how to set up expation valve

[ActiveEngineer]

Looking for a guide on how to set up expation valve for freezer running on R404a

what ihave to do and what tools required to set up.

[Toosh]

Looking for a guide on how to set up expation valve for freezer running on R404a....

what i have to do and what tools are required to set up.

First of all do you know what superheat is

[abet_meneses]

Looking for a guide on how to set up expation valve for freezer running on R404a....

what i have to do and what tools are required to set up.

Are you making some adjustment on TXV while the unit is running?If so you may require a P T chart on R404a.set of gauge analyzer,adjustment tools for TXV,it take some time and considerable field experience in doing the thing.Superheat knowledge is a must.

Good Luck

[icecube51]

a good tip, DON'T MESS WHIT TXV/TEV if you don't now how the work. make yourself an experimental small unit at home,an play a wile whit all cinde valve's.
learn to understand them,and when you now enough about them,lern some more.maybe, and only mabey then,you can think that you can work whit TXV or TEV valve's.

Ice
ps;thats what i did, and still do.

[nike123]

http://ra.danfoss.com/TechnicalInfo/...chapter_01.pdf


http://www.mediafire.com/file/z2hxz3xlzhy/TEV discussion.pdf

http://www.mediafire.com/file/nitrjmtxycz/TXVs - All You Need To Know.pdf

http://www.mediafire.com/file/mawz2txmzti/TXV Installation, Field Service, and Assembly.pdf

[US Iceman]

a good tip, DON'T MESS WHIT TXV/TEV...

Which is my advice also. If the valve is properly sized and installed you should NOT have to adjust it.

[nike123]

http://www.refrigeration-engineer.co...ghlight=adjust

[ActiveEngineer]

Yes i do understand super heat a bit but no expert.

[ActiveEngineer]

Are you making some adjustment on TXV while the unit is running?If so you may require a P T chart on R404a.set of gauge analyzer,adjustment tools for TXV,it take some time and considerable field experience in doing the thing.Superheat knowledge is a must.

Good Luck

Sorry for lack of detail,

Hope this explains better.

System was found to be short of refrigerant so one of the techs adjusted valve in the hope that this would give more cooling.

I have been given the job of repairing the sytem so i have removed all refrigerant and looking to start from Sratch so require some help.

[ActiveEngineer]

Quick Q's

How do i edit my post,

[US Iceman]

There should be an edit button in the lower right hand section of your posts. Click that button once, then go ahead and edit your text as you see fit. When you are finished, you should be able to preview your post or accept it with changes.

[ActiveEngineer]

There should be an edit button in the lower right hand section of your posts. Click that button once, then go ahead and edit your text as you see fit. When you are finished, you should be able to preview your post or accept it with changes.

Thanks US Iceman.

[ActiveEngineer]

Ive looked through the information given and i think i have a fair understanding of how it works but there is still a couple of things i am unsure about.

how much refrigerant to add on start up and what position should the valve be in on start up... fully open, half open ?

[nike123]

Ive looked through the information given and i think i have a fair understanding of how it works but there is still a couple of things i am unsure about.

how much refrigerant to add on start up and what position should the valve be in on start up... fully open, half open ?

Valve should be at its initial position set in factory. To find out what is initial position of your valve you need to have manufacturer instalation documentation where is stated how much turns from end position is factory adjustment.
For most applications that is also best setting. After that you could start your refrigerant charging.

If you have liquid receiver and sight glass, add refrigerant until sight glass is full of liquid and then wait until unit is near design temperature and then adjust condenser air flow (with cardboard or simmilar by covering portion of condenser fins) to about 40°C condensation saturation temperature. Than correct charge for clear sight glass. Only after you are sure that unit is at near design temperature and sight glass is full of liquid you could proceed with adjusting TXV to desired superheat.
If you don't have receiver or sight glass, then charge until you got correct subcooling and then adjust TXV to desired superheat value and again check for subcooling and adjust charge.

Do not run compressor without first charge some amount of refrigerant since it could be damaged by overheating.

[lowcool]

danfoss t series valve is three full turns from the wound in position have used this setting on alco valves as well and is about the same,be sure that system maintains good (i dont know what your design pressures are)condensing pressures in low ambient conditions when using a narrow superheat setting across the evaporator.check out other pages in the forums for similar stuff.youll be right active,have fun

[ActiveEngineer]

System is running on R404a and the desing tempature is -21c.

That would give me a running pressure of 1 bar\14.7 Psi, correct ?.

Will the suction pressure at the evaparator be the same as the suction pressure at the compressor.

[FreezerGeezer]

Whether you will see any measurable difference depends on the length of the suction line, how well it's insulated, and how it's installed (riser lengths & suchlike). All these will affect the heat gain between the evaporator outlet and the compressor suction inlet. Any change in refrigerant heat energy will obviously mean a change in pressure.
And I'm with U.S. Iceman - if the TEV is sized correctly, then a new one off the shelf should be factory set to the correct setting.

[govind]

what's the model no, if danfoss would try to get you the factory setting

[s.m.kadri]

Looking for a guide on how to set up expation valve for freezer running on R404a

what ihave to do and what tools required to set up.

turn clockwise to increase superheat and opposite decrease, in simple , to make it more colder just turn half round,wait and see. pleaase do not rush , good luck. kad.

[lowcool]

be sure tev is matched to evaporator heat load capacity,some adjustment of superheat maybe required as not all evaporators kw ratings fit in to the range of all tev manufacturers ratings.i only carry danfoss and adjustments are sometimes necessary to gain optimum performance fom the system.you can measure td across the evap with thermomemeter but fitting access valve at evaporator outlet for pressure is far more indicative as the valve works.