What Is the Pressure of DI Pipe? [Ultimate Guide]

When choosing a DI pipe, the pressure rating is an important factor to consider. There are different pressure classes for DI pipes, such as class 50, 125, etc. Each shows the maximum working pressure the ductile iron pipe can resist. Different factors, such as wall thickness, pipe diameter, material properties, and joint types, can impact these classes. By comprehending these pressure rates, professionals can make wise decisions based on their needs. Keep reading to learn more about DI pipe pressure ratings and so on.

Understanding the Pressure Ratings of DI Pipes

If you want to use ductile iron pipes for the project, you must understand their pressure rating. According to McWane Ductile, the DI pipe pressure rating can affect its specification, design, installation process, etc. These ratings are offered to meet a variety of professional needs. Therefore, it’s important to understand pressure classes and their influential factors. In this way, you ensure the success of the project, and all needs will be perfectly met.

What Are the Different Pressure Classes of Ductile Iron Pipes?

The pressure rating categorizes ductile iron pipes into different classes. These classes are based on the maximum working pressure for ductile iron pipe. Although there is a wide range of DI pressure classes, five are the most popular ones.

Class 50: It offers a maximum working pressure of 500 psi.
Class 125: It offers a maximum working pressure of 1250 psi.
Class 150: It offers a maximum working pressure of 1500 psi.
Class 250: It offers a maximum working pressure of 2000 psi.

Here is a pipe pressure chart explaining each DI pressure class property.

Specifications	Maximum Working Pressure	Nominal Size Range	Minimum Wall Thickness	Applications
Class 50	500 psi (34.5 bar)	3 to 64 inches	0.18 inches	They are suitable for water distribution systems, sewage force mains, and low-pressure gas lines.
Class 125	1,250 psi (86.2 bar)	4 to 64 inches	0.25 inches	They are suitable for high-pressure water transmission and sewage force mains.
Class 150	1,500 psi (103.5 bar)	4 to 64 inches	0.28 inches	They are suitable for water transmission systems and industrial process piping.
Class 250	2,000 psi (137.9 bar)	4 to 64 inches	0.32 inches	They are suitable for large-scale water transmission systems, fire protection lines, and certain industrial processes.

Each ductile iron class offers unique specifications and features. You should consider them all to ensure optimal performance and efficiency.

What Factors Affect the DI Pipe Pressure Rating?

There is an expansive range of factors influencing the working pressure of ductile iron pipes. Once you understand how these factors change the DI pressure rating, you can make a wise decision. The most important factors are listed below.

Pipe Diameter: One of the most influential factors in DI pressure rate is its diameter. Generally, smaller DI pipes can handle more working pressure than large-diameter ones. That’s because small-diameter pipes can handle deformation under pressure.
Material Properties: DI pipes can be manufactured using different approaches and methods. Therefore, DI pipe specifications can differ, which also affects the pressure rating. For instance, the centrifugal casting process can make ductile iron pipes physically stronger. So, these types of DI pipes have higher pressure ratings due to their specific properties.
Performance Temperature: The area temperature where the ductile iron pipe should work can impact the pressure rating. Higher temperatures can lower this rating and make the DI pipes more vulnerable.
Wall Thickness: Another important factor to consider is the wall thickness. Typically, DI pipes with thicker walls can resist working pressure more efficiently. On the other hand, pipes with thinner walls aren’t that much resistant to pressure. The pressure class of DI pipes usually refers to wall thickness.
Joint Types: The connection type of the pipe system can affect its pressure rating. For example, mechanical joints are usually less resistant to pressure than other connection types.

As explained, knowing such influential factors is a must. It helps you to take good care of the piping system and keep it as efficient as possible.

Working Pressure Vs. Burst Pressure of DI Pipes

Now that you are familiar with the pressure classes of DI pipes, it’s time to learn more about this case. Working and burst pressures are two different concepts that are very important in DI piping systems. Having this knowledge reduces possible risks and prevents any further issues on projects. Keep reading to learn more about this matter.

