Schedule 80 Pipe Pressure Rating, Price And Properties Sheets

If you are sourcing pipe for a high-pressure system, a chemical plant, or any application where thin walls are not acceptable, Schedule 80 is one of the first specifications you will encounter. But what exactly does Schedule 80 mean? What pressure can it handle? What does it cost? And how do you know whether it is the right choice for your project?This guide answers all of those questions with real data, comparison tables, and practical guide.

 

Key Takeaways

 

Schedule 80 pipe has a thicker wall than Schedule 40 at the same nominal pipe size (NPS), but the same outer diameter.

 

Higher wall thickness means higher pressure ratings, more weight, smaller inside diameter, and higher cost.

 

Stainless steel Schedule 80 pipe typically handles 1,500–4,000 psi depending on grade and size; carbon steel handles 2,000–6,000+ psi.

 

Schedule 80 is required by most piping codes when pipe will be threaded.

 

Price ranges from approximately $2–$8/ft for PVC, $8–$35/ft for carbon steel, and $25–$120/ft for stainless steel, depending on size and grade.

 

What Does "Schedule 80" Mean?

 

The word "schedule" in pipe term refers to wall thickness. It is part of a standardized classification system developed by ANSI and ASME.

 

The formula behind schedule numbers is:

 

Schedule Number = (P / S) × 1000

 

Where:

 

P = Internal service pressure in psi

S = Allowable material stress in psi

 

In simple terms: the higher the schedule number, the thicker the wall, and the more pressure the pipe can safely contain.

 

Three things stay true across all pipe schedules:

 

The outer diameter (OD) is always the same for a given nominal pipe size, regardless of schedule.

 

The wall thickness increases as the schedule number goes up.

 

The inner diameter (ID) gets smaller as the wall gets thicker.

 

This matters a lot when selecting fittings, calculating flow rates, or comparing two pipes of the same size but different schedules.

 

Schedule 80 Wall Thickness and Dimensions

 

The following table shows the dimensions for Schedule 80 pipe per ASME B36.10M (carbon and alloy steel) and ASME B36.19M (stainless steel).

 

Schedule 80 Pipe Dimensions — Full Size Range

Schedule 80 vs. Schedule 40 — Wall Thickness Comparison

 

The wall thickness advantage of Schedule 80 over Schedule 40 grows with pipe size — at 8-inch NPS, Schedule 80 has 55% more wall material and weighs 52% more per foot.

 

Schedule 80 Pipe Pressure Ratings

 

Pressure rating is the most important performance parameter for any pressurized piping system. The maximum allowable working pressure (MAWP) depends on three factors: wall thickness, pipe diameter, and material allowable stress.

 

The governing formula for hoop stress (thin-wall approximation per ASME B31.3):

 

P = (2 × S × t) / D

 

Where:

 

• P = Internal pressure (psi)

• S = Allowable stress of material at operating temperature (psi)

• t = Wall thickness (inches)

• D = Outside diameter (inches)

 

Carbon Steel Schedule 80 Pipe Pressure Ratings (A106 Grade B, 70°F)

 

 

Note: Values are approximate. Always confirm with your engineer using the applicable code edition (ASME B31.1, B31.3, or B31.9) and current material allowable stresses.

 

Stainless Steel Schedule 80 Pipe Pressure Ratings

 

Stainless steels have lower allowable stress values than carbon steel A106B at room temperature, so their pressure ratings are lower despite having the same wall thickness.

 

 

Source: ASME B31.3 Table A-1, allowable stress values for selected grades at 100°F (38°C). Values decrease at elevated temperatures — see temperature derating section below.

 

Effect of Temperature on Pressure Rating

 

As temperature rises, the allowable stress of the material decreases, and the maximum pressure the pipe can safely hold drops accordingly. This is one of the most commonly overlooked factors in pipe selection.

 

 

At 600°F, A106 Grade B retains only 78% of its room-temperature allowable stress — which directly reduces the pressure rating by the same proportion. For high-temperature service, always recalculate pressure ratings at the actual operating temperature.

 

PVC Schedule 80 Pressure Ratings

 

PVC Schedule 80 is non-metallic and has much lower pressure ratings than steel, but is widely used for chemical drainage, irrigation, and low-pressure process lines.

 

 

PVC pressure ratings drop sharply with temperature. At 140°F (60°C), the rated pressure is only 30% of the room-temperature value. PVC Schedule 80 is not suitable for steam service or high-temperature applications.

 

Schedule 80 Pipe Material Properties

 

The mechanical and physical properties of the pipe material determine how it performs under pressure, temperature, and corrosion.

