Ohio CDL Tanker Test flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Tank leak discovered in pre-trip

A leaking, cracked, or damaged tank or manhole cover puts the vehicle out of service. Do not move it until repaired or the cargo is safely unloaded and the defect corrected.

Stop valve requirement

Cargo tanks must have an internal or external stop valve at the discharge outlet that closes automatically when released, or is protected against damage in a rollover under 49 CFR 178.345-11.

Pressure relief device check

Vents and pressure/vacuum relief valves must be unobstructed and correct for the cargo. Residue or ice blocking a vent can rupture the tank during loading or heat expansion.

Placard verification

Placards must match the material on the shipping paper and be legible, upright, and displayed as required. A mismatch is a violation and misinforms emergency responders.

Bonding and grounding order

For flammable liquids, connect the ground connection first and break it last. Keep bonding and grounding attached from before hatch opening until transfer and venting are finished.

Baffle inspection

Check baffles and bulkheads for cracks, corrosion, and loose fasteners. A damaged divider lets liquid slam end to end, producing violent surge that can overpower braking and steering.

Internal valve test

Before loading, confirm the emergency shutoff and internal valve close fully. A valve that will not seat drains product into the line when the pump stops.

Tank top product check

After loading, inspect the tank top and frame for spilled product. Pooled liquid is a fire and slip hazard and indicates a leaking hatch, gasket, or fitting.

Rollover threshold of tankers

Tank vehicles have a high center of gravity and a lower rollover threshold than dry vans. Posted curve and ramp speeds are maximums, not targets to match.

Curve force formula

Sideways force in a curve equals mass times speed squared divided by radius. Doubling speed quadruples the outward force, so curve speed is the critical control.

Braking in a curve

Avoid hard braking in a curve. Weight transfers forward, unloading the rear and loading the front, which can combine with surge to cause a rollover or loss of control.

Downgrade gear selection

Select a gear low enough that engine braking and a retarder hold the descent. Use service brakes only to trim speed, never to control a long downgrade continuously.

Following distance for tankers

Allow extra following distance. A loaded tanker needs more stopping distance than a dry van, and a sudden stop ahead leaves no time to manage liquid surge.

Crosswind effect on tankers

The large smooth side area of a tank makes it more sensitive to crosswinds than a dry van. Reduce speed and expect a push on bridges and open stretches.

Partial load stability

A partly loaded tank can be less stable than a full one because liquid moves and shifts the center of gravity. Full or empty tanks have less free-surface movement.

Smooth bore versus baffled

A smooth-bore tank allows the strongest front-to-back surge. Baffles reduce but do not eliminate surge, so smooth braking and reduced curve speed are still required.

Baffle definition

A baffle is a perforated divider inside a tank that slows front-to-back liquid flow while letting product pass. It reduces surge force but does not make the load rigid.

Bulkhead definition

A bulkhead is a solid divider that separates tank compartments and can carry structural loads. It stops flow between compartments rather than merely slowing it.

Forward surge on braking

Hard braking sends liquid forward against the front of the tank, adding force that can push the tractor and cause loss of steering control or a jackknife.

Side surge in turns

In a partly loaded tank, liquid shifts sideways in a turn and loads the outside tires. This raises rollover risk above that of a rigid load at the same weight.

Surge force factors

Surge force grows with the mass and speed of moving liquid. A partly loaded large tank can generate more surge force than a smaller tank at the same fill level.

Damaged baffle consequence

A cracked or loose baffle or bulkhead lets liquid slam from one end of the tank to the other, producing violent surge that can overpower brakes and steering.

Compartment loading rule

Each compartment of a multi-product tank must be loaded within its own capacity. Crossovers and valves between compartments stay closed unless transfer between them is intended.

Surge and stopping distance

Forward surge adds to the vehicle's momentum during braking, so a partly loaded tanker can need more stopping distance than its weight alone suggests.

Outage or ullage

Outage is the empty expansion space left in a tank. Tanks are not filled to the brim; the required space lets liquid expand with heat without overflowing.

Loading area setup

Set the parking brake, chock wheels where required, and shut off the engine unless it powers the pump. Never leave a transfer unattended.

Opening hatches safely

Open hatches and vents slowly and stand upwind. A tank may hold pressure or vacuum, and a sudden release can spray vapor or liquid on the person opening it.

Unloading valve alignment

Before unloading, confirm the receiving tank has room and lines and valves are correctly aligned. A misaligned valve can overfill a tank or release product to the ground.

Post-unloading steps

Drain hoses and lines, close and secure all valves and hatches, and check for product left in the hose or on the tank top before moving the vehicle.

Incompatible residue hazard

A tank that carried another product must be cleaned and purged as required. Residual cargo that reacts with the new load can cause a violent reaction or contaminate the product.

Special cargo handling

Heated cargoes need temperature checks, food-grade cargoes need clean dedicated equipment, and corrosive or toxic cargoes require the specified PPE and respiratory protection.

Shipping paper match

Before loading, confirm the cargo matches the shipping paper, that the tank and its previous cargo are compatible, and that the required placards are on hand.