Danfoss TXV Vs. Alco TXV

[maxmejia]

This thing happens to me twice, the latest one:
I have a really big walking frezeer (20 tons. -20°C, R-404a). I started with Danfoss TES20 TXV (power element 067B3352) in the evap . It was taking to long to reach the conditions in the walking f, when I check the SP was very unstable range. After a long time I decided to change the TXV for Alco with the same caracteristic and Bingo, every thing is working fine.
What I am missing about Danfoss?

[BESC5240]

Hi,

could you give some more details on the plant
- 1 evap/1 comp ? several evap/1comp. ? several evap / rack ?
- compressor type ?
- evaporator capacity (kW, dT)
- orifice size ?
- design conditions ? (roomtemp, To, Tc, subcooling ?)
- start-up conditions (roomtemp, To, Tc, subcooling ?)
....

Unstable suction pressure (unstable behaviour) of the expasion valve could be a sign of an orifice that is too large.
My experience is that Danfoss orifices , although of the same 'size/tonnage' as competitors, can handle bigger capacities. I had the problem resolved by putting in a smaller orifice.
(I know in a TES20, there is only 1 size, so a smaller TES12 could do the job).
I avoid making a selection based on the 'nominal size/tonnage' of an orifice.

[nike123]

This thing happens to me twice, the latest one:
I have a really big walking frezeer (20 tons. -20°C, R-404a). I started with Danfoss TES20 TXV (power element 067B3352) in the evap . It was taking to long to reach the conditions in the walking f, when I check the SP was very unstable range. After a long time I decided to change the TXV for Alco with the same caracteristic and Bingo, every thing is working fine.
What I am missing about Danfoss?

Small valve (if all refrigerant is going thru one TEV)!
Unstable SP (hunting) indicate that Danfoss valve is too big.
Nominal capacity of TES20 at -20/35°C is 48 kW (13,7 tons).