close all other valves.
8. Ensure the cyclone and air filter are clean.
9. If unloading from rail car, ensure the manhole of the rail car is open.
10. Close clean out valve.

Loading Sequence
1. Start the blower and after allowing it to warm up, adjust the throttle
to maintain the recommended blower rpm.
2. Open the outlet nozzle of the storage container or adjust to hose
probe to attain 8-10” HG on the tank.
3. Smooth product flow to discourage slugging by adjusting bleed air
valve on rail car adapter.
4. In case of emergency or desire to shutdown loading sequence, open
blow-down valve and shut off blower.
5. When the tank is loaded, close the nozzle or remove the probe to
clear the fill line.
6. Open the vacuum dump valve.
7. Shut of the blower and open the blow-down valve.
8. Close the top valve between the tank the cyclone filter.

DANGER
Relieve Vacuum and/or Pressure Before Removing Piping Cap.

Vacuum/Filter Maintenance
See Page 49.
32

SAFETY CHECK
A vehicle safety check should be performed daily prior to operation. See
Preventive Maintenance Section.

START-UP
DANGER
NEVER open manhole unless tank is completely depressurized. Even a
slight amount of residual pressure will cause manhole to fly open when
unlatched.

When units are parked, especially over night, moisture can form inside
the tank and piping. To clear out most of the moisture, remove dust cap
on discharge line, start compressor or blower and pressurize unit. Then
open each of the hopper discharge valves to blow out the unit. This
procedure will help prevent the discharge valves and aerators from
becoming clogged.

CAUTION
Blow-down valve should be OPEN at all times except when unloading.
This will help relieve pressure buildup due to changes in ambient
temperature, friction, product expansion, etc.

LOADING
The type of cargo being hauled and the loading situation will determine
the best method of loading. Heavier materials such as sand and sugar
can normally be loaded through the center manhole and allowed to
overflow into the adjoining hoppers. Light and bulky products such as
flour or plastic pellets should be loaded through the individual manholes
for better distribution. The pneumatic loading line, on units so equipped,
offers an alternate loading method when loading from silo or rail car.

TOP LOADING
1. Close all valves except the blow-down before loading and while in

transit.
2. Position trailer properly for most efficient loading.
3. Ensure all manholes are closed properly after loading.
33

Vacuum Loading a Vacuum Pneumatic Trailer
From Standard Railcar or Silo
1. Position trailer so the hoses will have the least amount of bends for
most efficient loading.
2. Close the blow-down valve and top air valve.
3. Connect the product transfer hose to the rail car or silos product
discharge line and the tanks pneumatic loading line.
4. Open the valve between tank and the vacuum filter.
5. Close the vacuum dump valve on the vacuum suction line.
6. Open manhole of the rail car or vent line of silo to prevent rail car
from collapsing.
7. Start blower to desired RPM.
8. Open opposite side discharge on rail car or vent on silo.
9. Open product valve on rail car or silo, allowing product to flow to
trailer.
10. Shut down blower after trailer is loaded.
11. Open vacuum dump valve, gauge will return to 0.
12. Disconnect piping and lines.
13. Close the top air valve and open the blow-down valve.

NOTICE
Never load/unload payload into a storage facility of unknown contents
or capacity. Check to ensure that the storage facility will accept the
total payload.

WARNING
If vacuum relief valve does not open at pressure specified on valve, shut
off compressor or blower and correct the cause of the inoperative relief
valve. See Page 43 for testing Relief Valve.

34

Vacuum Loading From Pressure Differential Rail Car
A pressure differential car allows for the most efficient loading. A “PD” car is
pressurized by a blower which creates a push-pull loading process when loaded
with a vacuum pneumatic trailer. This this greatly minimizes the load time.

