Where I used to work( I since retired early I took an early retirement from being a supervisor) We had tankers coming in from the mid-west states, Ohio, and Canada. We used to use Hot water on the outlet valve and if that didn't work to open a frozen outlet we used air. Hooked up an air hose with a special fitting an applied over 100psi to open it up. when that let go and shot up towards the front of the tanker it sounded like a gun going off. We also got tankers from the southern states too but the chance they were froze was not great as the ones from Nebraska, Indiana, Iowa, Minnesota, Ohio, New Jersey and Canada .These tankers were loaded with liquid egg and had to be loaded at 33-36 degrees for shipping. In the summer that was a different story as we had spoiled egg come in to the plant. Especially from a plant in Arkansas.. Somehow the tankers were usually loaded and till we got them it was 5-6 days later, I don't know if trucking was the issue or the drivers just didn't care when they got there So you can imagine when you have 48,000-50000 lbs of spoiled egg thats a big loss and depending on the fluctuating market value sometimes even a bigger financial loss. .But I can definably relate to the frozen valve situation. I'm sure you seen tankers from where I used to work on the road. Papetti's and Michael Foods.