Pressure Relief valve location

Can a pressure relief valve for a submersible system be located inside the well casing? According to what I have read, the PRV needs to be able to handle the full rated pressure at the outflow volume. Wouldn't this need to be as big of an opening as the supply? I am looking at about 18GPM which would flood a pretty good sized area. If the relief was in the well casing, the water would just flow back in and rercirculate.

It's very rare that a PRV ever goes off. The pump not coming on is a much larger problem than the pump not going off. If the pump is properly sized to the application, a PRV is seldom necessary even though code calls for one in a lot of cases. Most bladder tanks are rated for more pressure than a sub can make. I'm not sure why you would need one that will discharge the same as the pump can output. Since it takes more than 75 psi to make one blow, it's going to take the same 75 psi to keep it open which will hold the pump back a lot.

bob...