The Pneumatic Tanker Thread

Thanks! I also like the green on the Heil trailers. I was hauling PET plastic pellets. Check out these pictures of our companies show truck. The trailer looks really cool. Next time I see it in the yard I will have to get a better picture of the trailer. That is the same truck in both pics. Just different paint jobs

 

Nice

 

One of my coworkers had a very bad night last week. His truck was in the shop for some repairs, so he used a spare. The spare that he used is a 2015 Coronado with 125000 on the odometer, so it's fairly new.

He goes to deliver his first load of the night and blocks the trailer. He tries unblocking it with no luck. Pop off valve screaming away, the blower gets hot, melts the heat plug. Now he's unable to do anything with it. So he goes to shut down the blower, which has pressure in the hot hose. He flips the switch to turn the pto off, and it stays running. So he does the one thing I've always been told not to do. He pushed the clutch in, stopping the blower instantly. Which wiped out the gears in the pto.

Meanwhile another truck comes along, and tries to finish unloading the trailer, to no avail. Turns out, the check valve on the trailer failed, and would not let air through it. So they call our mechanic, who brings a check valve out at 3am. They get the trailer empty, but now we have a truck still sitting with the pto stuck in gear. So they remove the pto shaft, and drive it home with the pto in gear, grinding away what was left of the gears. Pieces of the pto gears ended up in the transmission, and eventually wiped the transmission out.

So our spare sits awaiting a new pto and transmission.Total bill for all this looks to be around $6500. Needless to say, the boss isn't too happy with my coworker..

 

I put the truck in gear before engaging the PTO. That stops the transmission from turning. And I was when disengaging the PTo to just flip the switch to turn it off. The reason I was given was kind of proven in this case. Theory is if there's pressure in the line, and you push the clutch in, the blower will stop very quickly, and cause damage. By just flipping the switch to disengage it, it won't come out of gear until there's no resistance. Which would let the blower slow down gradually.

The check valve was the original one from when it was new in 1999.. So I'd guess it was just it's time to fail

 

Maybe could've turned key off and would've let everything slow down, not as instant as just pushing clutch in? Or take a couple pieces of rope or string or something and break cam locks loose on hot hose while at a safe distance and then shut down blower?

 

Maybe your trailers are set up differently than ours but why could he not have just opened the blow down valve to release some of the pressure and then turned off the blower? If my line plugs I always open the blowdown bump the clutch so the blower goes to idle speed, wait for the pressure to go down then shut off the PTO

 

We think when the check valve broke internally, it pushed the flapper inside up against the pipe, which didn't let air through. And the air goes through that check valve before anything else, if that makes sense. So just opening the blowdown wouldn't have released pressure there.

 

I see, so there was no air even going to the tank. Do you not have a pop off valve on the blower? I would think the pop off on the bower would open right away and he should have shut down the blower right away. If that pop off opens right away you know something's wrong