How Does A Vacuum Truck Work?

Vacuum Truck Diagram

This diagram shows how a vacuum pump truck works. Keep in mind that the only thing that should ever flow through a vacuum pump or vacuum blower is air. The pump creates a vacuum in the tank, and the vacuum does all the work. If you have any questions or need help with an existing vacuum truck or a new design, feel free to reach out to us at 888-574-3196. We're standing by to build your next vacuum truck.

1) Tank Can

Center cylinder of the tank body. Rolled sheet of steel or stainless steel usually 1/4" inch thick.

2) Tank Head

End cap of the tank body. At LMT, we use a flange and dish (F&D) process to form our tank heads. Constructed of the same material as the tank can.

3) Discharge Port

Generally 3", 4" or 6" pipe connected to a lever, butterfly, or ball valve.

4) Inlet Port

Generally 2", 3", 4" or 6" pipe connected to a lever, butterfly, or ball valve. The inlet port is typically smaller than the discharge port to assure the passage of any large object.

5) Sight Eyes

Used to view the load level of the tank. Generally 2", 3" or 5". Sight eye bowls are constructed of glass or plastic and are removable for easy cleaning. Large tanks generally have three 5" sight eyes at 1/2, 3/4, and full levels.

6) Vacuum/Pressure Guage

Simple gauge indicating the level of vacuum or pressure in the tank.

7) Manway/Hatch/Portal

Tank access port ranging from 12" to 36" in diameter. Essentially for cleaning. Typically located on the top or rear of tank.

8) Vacuum Relief Valve

Safety feature used to regulate maximum vacuum level in the tank. Reduces risk long term tank fatigue and potential for tank collapse. Also allows air to circulate through tank to cool vacuum pump. Mounted as close to the pump as possible.

9) Pressure Relief Valve

Safety feature used to regulate maximum pressure level in the tank. Reduces risk long term tank fatigue and potential for tank collapse.

10) Primary Shutoff

The first line of defense preventing tank contents from entering the pump, available in a variety of sizes and variations. Rated by CFM to be paired appropriately with vacuum pump.

11) Float Ball

Floats to top of tank when full. Constructed of stainless steel or rubber coated plastic.

12) Ball Seat

Gasket-like ring above the float ball creates a seal when tank reaches capacity.

13) Secondary Shutoff

Second component inline preventing tank contents from entering the pump. Available in a variety of styles & sizes. Rated by CFM to be paired appropriately with vacuum pump.

14) Vacuum Pump or Blower

A vacuum pump or blower is used to create a vacuum and airflow in the tank. A rotary vane pump uses 2 to 8 replaceable sliding vanes to move the air. The vanes require constant lubrication using a reservoir and regulated delivery system. A vacuum blower can achieve much higher CFMs and does not require lubrication.

15) Oil Catch Muffler/Oil Separator

Reduces pump exhaust noise level and separates blow-by pump oil for disposal. Appropriately sized to vacuum pump to prevent oil from blowing out of the exhaust.

16) Tank Rails

Supports the bottom of the tank. Available straight (shown) or tapered/sloped.