My Water Well pressure control switch is different from the one shown in the picture - it has only one spring loaded post, below which is two rows of four screw adjusters - it is made in China - do is use one of the screws in one of the rows to adjust cut out pressure? The cut in is 20 psi - it apparently cuts out at about this pressure. I want to up it to 40 psi - what screw do is use? If you have a picture, it would help! William Gish

Don't see a picture, but you would probably want to turn the nut on the spring loaded post clockwise to adjust pressure up. It will maintain roughly a 20# differential between cutoff and cutin pressures. Be aware that a quarter of a turn doesn't accomplish much. Start with two or three full turns, then let you system cycle to see what that accomplished, and go from there. Good idea to turn off the power when you're turning that nut.

Not sure I understand how it can cutin at 20 and cutout at 20. Do you mean it is presently cutting on at 20 and cutting off at 40?

The four screws you referred to sound like the terminals for power coming in and going out, so I'd tend to avoid them. The only pressure that would raise would be your blood pressure if you touched one.