Tanks watching this question.

First I'm sorry my English uncomfortable.

I saw that "The refrigerant relief valve must be connected in the discharge line between the
compressor and the shut-off valve." as Fuller rotary compressor.

In my common sense, Relief valve can not working flow low pressure to high pressure side.

How can work that relief valve?

Or Has some different suitable relief valve?

Newbie Grateful waiting for your answer.

Booster_Relief_valve.png