Steel pipes are standard everywhere, from industries to houses. Several steel pipes are available, but the most frequently used are SCH 40 and SCH 80. By their initial names, many people consider them similar. However, there are significant differences between SCH 40 and SCH 80.
These differences decide the functionality of these pipes in various applications. If you use these steel pipes without knowing their specifications, you will have unwanted results. So, knowing the difference is key whether you choose for your house or any project. This article will explore the main differences between SCH 40 and 80 pipes. Let’s get started!
Overview of Schedule 40 & 80 Steel Pipe
In the previous articles, I covered SCH 40 vs SCH 40s and SCH 10 vs SCH 40 pipes. But this piece is dedicated to SCH 40 and SCH 80 which are the most common steel pipe types. SCH indicates the schedule which determines the thickness of pipes. In general, millimeters or inches are used to measure the thickness of something.
But using mm or inches is confusing in several regions of the world. The American National Standards Institute (ANSI) eliminated this issue by introducing this unit. The schedule indicates the thickness for 40 and 80 steel pipes. The higher the schedule number, the higher the thickness, and vice versa.
This means SCH 80 steel pipes have more wall thickness than SCH 40 steel pipes. Remember, the wall thickness is also influenced by diameter. The larger the diameter, the higher the thickness. For example, a SCH 40 pipe with a 2-inch diameter is thicker than a SCH 40 pipe with a 1-inch diameter. The same is the case with SCH 80 pipes.
Moreover, variation in schedule number also affects several other factors. For example, an SCH 40 pipe will have a different pressure capacity than a SCH 80 pipe. This variation also makes their usability different for various purposes. For instance, a SCH 40 steel pipe suits the low-pressure system. Conversely, a SCH 80 steel pipe is best suited for heavy-duty applications such as hydraulic systems.
Schedule 40 vs 80 Steel Pipe: Key Differences
As I said above, not all pipes are built the same. Regarding SCH 40 and 80 steel pipes, a slight difference can make a significant impact. So, before making a final decision, it is crucial to understand these differences. Let’s explore the main factors that set SCH 40 and SCH 80 apart.
1- Wall Thickness and Strength
The most vital differences between SCH 40 and SCH 80 pipes are wall thickness and strength. As I said above, the higher the schedule number, the larger the wall thickness. So, it is clear that a SCH 40 steel pipe has less wall thickness. For example, a 1-inch SCH 40 steel pipe has a wall thickness of about 3.56 mm. So, a lower wall thickness directly affects the strength.
A SCH 40 steel pipe is less strong and less durable comparatively. It cannot effectively withstand external physical impacts. On the inverse side, SCH 80 steel pipes have thicker walls. For example, a 1-inch SCH 80 steel pipe has a wall thickness of about 4.55mm. That’s why these pipes also have more strength and durability. They can easily withstand environmental changes.
2- Pressure Capacity
Pressure capacity indicates a material’s ability to withstand internal pressure. Both SCH 40 and SCH 80 steel pipes vary in this term. A SCH 40 stainless steel pipe has less pressure capacity. The reason lies in its lower wall thickness. It cannot withstand the extreme fluid pressure inside. For example, a 1-inch SCH 40 pipe can withstand only 300 psi internal pressure.
Conversely, SCH 80 steel pipes are the clear winner in pressure capacity. As you know, they have higher wall thickness to withstand higher internal pressure. For example, a 1-inch thicker SCH 80 steel pipe can handle 400 psi pressure. Therefore, they are designed for applications where significant pressure capacity is required.
3- Flow Capacity
Flow capacity refers to the maximum volume of fluid that can pass through a pipe at a certain time. This is another factor that sets these two steel pipes apart. Most people mix flow capacity with pressure capacity and consider both the same, but this is the opposite term. For example, SCH 80 pipes have less flow capacity.
The reason is its thicker wall, which allows less fluid to pass in the unit time. On the other hand, SCH 40 steel pipes have a higher flow capacity. As you know, these pipes have thinner walls, which decrease the internal diameter. As a result, it does not hinder the flow of fluid, so a significant volume of fluid can pass in less time.
4- Weight and Handling
Weight is the key distinction between SCH 40 and SCH 80 steel pipes. You should know that weight is directly related to wall thickness. So, a SCH 40 pipe is lighter due to lower wall thickness. For instance, a SCH 40 steel pipe with 2 inches of thickness is lighter than a same-thickness SCH 80 steel pipe. This lightweight SCH 40 pipe makes them easy to handle.
