... if you do this ... always use nitrogen to brase and purge out the oxygen. This will prevent flashing and potential "smoking" of the hi impact plastic tubing.


I have given this MUCH THOUGHT ... ask if you have questions.

[fridg]

R 12

Is this plastic tubing able to hold high pressures
300 kpa on the cpr to the comp
acrylic is it or nylon ?


Are these plastics to refrigeration standards.

YOU GOT BRAINS R 12 !!!!!

[rayr]

Originally posted by fridg
R 12

Is this plastic tubing able to hold high pressures
300 kpa on the cpr to the comp
acrylic is it or nylon ?


Are these plastics to refrigeration standards.

YOU GOT BRAINS R 12 !!!!!

BOSS really hates "FLAME WARS"----------an execellent way to be banned from the site.

[fridg]

Please explain to last post , what does it mean , point me in the right direction.


INSULT i got it but !!

SORRY BOSS FLAME WAR.

Can these pipes be used for what i want to do
i have seen acrylic pipes at my college
but they have minimal refrigerant in them, not enough for a system to work efficiently.

[Edited by fridg on 10-28-2005 at 06:19 AM]

[dogma]

Same fridg. The systems I've seen with glass pipe work have run on R11 and/or the suction runs in a vacuum.

I think it was a valid Question but...........?

[Wild Leg]

I have a trainer with short sections of clear tubing placed throughout the system, and cut into the coils.
They are covered with a second layer of plastic.

It contains about 3 lbs of R-12.

It runs pressures to produce temps found on an A/C.

It is equipped with a HPCO.

It was sold by Carrier.

It is UL listed.

[dogma]

Ok. So these systems can be easily made in the workshop.. cool.

Where would some one like me find this plastic tubing and what would I be asking for???

For my purposes it would be good if I have the header and end loops made from this.

Sight glasses would suffice any where else. no?

[R12rules]

I would write down what your operating pressures are going to be then I would solicit the assistance of a plastics specialty wholesaler in your town.

If you require the research to be done, like they dont know what to recomend for your project ... then come call me and I will gladly do your research for your project.



I never saw anything resembling a flame war in the making.
Guess it just passed right over my head ... :D

Not the first time anything flew by me on this site:)