Everything You Need to Know About DB2 Conduit

One of the standout features of DB2 conduit is its lightweight construction. Made from rigid PVC, DB2 conduit is significantly lighter than metal alternatives, making it easier to handle, transport, and install. This not only reduces labor costs but also speeds up the overall installation process.

DB2 conduit offers a highly cost-effective solution for underground electrical installations. Its price point is generally lower than metal conduits, and since it doesn’t require additional treatments like corrosion protection, DB2 conduit reduces both initial material costs and long-term maintenance expenses.

According to the standard, conduit samples must withstand an impact energy of 61 joules at 23°C and 34 joules at -18°C, using the Method A test procedure.

Out of ten specimens tested at each temperature, at least nine must show no visible cracking or splitting, either on the interior or exterior surfaces, when examined with normal or corrected-to-normal vision.

This performance requirement demonstrates the conduit’s ability to endure substantial mechanical stress under both typical and cold-weather conditions without compromising structural integrity.

DB2 conduit is specifically engineered for underground applications, where long-term mechanical load from soil pressure is a critical factor.

According to CSA C22.2 No. 211.0, DB2 conduit must exhibit limited deformation under load. When tested at 23 ± 2°C, the average reduction in diameter under applied load must not exceed 10%, and must recover to within 5% of its original diameter after the load is removed.

Underground environments often expose conduit systems to moisture, chemicals in the soil, and potential contaminants.

DB2 conduit must pass the chemical resistance test defined in CSA B137.0 (Definitions, general requirements, and methods of testing for thermoplastic pressure piping), showing no more than 2% mass change after 7 days of immersion in designated chemical solutions.

Additionally, its tensile strength must remain within 15% of the original value after chemical exposure.

These requirements confirm that DB2 conduit resists degradation, swelling, or loss of strength when in contact with water, salts, or mild acids—ensuring longevity in challenging installations.

DB2 conduit is designed with a careful balance between structural stiffness and manageable flexibility. Per ASTM D2412 (Standard Test Method for Determination of External Loading Characteristics of Plastic Pipe by Parallel-Plate Loading), it must achieve a minimum pipe stiffness of 300 kPa at 5% deflection, ensuring sufficient resistance to deformation from soil or backfill pressure.

At the same time, its thinner wall (compared to Schedule 40 or 80 PVC) allows for easier handling and bending during installation. This balance reduces installation time and labor costs while maintaining the mechanical protection needed for buried electrical systems.

DB2 conduit is engineered to meet essential fire safety requirements, one of its key features is flame retardancy—it does not support combustion and will self-extinguish once the flame source is removed. This property helps limit the spread of fire and contributes to overall system safety.

Manufacturers often incorporate specific additives into the PVC formulation to achieve these flame-retardant characteristics. For example, at Ctube, we carefully formulate our DB2 conduit using high-quality, tested compounds to ensure consistent flame resistance across batches. The result is a conduit that complies with relevant safety standards while remaining lightweight, durable, and easy to install.

To help illustrate its benefits, we’ll first compare DB2 with another widely used PVC conduit: Schedule 40.

By understanding how DB2 stacks up against Schedule 40 PVC, you can better assess which option is best suited for your underground electrical installation needs.

The data in this example are based on Ctube products.

One of the most notable differences between DB2 conduit and Schedule 40 conduit is the weight.

For example, Ctube’s 2-inch Schedule 40 PVC conduit weighs approximately 3.24 kg per 3.05-meter length, while Ctube’s 2-inch DB2 conduit weighs only 1.7 kg for the same length.

Another notable difference between Schedule 40 and DB2 conduit lies in their wall thickness and strength.

For a 2-inch diameter conduit, Schedule 40 PVC has a wall thickness of 3.91 mm, while DB2 PVC has a thinner wall thickness of 2.02 mm.

The thicker wall of Schedule 40 conduit provides greater durability and impact resistance than DB2 conduit.

In addition to the differences in weight, wall thickness, and performance, another key factor to consider is the price.

Since Schedule 40 PVC conduit offers superior physical protection and strength due to its thicker wall, it generally comes with a higher price tag compared to DB2 conduit.

As a result, transportation and labor handling costs also increase.

DB2 conduit provides a more affordable option for underground installations without compromising essential performance. The overall savings in material costs, transportation, and installation make DB2 conduit a highly competitive choice for projects where budget efficiency is a priority.

Unlike metal conduits, which can be cumbersome and require special lifting equipment for handling, DB2 conduit is lightweight enough for installers to work with manually, which can contribute to overall labor cost savings.

DB2 is much lighter than RMC, making it easier to handle and faster to install without special lifting tools.

DB2 conduit is made of non-metallic rigid PVC, making it naturally corrosion-resistant. This is a major advantage over metal conduits, such as RMC, which can rust and corrode over time, especially when exposed to moisture or harsh weather conditions.

Another significant difference is electrical insulation. DB2 conduit is made from PVC, a non-conductive material, which provides built-in electrical insulation. This eliminates the need for separate grounding or bonding steps, which are essential when working with metal conduits like RMC.

From a cost perspective, DB2 conduit offers a clear advantage over metal conduits like RMC. DB2 is more affordable in both material cost and installation, as its lightweight design reduces the need for specialized labor or equipment.

Metal conduits, on the other hand, tend to have higher material costs and require more complex installation.

It’s important to acknowledge that while DB2 conduit is lighter and more cost-effective, metal conduits may be the better choice in environments where higher strength and durability are required.