Here is a well-written LEV guide by Thermatech dated 18 July 2009.

However, I have a question about this part:

If you want to fully remove the LEV valve head from the valve body always turn power to the indoor unit off. The indoor unit will motor the valve needle into shut possition using the 30v dc control voltage.
If you hold the valve head in your hand you can feel it working & know when it has stopped at shut.
At this point the circuit board & you both know that the position of the valve is at shut possition.
Then if you put that valve head on another indoor unit provided you made sure that LEV valve was also fully shut before you removed it then you can do the swap.
Is this because the valve head does not know its absolute position and cannot tell the circuit board its absolute position?

What if the valve head has been removed from the valve body while still electrically connected, and then the indoor unit is switched off? Will the valve head motor to a longer-than-normal-close position? Is this bad?

Does anyone like to share more knowledge about these LEVs used in Mitsubish VRF? In my experience, they are super prone to problems, and also rust easily.

Thermatech mentioned strainers, are they integrated with LEV body?