1. Position trailer for most efficient loading.
2. Close the blow-down valve and top air valve.
3. Connect the air supply line from the blower to the rail cars aeration
supply line.
4. Connect the product transfer hose to the rail cars product supply line
and the tanks pneumatic loading line.
WARNING
The Vacuum relief valve MUST be bench tested periodically to ensure it
opens at vacuum pressure specified on valve, to ensure safe vacuum
operation. See Page 43 for testing Relief Valve.

5.

Open the valve between tank and the vacuum filter.

6.

Close the vacuum dump valve on the vacuum suction line.

7.

Open manhole of the rail car to prevent rail car from collapsing.

8.

Open the rail cars aeration valve.

9.

Start blower to desired RPM.

10. Close pressure supply valve on rail car, directing all air to aeration
line.
11. When the tanks vacuum gauge reaches 10” HG, crack pressure
supply valve on the rail car directing air into the tank.
12. Open product valve on rail car, allowing product to flow to trailer.
13. When trailer is full, close all product valves and open pressure
supply valve on rail car 100%.
14. Shut down blower.
15. Open vacuum dump valve, gauge will return to 0.
16. Disconnect piping and lines.
17. Close the top air valve and open the blow-down valve.

35

UNLOADING
1. Position trailer for optimum unloading.
2. Remove cap from vacuum suction line, rear of trailer.
3. Close valve between tank and filter.

4. Retrieve discharge hose and connect it to the discharge line. Attach
opposite end of hose to adapter on storage facility fill line.
5. Open the pressure control valve.
6. Engage blower or compressor.
7. Open all aeration valves and close pressure control valve and blowdown valve. Pressurize unit. If cargo does not require aeration,
open the Top Air Supply Valve to pressurize the unit.

DANGER
When unloading, the discharge hose must be secured at both ends prior
to pressurizing unit. A loose hose will bull whip potentially
causing injury.

8. When unit has reached operating pressure open the proportioning
valve ½ to ¾ of full open.
9. SLOWLY open discharge valve on rear hopper.
10. Adjust the pressure control valve to maintain maximum operating
pressure and slight movement of discharge hose.
11. Close the front and center individual hopper aeration control valves,
on units so equipped.
12. When tank pressure begins to drop rapidly, close rear discharge
valve.
13. Open aeration valve on center hopper.
14. SLOWLY open the discharge valve on center hopper.
15. Close the aeration valve on rear hopper.

36

16. Readjust pressure control valve if necessary.
17. When tank pressure begins to drop rapidly, close center discharge
valve.
NOTICE
When pressurizing unit, look for air leaks. If any are found, shut down
immediately and repair the leak.

18. Open aeration valve on front hopper.
19. SLOWLY open front hopper discharge valve.
20. Close aeration valve on center hopper.

DANGER
Do not exceed working pressure. If pressure rises above limits, shut
down immediately and investigate.

21. When tank pressure begins to drop rapidly, close front discharge
valve.
22. Purge unit by opening all aeration valves and opening and closing
discharge valves rear to front.

CAUTION
Before opening blow-down line, make sure no one is in line of air
stream.

23. Open blow-down line to return the unit to atmospheric pressure.

DANGER
Always relieve pressure in discharge hose before disconnecting it.

24. Disengage blower or compressor.
25. Disconnect and stow discharge hose.
26. Close all valves except the blow-down valve.
37

NOTICE
Variations or deviations to the unloading procedure may be necessary
due to the type of product being unloaded or the nature of the
unloading site. Operating more than one hopper at a time is common
with extremely large capacity blowers or a combination of compressor
and blower only. A second and third hopper can be activated to
maintain desirable product to air mixture.

OPERATING TIPS
MINIMIZING UNLOADING TIME
The Heil Vacuum Pneumatic Trailer is designed with one of the fastest
vacuum discharges in the industry. Unloading time will depend,
however, on variables such as type of product being unloaded,
unloading site, condition of equipment, etc. The following points should
be considered.
NOTE: The most efficient unloading is when your tank and line pressures are equal.
1. Vertical positioning of discharge hose results in smoother product
flow. Product tends to “settle” in portions of hose which runs
horizontally (see Figure 6). This accumulation of product will restrict
product flow, will increase unloading time, and may eventually clog
the line.

