A Tanker Question - Pressure Issues?

Last night I was at a well and the truck in front of me was having problems loading. The belly valve was open and all valves that needed to be were open.

He was still getting a lot of back pressure and his vapor recovery was not putting out any air. We tried revving up the engine. Not much help. We tried stopping the pump and the pto. No help. We tried opening and closing the main belly valve. No change. Eventually the tanker was loaded after about an hour. It usually takes 35-40 minutes. Also we couldn't get any suction to empty the hose. It all went in the pumpkin.

When the driver got to the refinery another driver said that if we had released the trailer brakes and reapplied a few times it would have fixed the problem.

I remain skeptical.

I would like to hear what others have to say.

 

I still don't know what the problem was with that trailer. I did find out that if the parking brake is set on the trailer and there is an air leak on the trailer it will disable the belly valve. That could be what the driver at the refinery was talking about.

I have decided I will no longer set the parking brake on my trailer while loading. We have wheel chocks as part of our jsa anyway so it can't hurt anything to do it that way.

I didn't mention it in the op but the other driver and myself were a little nervous about continuing to load that trailer with all the back pressure and no air coming out of vapor recovery. It doesn't take much pressure to cause a lot of damage and injury. I once saw a tire repair guy nearly killed when a 25 psi lawn mower tire exploded in front of him. I don't know how much pressure the pump on a tanker puts out but it sure sounds like it's a lot.

He shut it off at 165 bbls and I haven't seen him since the refinery that night so I don't know if he found out the problem or not.