Can a car aircon thermostatic expansion valve be repaired

[greentech]

I would like to know if anybody in the forum know if a car aircon thermostatic expansion valve be repaired.  Reason, every time a car aircon is being repaired due to leak or the evaporator is being cleaned, they replace the Thermostatic expansion valve, it cost approx. P450 + - . This valve is a mechanical device. with adjustable spring inside. they said it cannot be repaired.