Figure 6. Product Flow and Build Up

38

Comparing product flow through a hose in the vertical portion of hose
(Figure 7). It can readily be seen that vertical positioning of hose results
in smoother product flow.

Figure 7. Vertical
Product Flow

NOTICE
If discharge hose must be run horizontally for any considerable
distance, elevate the hose at intervals to create slight “humps” in the
hose. This will help keep the product flowing freely.

39

MINIMIZING UNLOADING TIME (CON’T.)
2. The relative density (product to air ratio) decreases as the elevation
increases. The higher the storage facility, the longer it will take to
unload. Figure 8, illustrates the relative density at various
elevations. Note that as the product head decreases, the air velocity
will increase and air pressure will decrease.

Figure 8. Relative Density at Various Elevations

3. Heavy, fine materials such as sand or sugar require considerably
more unloading time. Light, bulky products offer more resistance
and are more easily carried by the air stream. Use the pressure
control valve and the product discharge valve to maintain the
optimum product-to air ratio for the type of product being unloaded.

40

Landing Gear Operating Instructions
WARNING: Before attempting to operate the landing gear,
you must read and understand the following procedures.
1. Perform all procedures in lighted area clear of obstacles and other
personnel.
2. Always grip the crank handle securely with both hands.
3. Maintain proper footing at all times.
4. Never attempt to shift the landing gear while under load.
5. Lifting and lowering of the trailer must always be done in LOW
GEAR.
6. DO NOT ATTEMPT TO LIFT OR LOWER TRAILER WITH LANDING GEAR
IN HIGH GEAR, AS SERIOUS PERSONAL INJURY COULD OCCUR.
7. Always secure the crank handle when not in use.

TRAILER
RETRACT
LOW
HIGH

EXTEND
Figure 9. Landing Gear

> Push crank handle in for high gear.
> Pull crank handle out for low gear.
> Turn crank: Counterclockwise to Retract, Clockwise to Extend.
41

PREVENTIVE MAINTENANCE
INTRODUCTION
Lubrication and service performed at regular intervals will keep the DRY BULK
TRANSPORT in top operating condition for the longest period of time. The
importance of regular inspection cannot be over-emphasized. Making necessary
adjustments, tightening nuts and bolts, checking air lines, lights and wiring
connections will help prevent serious trouble and delays on the road.
The driver should be the first line of defense in Preventive Maintenance. A
conscientious and alert operator will promptly report all need for adjustment or
repair. A vehicle safety check should be performed daily prior to operation.

LUBRICANTS
It is not the policy of the Heil Trailer International, Co. to guarantee lubricant
performance. The responsibility for the quality of any lubricant rests solely with
the distributor or manufacturer of the lubricant.

DELIVERY INSPECTION
All units are thoroughly tested and inspected at the factory. As an added precaution, the following items should be double checked upon delivery.
Axles……………………………………………………………………….….. Check king pin alignment
Wheels…………………………………………………………………………....Check wheel lug torque
Brakes……………………………………………..Check for proper operation and adjustment
Lights and Wiring…………………………………………….Check lights for proper operation
Air Spring Bolts………………………………………………………….…..Check for proper torque
Shock Absorber Bolts………………………...………………………….Check for proper torque
Suspension Pivot Connection Bolts…………………………….…Check for proper torque
Piping……………………………………………………………………………………….....Check for leaks
Manhole Cover………………………..Check clamping device for proper cover closure
Landing Leg Support Bolts…….……………………………...…….Check for proper torque
Front and Rear Structure Bolts………………………………….…Check for proper torque

