Traditional forms of excavation, like those involving hydraulics, backhoes and hand tools, are being increasingly replaced by hydrovac methods that offer major pluses in critical capability categories such as accuracy, efficiency and safety. From operator accidents and strikes on utility lines to project delays and site damage, the reasons why more conventional approaches are becoming outdated and less utilized are varied and many. The use of less invasive and more precise equipment is now the preferred option, with powerful hydro excavation trucks facilitating significant transformation in the industry.
Hydro excavation is a technique that leverages high-pressure water to loosen soil and perform digging functions. Once the ground material becomes wet and slurry, the hydrovac truck suctions it into a mounted tank and either stores it for later backfilling purposes or transports it to a designated disposal location. With the technology equipped on hydrovac trucks, excavation projects require less risk, labor, time and environmental impact.
To provide a closer look at the role of hydro excavation equipment for today’s construction and utility projects, we’re exploring the finer details of hydrovac trucks and their typical applications.
Main Components of a Hydrovac Truck
The hydrovac market comprises a variety of truck models, each one featuring different levels of water pressure, suction and capacity. But all of them feature some basic components to perform hydro excavation functions effectively, including the following:
- Water Tank: This component stores the water to be used for both excavating the soil and cleaning the debris tank once disposal is complete.
- Water Pump: This is the part that pressurizes and moves the water from the tank to the soil. Pressurization levels will vary depending on the soil materials and conditions, with most nozzles featuring about 3000 psi and a nozzle flow rate of 6 to 12 GPM.
- Vacuum Pump: This element supplies the suction for moving the wet, muddy soil from the ground site to the debris tank. The pump creates negative pressure through a suction hose, which lifts the debris from the site and transports it through the hose to the tank. Usually, these pumps are either of the liquid ring or rotary vane variety, both of which rely on an eccentrically mounted rotor.
- Boom: This is the part (or hose) used to physically reach the site from the truck’s debris tank. Boom can extend up to 35 feet and rotates 342 degrees for easy reach of the working area.
- Debris Tank: This tank both stores the excavated material and offloads it for backfill or to a disposal site. On most hydrovac trucks, the debris tank is equipped with hydraulic hoists and doors to support dumping functions.
Factors Impacting Choice of Hydrovac Equipment
Choosing which hydrovac trucks are best for specific types of projects and applications comes down to a few important considerations. Here are some of the most defining factors that impact this decision:
- Ground Material & Conditions: One of the most consequential considerations is the type or variety of soil conditions the equipment will be expected to handle, and in some cases, this could be affected by weather. If, for instance, the truck will be needed for cold climates where frozen soil is a challenge, the equipment must include a water heating mechanism. Or, if you’re dealing with sandy material that’s prone to stickiness, the equipment must be able to properly dispose of it from the debris tank.
- Excavation Depth: How deep the equipment will be expected to dig will be another determinant, depending on the types of projects involved. Piling jobs that require depths of many feet, for example, will require a blower that meets those specifications.
- Site Distance: There are some areas where the trucks themselves cannot drive directly onto or near the site. Therefore, it’s necessary to understand how far from the excavation site the truck will be located for various applications. The further the vacuum source is positioned from the actual excavation site, the more power you’ll need from a hydrovac blower.
- Road Access & Legal Compliance: Will the hydrovac truck mainly be used for on-road or off-road applications? Many projects involving pipelines or oil and gas work will require trucks equipped with off-road capabilities. In addition, state laws governing weight restrictions should be factored into the specifications for a hydrovac truck.
- Debris Disposal: The location and environment of the site(s) at which you plan to dump debris will have an impact on the necessary dump height and control a hydrovac truck should accommodate.
Common Hydrovac Applications
Hydro excavation equipment is designed to perform a number of different applications with regard to construction and utility work. The equipment’s ability to dig accurately, powerfully and safely makes it an ideal solution for some of the following jobs:
- Slot trenching, or digging narrow trenches to install buried pipelines, cables or other underground infrastructure. The hydrovac method ensures that ground material is removed only in the necessary areas, whereas more conventional equipment does not afford this level of precision.
- Potholing or daylighting, the process of exposing underground utilities without causing damage to them. Hydro excavation’s lack of mechanical means makes it a much safer option for this application.
- Hole piling, or work related to the drilling and excavation involved in installing piles, poles and other cylindrical structures. These types of excavations require reliable methods for digging with a high level of precision, particularly for small-diameter piles.
- Cold-weather excavation that involves working with soil under freezing temperatures and doing so without causing damage to underground lines.
- Excavation in tight spaces, such as narrow streets or other sites with limited space, where the hydrovac process makes the effort far easier and less dangerous.
Identifying a Top-Notch Fleet
As illustrated here, the highly effective and advantageous process of hydro excavation relies not only on the people doing the work or the approach itself, but quite heavily on the actual trucks and equipment. That’s why Merut Construction prides itself on maintaining a fleet of hydrovac trucks that meet various excavation needs and highlight the importance of doing each job both well and safely.
Our line-up of industry-leading Tornado Global Hydrovacs includes two F4 models (a 2014 Freightliner Vac and a 2015 Western Star Vac) as well as three F4Eco Lite models (a 2019 Kenworth Tornado F4 Vac and two 2019 Peterbilt Tornado F4 Vacs). The engines range in horsepower from 510 to 550, and all are equipped with a Robuschi 145 blower, a Cat 3560 or Pratissoli KT28A water pump, a Hotsey or DynaBlast boiler and debris tanks of 12 to 13 CU YD. These trucks are engineered to be safe, productive and durable, enabling our crew to manage hydro excavation tasks with a high level of performance and a low level of risk.