For example, they are easy to install and transport. In contrast, SCH 80 steel pipes have a higher wall thickness. This means they add more materials, which increases their weight. So, these pipes also create difficulty in handling. For instance, they are challenging to install and transport due to their weight.
5- Application Suitability
Due to variations in several factors, both steel pipe types have different applications. The applications vary with thickness, weight, pressure, and flow capacity. As you know, SCH 40 steel pipes have low to medium pressure capacity. So they are used in residential plumbing, irrigation systems, and sewage pipelines.
On the other hand, SCH 80 steel pipes are more durable and have higher pressure capacity. Thus, they are applicable for applications where significant strength is required. They are primarily used in chemical processing plants. Moreover, SCH 80 also transports gas and oil to distant areas. Lastly, the fire suppression system and feed boilers also use these pipes.
6- Cost and Affordability
Another factor that differentiates SCH 40 & 80 pipes is their cost. As you know, SCH 40 pipes require less material for manufacturing. This reduces the cost of raw materials. Moreover, these pipes offer easy handling during manufacturing. Lastly, SCH 40 pipes are lightweight. Therefore, they are easy to transport, which reduces additional costs.
Conversely, SCH 80 steel pipes are thicker and more durable. This means that they are manufactured using more steel. Moreover, a thick material requires more heat treatment for the final shape. So, overall, the manufacturing cost of SCH 80 steel pipes is higher. Moreover, their higher weight also increases the transport cost.
Choosing the Right Pipe For Your Needs
The success of a project depends on minor details, from strength to flow. Are you struggling to decide between schedule 40 and 80 steel pipes? Worry not! The section below will discuss some factors to consider when choosing a steel pipe. They will help you make the right decision about your selection. So, let’s jump right in!
- First, understand the requirements of your project. For example, if you are considering a pipe for your home plumbing system, SCH 40 steel pipe is a good option. However, you should use more robust SCH 80 pipes for an industrial setting.
- As you know, both pipes behave differently in different environmental conditions. So, thick-walled SCH 80 steel pipes suit harsh outdoor installations. Due to their thin walls, such 40 are best suited for moderate indoor conditions.
- Evaluate the pressure capacity of both pipes. If your project demands a higher pressure capacity, SCH 80 is an ideal match. Conversely, due to their thin walls, SCH 40 steel pipes cannot handle higher pressure. So, if you require low-pressure capacity, choose SCH 40 pipes.
- If you prioritize long-term performance, go for a robust pipe option. So, with a thick wall, SCH 80 steel pipes are stronger and ensure durability. Meanwhile, SCH 40 steel pipes are relatively weak. You cannot last for a long time.
- Lastly, remember your budget, as both pipe types vary in this regard. SCH 40 pipes are inexpensive and well-matched for less demanding systems. On the other hand, SCH 80 steel pipes are more expensive due to added strength. So, if you have a handsome budget and want long-term performance, go for SCH 80 pipes.
Frequently Asked Questions
Which is better, SCH 40 or SCH 80?
SCH 80 steel pipes are better than SCH 40 steel pipes. The reason lies in their durability and safety. They can withstand harsh environmental conditions. Due to their higher wall thickness, they offer long-term performance, which saves the replacement cost.
Can you use SCH 40 with SCH 80?
You can use SCH 40 and SCH 80 together with the same outer diameter. However, you should ensure that the pressure and flow capacity difference does not affect your project.
How do you calculate the SCH 40 and 80 pipe weight?
You can calculate the weight of per foot steel pipe using the formula:
Weight = (Outer diameter – Wall thickness) × Wall thickness × Pipe length × Density of steel
Conclusion
SCH 40 and 80 are different types of steel or stainless steel pipes. In this article, I have explored the main differences between both types. For example, SCH 80 is more durable and strong. It has more pressure capacity to withstand the higher internal pressure. But it has less flow capacity. So, it allows for less fluid flow in unit time.
On the inverse side, SCH 40 pies are less durable. They have less pressure capacity, which means that they can not withstand higher internal pressure. However, due to their thin walls, they have higher flow capacity, allowing more fluid to pass in unit time. Lastly, they are less expensive. So, depending on the requirements of your project, you should choose the correct option.