Help please pneumatic tank drivers

First, I take it you are unloading frac sand? You migh have gotten a quick guide and let go if it is like most oil field jobs, earn while you learn. Most pneumatic tankers don't need more that about 1200 in RPM (tach). If you will look on the inside door of where the gauges are, there is usually a rough guide on how to operate the unloading process but either pressure should never go over 17 lbs. Opening the line pressure valve all the way will dedicate more pressure to the line. and the line is what actually pushes the powder/sand out of the 4" rubber hose and into the silo/frac tank.

Closing the same valve (the first valve toward the front of the trailer) will dedicate more pressure into the tank and less in the line. So the tank pressure pushes the sand into the line and the line is what the material flows through. When you open the product valve, open it slow. This is the valve at the bottom of each pod or section that looks like a funnel. If your pressure starts rising fast, shut the product valve off and open the line valve all the way until it clears out then start the process over again.

If you should happen to get the pressure too high there is a pressure relief valve between the blower and where you attach the front 3" hose. It that opens it will dump all the air out of the system right there and it will not start flowing again until you open the dump valve (the valve you open to depressurize the tank at the end of the process). Until you get the pressure down that valve will remain open so get the pressure down a soon as possible and remember that pressure is not all that has to be considered when operating a pneumatic tanker, there is also how much volume of air you are moving per minute. Many tanker driver will insist that giving it all the pressure you can will make it unload faster.

That is not always true. What good does running a high pressure if it causes you to plug things up and have to take 45 minutes to get it flowing again? And if you see the pressure gaining on you, and opening the line valves doesn't get it down, try closing the product valve until the line and tank pressure gets manageable again.

A lot of info all at once I know but you might check with http://www.vantagetrailer.com/home.asp and see if any of this makes sense. Good luck and hope I helped. Also wait until the tank pressure is up around 13-14 lbs before you open the line valve up and because you are just learning, go ahead and open the line valve up all the way until you get the product valve (one at a time) opened all the way and then close the line valve a little to provide top pressure to the tank so it stays pressurized.

 

One thing you have going for you is that sand is one of the easier materials to unload from these trailers. I've hauled everything from hydrate lime (really light and fluffy) to pebble quicklime the size of my thumb. Man... it's a pain when that stuff plugs up in the valve, as you may have to blow the tank down and take the plate off in order to clear it up... after trying to clear it up with pressure, of course.

I'm hauling cement right now, which is also easy stuff, but I'm kinda saving up for a truck, with an eye toward maybe hauling some of that sand. Hopefully those hauls will last a while here in AR.

 

I answered an add in the paper for hauling frac sand and after a little talk with the guy he said I might should stay with what I was doing.

 

We've had a couple companies move in recently, from your neck of the woods and from Oklahoma. In the end, I'll keep my options open and won't make a firm decision until I'm financially ready to pull the trigger.
I do hope there's still lots of work upstate by then, cuz I kinda like driving country roads away from the city.

 

One little note: use the bottom air instead of top air when you start to unload. Top air can cause the product to get plugged but with bottom air it will help to "break up" the product before it goes into the "plumbing" to the hose.
One other tip is NOT to shut the air off or close a bottom valve to quickly as some time fine product will get into the feed hoses and no matter how much you beat on them they don't want to clear. Then it's added time unbolting them and clearing them by hand! Bleed off pressure slowly when tank still has product in it to avoid this problem also.
But ALWAYS watch that pressure gauge and LISTEN to the product as it flows through the hose. Never sit in the tractor or let your attention leave that truck! Also ask for what RPM to set the engine at for unloading. Some engines work best at 1200 RPM some higher. It all can depend on if you are using a PTI or an exhaust system. ASK before you leave with your truck! It's been a few years since I pulled a pneumatic tank but I could jump on one right now and clear the hose with back pressure! Some things you don't forget!

 

x3 on knowing the proper rpm range. The Macks I drove for years did just fine at about 1200rpm on a PTO blower. The Pete I'm driving now apparently has a slightly different setup, and the blower turns twice as fast as the engine.... so I set the throttle lock (no cruise on this old truck) at 600-700 rpms. Works great, and it's a good thing my predecessor went through it with me before he left.

 

We used the hand throttle on the Petes we had to, it worked fine.

My days of hauling bulk cement might be coming to an end, I have cement burns on both legs and I guess it is pretty serious. I'm going to try a product called nutralite and try and get it to go away but I've had it for about two years now and might not be able to take being exposed to cement anymore.

Might have to start hauling flour. The Frac sand hauling is pretty well shot around N. Texas at the moment.

 

I have been running pneumatics for most of the years I've been driving.

Well cover loading, open lids make sure bottoms are closed, pour in the sand. Its good to know your exact tare before pulling into load unless being loaded on a scale. Mine is 24,000 full of fuel. And the loaded goal 56,000 / 80000 gross. 79200 I go back and top off, 79600 or better. Paid by the ton.

Real simple, first Identfy the valve and there location on the trailer, Some trailer may have valve that other do not have, such as a shut off inline between trailers or jet air.

Most of put blower are bottom mounts on the transmission, this set up you will normally run engine rpms 1200 to 1500 rpms.

1. Hook up product hose or hose's (some plants I unload both trailers at the same time).

2. Open line air wide open. (makes sure line is clear before you have a chance to plug it up, always start with line air open, always.

3. Close trailer vent(s).

4. Open (personal preference I don't use top air on sand) airation to pressurize trailer.

5. close line air (all air into trailer) to pressurize trailer up to 12 psi ( no more than 12 psi to start) trailer will gain some pressure as you unload.

6. Open line air wide open to start.

7. Open product valve 3/4, DO NOT YANK OPEN, open at a gradual rate. give it a couple of minutes to stabilize.

8. Watch your gauges, they should stabilize near each other, if your line pressure is to low close the valve 1 notch. give it a minute. The lore you open your line air the lower your line pressure will be. You should be unloading at or near 12 PSI, if you want more line pressure you can also open your product another valve.

When the gauges drop to zero, your done. No product, No pressure.

9. After unloading pop off your hot air hose let blower run a minute or so to cool off, its running temp maybe between 350 500 degrees depending on how hard the blower is working to unload, and the air temp where your working, col down is a good idea. They aren't joking when they call the compressed air line the Hot Air Line it will burn most of us have a few scares even being careful, careful hot.

Cement is a little different, but simular wide open on Product, tank and 3/4 on line air.

If your pulling double alway remove the caps on your product lines before you pressure anything, 2 reasons 1> protects your shin bones, later. 2> gives you somewhere to reroute the air in a hurry, without damaging anything.

We haul cement and sand everyday, but we also haul lime, slurry, 3/8-1/8, hydrate, salt, gyp, iron ore, soda, flyash, 3/8 roofing rock, molasses liquid and chips (different trailer still pneumatic just food grade). Everything but liquid unloads similar, variations on the above, I have a liquid pump on the right side of the truck just for food grade.

If you have question you can PM me.