If you attend a drag race, do you walkdown from the stands, climb behindthe wheel and run a top-fuel dragsterdown a quarter-mile straightaway infour or five seconds at 320 miles perhour?

Not likely, and certainly not withoutproper training with the powerfulmachine you are operating. Yet some-thing similar happens ever yday as vacuum truck operators man high-per-formance trucks, sometimes with limitedknowledge.

Why is it that two operators can per-form the same job with the same truck,same age, same style, and achieve twovery different results? Chances are thatonly one is making best use of his equip-ment under the proper conditions and inthe safest manner to maximize what thetruck can do. That operator is saving hiscompany time and money with greaterefficiency.

Most truck operators do not havedegrees in physics, nor should they.However, unless they understand somefairly basic principles of physics, theycannot make the trucks perform at peakefficiency, and they may put themselvesin very real physical danger.

Staying ProductiveProductivity with vacuum trucks is

critical. Here are a few key points everyoperator would do well to keep in mind.They are not all you need to know, but Ialways stress them in my seminars.

1. Hose diameter is very important.Operators need to understand the

importance of changing from one hosesize to another and the impact of theirdecisions. Just how much impact can aslight change in diameter make? In semi-nars, I show operators the differencebetween a 1/4-inch hose and a 3/8-inchhose. I connect each hose to a mustardjar and see how quickly each jar loads.You might think that since the 3/8-inchhose is half again as large in diameter, itwould vacuum the contents 50 percentfaster than the 1/4-inch hose. Instead, the jar loads nine times faster with the3/8-inch hose!

2. Hose diameter is also para-mount in getting the most out ofyour truck.

Changing hose diameters along thelength of the suction hose is not only inef-ficient it can cause hoses to stop up. Ifyou start off with an 8-inch hose that theoperator runs 100 feet, and then changeto a 4-inch hose, the speed of the air atthe start of the 4-inch hose is deafening.The truck is being asked to suction anamount of air designed to go into an 8-inch hose at full throttle, but only througha 4-inch opening. The material fliesthrough the hose at 4 inches. Then, when

it enters the 8-inch section, the speed ofair is reduced, and material clogs up thehose. This is a very common mistakeoperators make.

3. Performance decreases as fric-tion loss increases.

Hold a 7-inch-long hose with a 1/4-inch diameter to your mouth and try to

blow through it. Not difficult. Then try todo the same with a 7-foot length of thesame hose. Your eyes will probably bugout trying to push air through to the otherside. This gives you some idea of howhard your machine has to work. It doesntmatter if the air is being sucked or blownthrough a hose, it still suffers from frictionloss.

4. Smooth-bore hoses almostalways work better.

Drainage system polyethylene hose isa corrugated pipe that is lightweight andeasy to handle, but long lengths of thishose/pipe can devastate the perform-ance of your truck. An operator can getby with a drainage system hose on ashort job, but on a longer and tougherjob, a smooth-bore hose may be neces-sary. The majority of your hose lengthshould be smooth-bore pipe or rubberhose. Only the last section of hose at theworking end could be the lightweightpolyethylene corrugated hose.

Staying safeSafety is just as important on the job

as productivity in fact, even more so.Unfortunately, I see many of the samemistakes and same problems today as sixor seven years ago, especially with new

operators. Here are a few vacuum truckssafety points to keep in mind when onthe job:

1. The tank is a confined space.An operator may be handling toxic

chemicals. If he enters the tank to make arepair, he might be overcome by fumes.There is only one way in and one way outof the tank, so it is a confined space in thetruest sense. Dont enter a tank whenthere are chemicals inside.

2. An inline T and vacuumrelease can help ensure safety.

There are three release areas avail-able with a truck, including a remoterelease, a manual release near the truckitself, and an inline T. I believe all threesafety releases should be standard equip-ment on vacuum trucks. The larger thediameter of the hose, the bigger the forceyou have. If an 8-inch hose gets stuck toyour body at 27 inches Hg, it can be fatal.An inline T is the mechanical deviceplaced in the hose that kills the vacuumin the hose.

Injuries also occur because someusers do not install the in-line relief andmay be working too far away from thetruck to quickly access the pendant(remote) or manual relief on the truck. I

Back toBasics

Keep these key points in mind and youllincrease safety and productivity in your vacuum truck operations

By Phil Stein

Its highly recommended in vacuum operations to have two hose handlers working together to relieveone another during the job.

Safety is just as important on the job as productivity in fact, even more so. Unfortunately, I see many of the

same mistakes and same problems today as six or seven years ago, especially with new operators.

recommend thatthe in-line T beinstalled betweenthe very last sec-tion of hose andthe working sec-tion of hose. Thecord that releas-es the in-linerelief should betethered to thehose handlersbelt, or a watchbuddy should benearby holdingthe cord and

ready to relieve in the event of an emer-gency. Its practically an industry-widepractice to have two hose handlers work-ing together to relieve one another whileworking. Nearly every injury in our indus-try occurs because these three devicesarent working or arent operative. If allthree are working, you wont have injuries.

3. Always ground the truck.Grounding is important for any prod-

uct an operator uses. You might be suck-ing grain dust, and static electricity couldtrigger a dust explosion. Air moversshould never be used on anything beingremoved with a temperature flash point of140 degrees or less. That has beenaccepted as an industry standard.

4. Wet and dry material shouldnever be mixed.

In most cases, an operator does notknow what chemical reaction may occurif wet and dry materials are mixed. In

classroom settings, at one time I usedwater and Alka Seltzer to demonstratewhat could happen when two seeminglysafe products were mixed. I would putwater in a jar fitted with a pressure gaugeand add eight tablets of Alka Seltzer. Oneday it blew the jar apart there was noplace for the pressure to escape and Ihad to discontinue that demonstration.

But the point remains: Who knowswhat might happen in a tank full of wetand dry materials that happen to act likewater and Alka Seltzer? The only excep-tion to this safety rule might be in a situa-tion where acid is to be neutralized with aknown chemical like bicarbonate ofsoda. This is a common activity in thechemical cleaning industry. In that case,the operator knows what he is doing andwhy, and so should not have troubleworking safely.

Being vigilantTodays high-powered vacuum trucks

can give an operator a false sense ofsecurity. They are very forgiving perform-ance-wise, even when not used properly.But in the end, performance relatesdirectly to the operators knowledge andcare. Knowledge of your truck and com-mon safety measures will aid perform-ance and prevent serious accidents.

Phil Stein of Guzzler Manufacturinggives vacuum truck training seminars toaudiences across North America. He presented his Vacuum Truck OperatorsTraining Preview program at the 2002Pumper and Cleaner EnvironmentalExpo International. Truck operators face special safety issues when working in residential or urban

environments.

Tip Top Relief Valvefrom Bandlock.

2002, COLE Publishing Inc.

Reprinted with permission from Pumper, July 2002

COLE Publishing Inc., P.O. Box 220, Three Lakes, WI 54562

800-257-7222 / www.pumper.com