The builder installed a utilitech (mod# lpt36s) hydro-pneumatic pump pressure tank in our well sys. Does this pressure tank have a blader in it?

Does it look like this one?

WellSaver 36-Gallon Pump Tank (http://milo.com/wellsaver-36-gallon-pump-tank)

Yes it does.

does it look like this one?

wellsaver 36-gallon pump tank (http://milo.com/wellsaver-36-gallon-pump-tank)

Yes it des.

If the tank has a air valve on top then you have a bladder tank. Good luck, TRom

I have a new tank and pressure switch, using old check valve. When the water runs and the tank pressure drops to about 35lbs (its a 30-50) the water stops flowing and the pressure drops to zero for a few seconds and then kicks back on. Do you think the pressure switch turn on setting is off and do you think the check valve is faulty?

Check the pressure at the top of the tank. It should be set at 28# with the pump turned off and pressure drained to zero by opening a faucet. Do this first and see if that helps.

The checkvalve would seem to be good since, as I understand your post, the pressure holds OK when no water is being used.

The switch would also seem to be OK. It should be turning the pump on at 30# or so and off at around 50#.

Is your pump above ground or in the well?