sorry to post another walk-in cooler problem here,but hoping for some help here...
keep in mind i mostly do residential work

outdoor condensing unit:copeland model#F3AH-A100-CAV-001
indoor evap. unit:BOHN model#adt070ak
indoor txv:Sporlan KT 43 VC
76.4 F outdoor temp
38 F inside cooler temp
suction pressure:49 psi head pressure:200 psi
suction saturation temp:25 head saturation temp:100
suction line temp:47.3 head line temp:91.4
**unit uses a thermostat set at 36 F**
problem is, as you can tell the superheat is way high and over a period of a week the indoor coil is frozen up solid. I've tried adjusting the txv in both directions from factory settings and the best I can achieve is 20-22 superheat. Tried to adjust it by adding and taking away freon (oh yea i forgot to mention it's a R-22 system), finaly got frustrated and recovered all freon from system and recharged until site glass just was clear and then tried to adjust the superheat yet again by the txv with the same results. Any help with this situation would be greatly appreciated. If I have left out any needed info. please let me know.