 

Mechanical Properties — Common Schedule 80 Pipe Materials

 

 

Physical Properties Comparison

 

 

Schedule 80 Pipe Price Guide

 

Pipe prices fluctuate with raw material markets, global supply conditions, and order quantity. The figures below represent typical mill or distributor pricing as of early-to-mid 2025 and should be used for budgeting purposes only. Always request a current quotation for actual procurement.

 

Carbon Steel Schedule 80 Pipe Price (ASTM A106 Grade B, Seamless)

 

 

Stainless Steel Schedule 80 Pipe Price (ASTM A312, Seamless)

 

 

PVC Schedule 80 Pipe Price

 

 

Schedule 80 vs. Schedule 40: Which Should You Choose?

 

This is the most common question when specifying pipe. The answer depends entirely on your application.

 

 

Schedule 80 Pipe: Applicable Standards and Codes

 

Understanding which standards apply ensures you order the right material and receive the right certifications with your delivery.

 

 

Corrosion Resistance of Schedule 80 Pipe by Material

 

The schedule (wall thickness) affects how long a pipe survives in a corrosive environment. A thicker wall means more material is available before the pipe wall thins to below the minimum required thickness — but the base corrosion resistance still depends on the material grade.

 

 

For corrosive environments, the additional wall thickness of Schedule 80 extends service life — but selecting the right material grade is always more important than adding wall thickness.

 

Frequently Asked Questions

 

Q: What is the pressure rating of 2-inch Schedule 80 carbon steel pipe (A106 Grade B)?

 

For ASTM A106 Grade B seamless pipe at 2-inch NPS, the Schedule 80 wall thickness is 0.218 inches, the OD is 2.375 inches, and the allowable stress at room temperature is 15,000 psi. Using the hoop stress formula, the MAWP is approximately 2,752 psi. At 400°F, the allowable stress drops to approximately 14,400 psi, reducing MAWP to about 2,644 psi.

 

Q: What is the pressure rating of 2-inch Schedule 80 stainless steel pipe (316L)?

 

For ASTM A312 TP316L at 2-inch NPS Schedule 80, the allowable stress at 70°F is 16,700 psi per ASME B31.3 Table A-1. The MAWP is approximately 3,063 psi — higher than A106 Grade B at the same size and schedule because 316L has a higher allowable stress value.

 

Q: What is the pressure rating of Schedule 80 PVC pipe?

 

At room temperature (73°F), Schedule 80 PVC pressure ratings range from 850 psi at 1/2-inch NPS down to 280 psi at 6-inch NPS. At 140°F (60°C), these ratings drop to approximately 30% of the room-temperature values. PVC Schedule 80 is not suitable for steam or high-temperature service.

 

Q: Is Schedule 80 pipe always stronger than Schedule 40?

 

Yes — at any given nominal pipe size, Schedule 80 always has a thicker wall than Schedule 40, which means higher pressure ratings, greater resistance to external loads, and more wall material available as corrosion allowance. The OD is identical; only the wall thickness and ID differ.

 

Q: Why is Schedule 80 required for threaded pipe connections?

 

Threading cuts into the pipe wall. For NPT threads on a 1-inch pipe, approximately 0.057 inches of wall is removed. Schedule 40 at 1-inch NPS has a 0.133-inch wall, leaving only 0.076 inches after threading—which many codes consider insufficient. Schedule 80 has a 0.179-inch wall, leaving 0.122 inches — a much more adequate safety margin. Most piping codes (ASME B31.1, B31.3) mandate Schedule 80 minimum for threaded metallic pipes.

 

Q: How much heavier is Schedule 80 compared to Schedule 40?

 

At small sizes 1/2" to 1", Schedule 80 is approximately 25–35% heavier per foot than Schedule 40. At larger sizes 6" to 8", the difference grows to 50–55%. This weight difference matters for structural support design, installation labor costs, and freight costs on large projects.

 

Q: What is the inside diameter (ID) of 4-inch Schedule 80 pipe?

 

The OD of 4-inch NPS pipe is always 4.500 inches, regardless of schedule. For Schedule 80, the wall thickness is 0.337 inches, giving an inside diameter of 4.500 – (2 × 0.337) = 3.826 inches. For comparison, Schedule 40 at the same size has an ID of 4.026 inches — about 0.2 inches larger.

 

Q: Can Schedule 80 stainless steel pipe be used for high-temperature steam service?

 

Yes, with the right grade. For steam service up to 750°F, 321 or 347 stainless steel are preferred over 304/316 to prevent sensitization. The pressure rating must be recalculated at the actual operating temperature using the appropriate code's allowable stress. ASME B31.1 governs power piping, including steam lines.