42

PREVENTIVE MAINTENANCE SCHEDULE
DAILY
Anti-Lock Brake System…………………………………Check for proper operation
Lights and Wiring…………………………….Check all lights for proper operation
All Bolts………………………………………………………….Visually check for tightness
Air Reservoirs…………………………………………….Drain at the end of each shift
Tires…………………………………………………Check for proper inflation and inflate
WEEKLY
Wheel Seals………………………………………….Check for oil leakage and oil level
Wheel Lugs……………………………………………………….…Check for proper torque
Wiring………………………………………………………….………....Check all connections
Suspension Bolts..…………………………………………….…Check for proper torque
Piping………………………………………………………….…Check for leaks and damage
Manhole……………………………………….........Check clamping device for proper
cover closure and check gasket for damage
Front and Rear Structure Bolts……………………………Check for proper torque
MONTHLY
Manhole………………………………………………………Clean manhole and oil clamps
General Inspection………………………………………..............Perform inspection
Supports……………………Lubricate; check mounting bolts for proper torque
Axle Camshafts………………………………………………Lubricate all grease fittings
90 DAYS
Relief Valves………………………………….Remove and inspect relief valve for
clogs of hardened material. Bench test relief valve to ensure proper
operation.

43

PREVENTIVE MAINTENACNE SCHEDULE
EVERY 5000 MILES

King Pin Alignment…………………………………………Check for proper alignment.
Brakes……………………………………………………………..…….………Adjust as needed.
Wiring............................................Check for chafed or broken wires,
ground wire connections, loose wire retaining clips and dielectric grease.
Upper 5th Wheel……………………….............………………..………………...Lubricate.
Suspension…………………………………………………..Check for proper bolt torque.
Piping……………………………….Check all piping supports, tighten if necessary.
Aeration…………………………Check all aeration tee bolts - hand tighten only.

EVERY 10,000 TO 25,000 MILES
Wheel Bearings………………Verify proper end play and adjust as necessary.
Brake…………………….Inspect linings, free-up brake shoes and anchor pins.
EVERY TWO YEARS
Aeration…………….…………………………….Inspect and replace aeration
components as necessary. At a minimum, trailers in abrasive product
service should be inspected every six months.

44

Lubrication and Service Chart
X

Drain any water from air reservoirs

X

Check manhole clamps, cover closures and gaskets

X

Clean manhole and lubricate its clamps
X

Check the operation of all lights

X

Check all wiring connections

X

Check for broken or chafed wires
X

Check brake operation

X

Adjust brakes (Pg. 50)
Inspect slack adjusters, brake linings and brake chambers

X

Free up brake shoes and anchor pins (Pg. 50)

X
X

Check condition of walkways and toe rails (Pg. 18)

X

Check suspension bolt torque (Pg. 71)
Check tires for damage and wear (Pg. 61)

X
X

Check axle alignment to king pin (Pg. 63)
Check lubricant level and oil seals on the axles (Pg. 58)

X

Check ladder bolt tightness

X

Check the operation of pressure relief device (Pg. 23 & 43)

X

Inspect aeration system (Pg. 47)

X
X

Lubricate grease fittings on axle camshafts

X

Check wheel bearings (Pg. 58)

X

Check lug nut torque (Pg. 62)
Check piping supports and mounting fastener tightness

X

Check front and rear structure fastener tightness

X

Check all valves, piping and manholes for leakage

X
X

Check landing gear mounting fastener tightness
X

Check upper coupler fastener torque

X

Check king pin wear
Lubricate upper coupler plate and king pin

X

Visually check tightness of all fasteners

X
X

Check all supports and braces

Annually

5,000 Miles

Monthly

Weekly

45

Daily

Tank trailer should be inspected periodically to ensure it meets D.O.T.
requirements.
Refer to the D.O.T. Transportation of Hazardous Materials Handbook
(paragraph 177.824) if hazardous materials at to be hauled.

10K-25K Miles

Notice

LUBRICATION & SERVICE
1. Manhole Cover-(Weekly)-check clamping device for proper cover clo-