Pneumatic Tankers ?

That place must have had a limit as to the amount of pressure the tanks could be unloaded at.

One place I used to unload at made us install a pop off valve on the blower so that we wouldn't go over 4psi instead of the usual 8-10 I'd unload at.

Also, when/if the material clogs up, it'll make unloading longer due to the clean up.

Here's what the pop off valve I had to use looked like:

 

Cement tankers usually come in two configurations...the one most seen is the one that looks like a pig with three cones out the bottom. These are the most lightweight and the lowest to the ground height wise. The other is an older style that looks like a fat thermos bottle with cones out the bottom. Both are good trailers and are operated in the same way. The difference...weight.

My "Pig" trailer is capable of hauling 29 tons of cement or flyash. We can haul 84K in Texas with an overweight variance permit...just not on the interstate. My "Thermos bottle" trailer only allowed me to haul 28 tons.

I might add that my tractor is a daycab Freightliner Columbia and is very lightweight.

Both trailers I pulled were made by Heil and were piped pretty much the same...you'll find differences in piping from trailer to trailer as well as the number of dome lids.

That said...I DO haul cement and flyash for a living.

My "Normal" unloading time at 12.5 to 14 PSI varies from just over a half an hour to as much as 1 hour 20 minutes...it depends on the height of push to the top of the silo more than anything else in my experience.

My half hour times are for horizontal pigs at portable cement plants where there is little to no height at all. The hour 20 minute times are for a cement transfer plant silo that has 120 feet of vertical push to the top of the silo. The transfer silo is a real tricky blow off because of the 120 foot lift you must overcome...pressures get out of hand quickly and hose stop-ups are common if you're not paying attention closely.

With all the above in perspective...dry products can also get "Fluid" on you in a hurry in a turning or stopping situation...in otherwords...it WILL shift on you in a hurry if you don't drive smoothly. The trailers ARE topheavy when loaded, so...Always watch your speed on off and on ramps as well as turns where you might lose a set of tandems in a small ditch.

As with all things "New" in your trucking life...Get training...hauling pneumatic trailers is easy, but can be a bit tricky if you're just getting into it. Have an old hand show you the ropes...you'll be glad you did.

 

anyone know a few companies that run those things in the southeast TX area. May be something I'd like.
the guys I was watching were pumping way up into a silo

 

pm'd you medicine man, hope it helps...

 

This was a pretty standard silo that I used to unload into.

 

Medicine Man, The best thing I can tell you to do is look around at your local redi-mix plants and see who hauls their cement to them. Many have their own in-house trucks and others hire it done.

We've got three cement manufacturers in Midlothian, but most other outlying places use a loading transfer point and have it shipped in by rail.

Our outfit runs a lot to Tyler and Longview from Midlothian.

Good Luck.

 

pretty much as posted, it takes me 1 hour most loads, hour and half on silos with bag house unloading at lower pressure. the testy part is when you have a stoppage and have to pull the pipes loose on the bottom and unplug it. never happens on a cool slow day, always hot and running behind.lol about only time i stop up is when ash gets past the valves and fills the pipes while going down the road, and pressure won't blow it out.

i like my job pretty well. yes the powder will shift if you are not smooth, and it is a little top heavy, but not as bad as a mixer full of concrete on a wet spot and one side sinking in the ground, now that will draw ya up some, make ya scared to stay in and scared to get out.lol

i haul 25 ton with a ch613 day cab, gross 79800 or so.

 

Really, the thermos bottle tanker I pulled was taller. The first "Pig" style I pulled was tall as well. The newer the trailer, usually the shorter it is...they're are exceptions, but for the most part that holds true.

I latched on to my current trailer when one of our drivers couldn't operate it properly. He was running his blower too fast and constantly popping off the relief valve...he pronounced it "JUNK". Can you say..."Dumber than a box of rocks"????? It's air ride too!!!!!!!!! My old tank was spring ride.

 

Never, never, never disconnect the product hose if you plug up! Absolutly no reason to! If you plug up keep the blower running. Completly open the line air valve, Open the blowdown/ trailer vent valve and then open and close the product valve about once every 3 seconds.

Keep opening and closing the product valve. When the plug clears you may see the trailer jump!

This will suck the product back into your trailer. Not all of it just whats in the pipe.

Also never turn the blower off with pressure in the trailer. The product can back flow and ruin the $4500 blower.

As for unloading time. Pads are much faster than cones. I used to unload 50K of Powder Cement in 40 min with pads. Cones took 55 min.