Difference Between Schedule 40 and Schedule 80 Pipe

You may have come across the terms of Schedule 40 Pipe and Schedule 80 Pipe when purchasing PVC Adamjee Pipes. Surprisingly these terms have nothing to do with timing but with the thickness of the pipe. Knowing which type of PVC is right for your situation is essential. That is why, in this guide, we are going to elaborate on the difference between Schedule 40 and 80 pipes.

Schedule PVC Pipes

The pipe schedule specifies the inside diameters and wall thicknesses for pipe nominal sizes. The schedule number has no meaning if the nominal pipe size is unknown, except that a higher schedule number will result in thicker pipe walls if the nominal pipe size remains constant. However, we can calculate the wall thickness and inside and outside diameter dimensions if we know nominal pipe size and schedule number.

According to International Standards Institute, wall pipe thickness varies between Schedule 10, Schedule 40, Schedule 80, and Schedule 160. Among these variations, the most useful polyvinyl pipes are Schedule 40 pipe and Schedule 80 Pipe.

Pipe Scheduling: Schedule 40 & Schedule 80

First, pipeline planning has nothing to do with human notions of time or schedule rather a deterministic measurement model. Scheduling is a design procedure used to determine the total required wall thickness of plumbing materials based on the total pipe size in terms of width, not length.

You can think of a pipeline schedule as a pre-populated data sheet with standardized values from pipe and fittings manuals. Manufacturers looking to produce 2″ Schedule 40 PVC pipe will know what (minimum) thickness of the pipe walls lies under 2″; same for Schedule 40 pipes. Requirements for exact pipe thickness vary depending on the specific piping program planned and the desired total width diameter of the plumbing.

By definition, as the values of a pipeline schedule increase, e.g., Sch. 40 against Sch. 80, the wall thickness also increases. It indicates that Schedule 80 pipe will always have thicker sidewalls than Table 40 pipe when used for specified pipe diameter and material. Between pipe schedules, the pipe wall thickness is the main variable/parameter that changes and corresponds to the change in the inner diameter of the pipe.

Difference Between Schedule 80 & Schedule 40 PVC Pipe

Although the outside diameter of the schedule 80 pipe and Schedule 40 pipe are the same, the 80 pipe has a thicker wall. What else? Let us see thoroughly!

Pressure

Pipes scheduling determines the maximum pressure rating in pounds per square inch (PSI). Pipes and fittings with higher schedules hold immense pressures. Their tolerance to fluid pressure increases is a direct result of the increased material thickness indicated by the piping schedule. For pressurized fluid applications, Schedule 80 is generally the safer and more durable choice. However, the 40 programs can be very suitable if the application pressure range is within the defined parameters of the pipeline.

NPS and Outer, Inner Diameter

Nominal Pipe Diameter (NPS) measurements for Schedule 40 pipe as well as Schedule 80 pipe will be the same for the same pipe diameter. NPS is similar to measuring the outside diameter (OD) of tubes for both types of schedules.

The inside diameter (ID) measurement is different in both Schedule 40 and Schedule 80. The Schedule 80 uses additional materials to increase the thickness of the inner wall. It reduces Schedule 80’s inner diameter of the Schedule 80 for minor restriction in fluid flow through the pipe.

Costs & Weight

Weight and price are two other factors that can affect the PVC Schedule you choose. Because Schedule 80 PVC has thicker walls, it is heavier than Schedule 40 equivalent pipes and fittings. It often makes shipping more expensive and more arduous to handle when installing large pipes and fittings. Schedule 80 PVC is also more high-priced than Schedule 40 because it requires an additional PVC and withstands higher pressures

Colours

The 40 and 80 Schedule palettes often have different colours. Schedule 40 plumbing comes in a traditional natural white colour without any colour additives, while Schedule 80 plumbing comes in a conventional grey. While colours can often indicate and contrast with v 40 and 80 piping, always verify by checking the details printed on the sides of pipes and fittings.

Installation

Installation does not differ between Schedule-40/80 piping made of the same material. The outside diameter will be equal for all pipe schedules with the same NPS. This specification allows pipes with different schedules to be coupled using fittings and assembly methods common to that piping material.

Corresponding Applications and Uses

Due to the greater wall thickness of Schedule 80 plumbing, it is more durable and stronger than its Schedule 40 counterpart is. Plumbing applications with maximum pressure stress, mechanical stress, and chemical interaction require thick piping schedules, like 80 for imperative components.

Dangers

If a higher schedule pipe inspected in the plan or by inspectors, the contractor must never replace the lower schedule pipe for any reason. The use of any building material that does not withstand the stress of regular use or the environment can have severe consequences. Ultimately, the hazards with Schedule 80 are high.

In summary

Schedule 80:

Handle up to 400 PSI
For chemical, industrial, & manufacturing uses
Thinner wall thickness (0.218” on a 2” nominal pipe)
Expensive
In gray colour (mostly)

Schedule 40:

Handle up to 280 PSI
For residential plumbing & irrigation purpose
Thinner wall thickness (0.154” on a 2” nominal pipe)
Affordable
In white colour (mostly)

Takeaway

So what PVC schedule do you need? If you are considering undertaking a home repair or irrigation project, a Schedule 40 PVC Pipe is probably the right path. Even 40 Schedule PVC has impressive pressure resistance and it is more than enough for any home application.

You will also save some money by following the 40 schedules, especially if you plan to use large diameter parts. If your work is industrial or chemical, you will probably want to use Schedule 80. These will likely put more pressure and tension on the material, so thicker walls are required.