I know this is an old thread, but someone might find this useful.
If your using a small compressor (out of a small fridge) for your diy project you should buy an unloader valve that is not delayed. I found that the majority of pressure switches come with delayed unloader valves (unless you specify otherwise). This style of valve won't close until a set pressure is achieved. This feature is to take the strain off the starting motor. The smaller compressors just can't reach the pressure and continue to leak air. I had this problem with my Condor pressure switch. If I held my finger over the air hole until pressure reached about 30psi the unloader would close and work normally. This was only a problem when the tank was completely empty as I set the cut in pressure to 50psi. Once I replaced the unloader valve with an older style valve it closed instantly when the compressor started. If I had known about this when I bought the pressure switch I could have bought the right valve in the beginning.
If your using a small compressor (out of a small fridge) for your diy project you should buy an unloader valve that is not delayed. I found that the majority of pressure switches come with delayed unloader valves (unless you specify otherwise). This style of valve won't close until a set pressure is achieved. This feature is to take the strain off the starting motor. The smaller compressors just can't reach the pressure and continue to leak air. I had this problem with my Condor pressure switch. If I held my finger over the air hole until pressure reached about 30psi the unloader would close and work normally. This was only a problem when the tank was completely empty as I set the cut in pressure to 50psi. Once I replaced the unloader valve with an older style valve it closed instantly when the compressor started. If I had known about this when I bought the pressure switch I could have bought the right valve in the beginning.
