304 ss pipe pressure rating

Are you currently sourcing 304 stainless steel pipes but unsure of the maximum pressure they can safely withstand? Could selecting the wrong pressure rating lead to leaks, equipment failure, or even costly downtime? For engineers and purchasing managers-particularly in industries such as chemicals, oil and gas, and food processing,these are critical considerations.

 

What Is the Pressure Rating of 304 Stainless Steel Pipe?

The pressure rating of 304 stainless steel pipe varies significantly based on diameter, schedule (wall thickness), and temperature, typically ranging from roughly 900 psi to over 4000 psi for standard, small-diameter pipes at ambient temperatures. Generally, higher schedule numbers (e.g., Schedule 160) offer higher pressure ratings than lower ones (e.g., Schedule 10).

Below is a reference for ASTM A312 TP304 Seamless Pipe at ambient temperature (72°F / 22°C).

Nominal Pipe Size (NPS)	Outside Diameter (OD)	Schedule (Wall)	Wall Thickness (mm)	Allowable Working Pressure (PSI)
1/2"	21.34 mm	SCH 40	2.77 mm	2,300 PSI
1/2"	21.34 mm	SCH 80	3.73 mm	3,500 PSI
1"	33.40 mm	SCH 40	3.38 mm	2,200 PSI
1"	33.40 mm	SCH 80	4.55 mm	3,100 PSI
2"	60.33 mm	SCH 40	3.91 mm	1,400 PSI
2"	60.33 mm	SCH 80	5.54 mm	2,100 PSI

Tips:These values are for seamless pipes. For welded 304 pipes, you must apply a Longitudinal Joint Efficiency Factor (usually 0.85), which effectively reduces the pressure rating by 15%.

 

304 Stainless Steel pipe Pressure Rating Calculator

The pressure rating of 304 stainless steel tubing is determined based on Barlow's Formula:P = 2St/D
By considering the allowable stress (S), wall thickness (T), and outside diameter (D), the maximum allowable pressure is calculated (i.e., 2ST/D).
For 304/304L stainless steel materials, the typical allowable stress at ambient temperature ranges from approximately 16,700 to 20,000 psi (equivalent to 115 to 138 MPa); however, the actual pressure rating depends significantly on the pipe's Schedule number (i.e., wall thickness) as well as the operating temperature.

Click to Get the Complete 304 Stainless Steel Pressure Chart

 

What is the pressure rating for 304 stainless steel pipes at high temperatures?

As temperature increases, the tensile strength of 304 stainless steel decreases. If your system operates at elevated temperatures.such as 800°F (427°C),its allowable pressure rating will be significantly lower than that at room temperature.
At 200°F: You retain approximately 90% of the rated pressure capacity.
At 1000°F: You retain only about 60% of the rated pressure capacity.
Solution: For high-temperature applications, be sure to consult the temperature derating tables found in the ASME B31.3 standard.

Temperature (°F / °C)	Schedule 40 304 SS Pipe - MWP (psi)	Schedule 80 304 SS Pipe - MWP (psi)	Schedule 160 304 SS Pipe - MWP (psi)
70°F / 20°C (Standard Temperature)	2,200 psi	3,000 psi	4,500 psi
200°F / 93°C	2,100 psi	2,850 psi	4,250 psi
300°F / 149°C	2,000 psi	2,700 psi	4,000 psi
400°F / 204°C	1,800 psi	2,400 psi	3,600 psi
500°F / 260°C	1,700 psi	2,250 psi	3,375 psi
600°F / 316°C	1,600 psi	2,100 psi	3,150 psi
700°F / 371°C	1,400 psi	1,900 psi	2,850 psi
800°F / 427°C	1,200 psi	1,700 psi	2,550 psi
900°F / 482°C	1,000 psi	1,400 psi	2,100 psi
1,000°F / 538°C	850 psi	1,200 psi	1,800 psi

 

What Is The Pressure Rating For 304 Stainless Steel Pipes At Corrosion?

In corrosive environments, the pipe wall will thin over time. If your design requires a 5mm wall to hold 2,000 PSI, but corrosion removes 0.5mm every two years, your pipe will fail prematurely.We provide passivation and pickling treatments to enhance the protective oxide layer, extending the life of the pipe under pressure.

 

304 Stainless Steel Pipe Distributor

Material Certification (MTC): Each pipe is accompanied by a certification certificate detailing its chemical composition and mechanical properties, ensuring full compliance with the ASTM A312 standard.
Hydrostatic Testing: We offer in-house hydrostatic testing services to pressure-test your specified pipes prior to shipment, utilizing test pressures reaching up to 1.5 times the pipe's rated working pressure.
Non-Destructive Testing (NDT): For welded pipes intended for pressure-bearing applications, we provide Eddy Current Testing or Ultrasonic Testing services to ensure that the strength of the weld seam is fully equivalent to that of the base material.

304 Stainless Steel Pipe Specifications

Category	Details
Product Types	Seamless Pipe, Welded Pipe (ERW), Precision Pipe, Polished Pipe
Outer Diameter (OD)	6 mm – 630 mm
Wall Thickness	0.5 mm – 30 mm
Length	6 m standard, or customized (3 m – 12 m / fixed length / random length)
Surface Finish	Pickled, 2B, BA (Bright Annealed), Polished (180#–600#), Mirror Finish
Standards	ASTM A312, ASTM A213, ASTM A269, EN 10216-5, EN 10217-7, JIS G3459
Material Grade	304 / 304L (UNS S30400 / S30403)
Processing Services	Cutting, Bending, Welding, Punching, Custom Fabrication
Tolerance	±2.5% thickness, or as per standard requirements
Inspection	MTC (EN 10204 3.1), PMI Testing, UT/RT, Third-party Inspection (SGS/BV)

 

 

FAQ

Q1: Can 304 stainless steel handle 10,000 PSI?
Answer: Generally, no. Standard NPS sizes in SCH 40/80 cannot safely handle 10,000 PSI. You would need "High-Pressure Tubing" with extremely thick walls and specialized outer diameters, or move to a higher-grade alloy like 316L or Duplex 2205.

 

Q2: Does 304L have a lower pressure rating than 304?
Answer: Yes, slightly. The "L" stands for Low Carbon, which is excellent for welding but results in lower tensile strength compared to standard 304. This difference is usually about 5-10% in allowable stress values.

 

Q3: What is the safety factor for 304 SS piping?
Answer: Most industrial standards (ASME) use a safety factor of 3-to-1 or 4-to-1. If a pipe has a burst pressure of 8,000 PSI, the working pressure should be set at 2,000 PSI.