I expect your correct on that, but what happens to the pressure generated by the pump? If it was being used to pressure the tank to force fuel to the engine, it would always create a positive pressure on the fuel tank with the pressure being relieved by way of the fuel going into the carburetor, but if that line is blocked by a valve, the pressure would continue to build up, somewhat like a balloon under pressure. If not vented or relieved, the balloon will eventually explode and make a mess all over the place. Same thing can happen when a pump is "dead-headed," or pumping into a tank that is full and no way for overflow or to vent.

I don't know about this application, but am somewhat familiar with balloons and pumps pumping and the outlet being valved or blocked off (same effect). I really don' know, but would like to know as there has to be a way of either venting the pressure created by the pump, or turning the pump off. Like I said, I was . . . born in the dark!! LOL! Surly, someone out there has some information. Of course, that information might be with the instructions as it is a pump for a smoke system. I just don't want to spend the money until I know. I'm not real fond of spending my hard earned cash on something like this until I know the details!

Sorry if I have muddied up the water for you. It is an excellent post on a subject that I had some interest in. Perhaps someone with experience using the Perry Oscillating Smoke Pump and Valve will join in the discussion and straighten me out.

I'm just looking for an answer or some insight into the matter before I go out and purchase a set up like this. Gosh, I may be all wet on the matter or making a big deal out of nothing. If so, someone please tell me! I'm just kind of fond of getting the lesson before the test, not afterward!!

"Experience is a hard teacher. She gives you the test first, and the lesson some time later!"