A/C O-Rings?

Ok, I just took the line off that goes from the condensor to the evaporator and I dont see an orifice tube in there anywhere. Is it possible that its not even in there? Does it need to be in there? I have a new line and a new orifice tube but I dont want to put the tube in if its not supposed to be there.
 
Alright! Sheesh! This A/C is killing me. I installed the new accumulator/dryer and new liquid line today and the damn thing holds a charge for about an hour and then it starts cycling like crazy and gets warm. I've got all new o-rings at all the obvious connections. I've also got a new discharge hose as well, I bought that last year. Looks like I can see a little oil where the pressure switch screws onto the schrader valve on the dryer but other than that I see nothing. The pressure switch has no o-ring or anything, does it just seal around the plastic threads? Any other ideas because im lost? Maybe i'll just bring it somewhere and tell them to call me when it holds a charge for more than a millisecond.