How Is Working Pressure Rate Different from Burst Pressure?

These two have different definitions. It’s important for professionals to understand this distinction.

Working Pressure: As you can guess, it’s the maximum amount of pressure a ductile iron pipe can handle. The important point is that experts measure this number under normal and standard operating conditions. Moreover, the maximum pressure should be applied continuously during the test. That’s how they measure the working pressure of the DI pipe.
Burst Pressure: It’s a number showing the maximum pressure a DI pipe can resist. The key difference is that the ductile iron pipe falls or ruptures after reaching this pressure rate. That’s why knowing ductile iron pipe burst pressure is crucial for system safety. Otherwise, the integrity and structure of ductile iron pipes get damaged if the burst pressure passes the limit.

How to Keep the Condition Always Safe?

As you understand, there are specific limits for each type of pressure that you shouldn’t exceed. That’s why there are some specific safety margins to consider to keep the situation safe.

The safety factor for DI pipe working pressure should be at least 2.0 to 2.5 times the maximum rate.
Regarding DI pipe working pressure, the safety factor should be at least 3.0 to 5.0 times the maximum rate or more.

You should also consider other factors, such as fluid properties, estimated lifespan, installation requirements, operating temperature, etc., to ensure the safety of your DI piping system.

Testing Methods for DI Pipe Pressure Rating

It’s critical to test the DI pipe’s pressure rate. This gives a realistic idea of what you can achieve with these ductile iron pipes according to their pressure rating. That’s why experts run some tests to maintain the quality and compliance of the DI piping system.

What Are the Most Common Tests for DI Pressure?

There are two prevalent tests to measure the pressure of DI pipes.

Hydrostatic Test: In this test, professionals fill the ductile iron pipe with water to apply the required pressure. The applied pressure is usually higher than the working pressure rate. It helps experts to understand any potential problems, cracks, or leaks through the pipes.
Pneumatic Test: During this test, professionals use compressed air for another gas instead of water to apply the needed pressure. Pneumatic tests are less costly than hydrostatic ones and also offer results more quickly.

Why Is Pressure Testing So Important?

DI pipe pressure testing is very vital since it provides valuable information. There are many reasons to run these tests in any piping system.

It confirms the integrity of ductile iron pipes that handle pressure.
It assesses the quality of DI pipe manufacturing. High-quality products offer a long lifespan and quality of performance. Fortunately, Yasmin Trading is one of the leading suppliers of Ductile Iron Pipes throughout the Middle East and Africa. We offer superior products and care about our customers’ satisfaction.
They maintain industry codes and standards to make sure they fit their intended purpose.

Factors Influencing the Pressure Loss of DI Pipes

One of the most common problems in ductile iron piping systems is pressure loss. It significantly affects energy consumption, efficiency, systems performance, etc. Some factors impact pressure loss in ductile iron pipes. Understanding these factors can help professionals control the situation.

Pipe Diameter

It’s one of the most important properties impacting fluid flow and friction. Pressure loss usually happens for DI pipes with smaller diameters.

Elevation Changes

Once the elevation increases, you can expect pressure loss.

Friction

As explained by Pipe Flow, it’s the most important factor in the pressure loss of DI pipes. The more friction, the more pressure loss, and it negatively affects the flow velocity.

Flow Rate

A flow rate that is too high can lead to pressure loss in DI pipes.

Fittings

Various sorts of fittings, such as elbows, tees, etc, can reduce the speed of fluid flow. That’s how they prevent pressure loss.

Pipe Length

Longer DI pipes usually experience pressure loss more often.

These factors effectively prevent pressure loss, a common problem. When you know how to avoid such conditions, you can optimize your system performance.

Final Thoughts

Considering all vital aspects, you can create an effective DI piping system. From choosing the right pressure class of DI pipe to preventing pressure loss, they are all necessary for your project’s success. Consult our professionals for more information and ask all your questions!