Nuclear Power Market

Tubing and Engineered Shapes for Nuclear Power

Nuclear power generation places extraordinary demands on materials, requiring proven performance under sustained exposure to radiation, extreme heat, high pressure, and corrosive media. Plymouth^® partners with nuclear facilities and emerging small modular reactor (SMR) designs with precision-engineered tubing and cold drawn shapes that safeguard critical plant assets. These products provide plant designers and operators with trusted solutions for safety-related systems, instrumentation lines, and balance-of-plant applications.

Nuclear Power Applications:

SMR instrumentation & control lines
Steam generator and heat exchanger components
Control rod drive mechanisms
Coolant and safety injection systems
Fuel assembly components
Valve and fitting components
Control rod mechanisms
Boiler and condenser tubing

Tubing and Engineered Shapes for Nuclear Power

Nuclear Power Applications:

SMR instrumentation & control lines
Steam generator and heat exchanger components
Control rod drive mechanisms
Coolant and safety injection systems
Fuel assembly components
Valve and fitting components
Control rod mechanisms
Boiler and condenser tubing

Plymouth^® Nuclear Power Products

Our welded and seamless steel tubing is widely specified for nuclear instrumentation and heat exchanger service, delivering resistance to thermal cycling, pressure fluctuations, and corrosion while meeting ASME Section III – Class 1, 2, and 3 requirements. In addition to our tubing, Plymouth^® cold drawn shapes provide durable, dimensionally consistent solutions for nuclear plant equipment to support reliable operation across the full lifecycle of nuclear power assets.

Cold Drawn Shapes

The robust performance and durability of Plymouth^® cold drawn shapes helps plant equipment perform under exposure to radiation, pressure, corrosive materials, and extreme heat to safeguard the health of nuclear plant assets.

Cold Drawn Shape Specifications

Material Specifications
Carbon & Alloys	US Grades in Series 1000, 4000, 6000, 8000, 9000
Stainless Steel in Complex Geometries	Series 300 & 400 Stainless Steel
PH Grades in Rounds, Hexes or Octagons	17-4, 17-7, 15-5, 13-8
Exotic Alloys	Monel 400, Inconel, Hastelloy, etc.

Shape Specifications
Solid, Round	0.2500” – 3.750”
OD Hexagon and Octagons, across flats	0.3125” – 3.625”
Rectangles and Squares	0.625” per side min, 5.000” max
Unique Shapes	Greater than 0.625”
Profile must fit within 6.500” Diameter Circle

Dimensional Specifications
Dimensional Tolerance, Standard*	+/- 0.005”
Fillet and Radii Tolerance, Standard*	0.015” in Carbon, 0.360” in Stainless
Ratio of Height vs. Width	1 : 1.16 (Max.)
Cross-Sectional Area	0.125 sq. in. (Min.)

*Tighter Tolerances may be available

Seamless Stainless Steel Tubing

Our seamless stainless tubing delivers high resistance to extreme heat, pressure, radiation, and corrosion, as well as adherence to ASME Section III – Class 1, 2, and 3 standards. These specifications provide plant operators with a trusted solution for use in small, modular nuclear reactors, nuclear instrumentation, and nuclear facility heat exchangers.

Seamless Stainless Steel Pressure Tubing

ASTM A/B and ASME SA/SB Specifications	Grades	OD Range	Wall Range	Maximum Length
-213 Seamless Austenitic Alloy Steel Boiler, Superheater and Heat Exchanger Tubing	04/L, 316/L, 317/L, 347, others	0.250” – 1.000” 6.35mm – 25.4mm	0.016” – 0.100” 0.4064mm – 2.54mm	130’ 39.63m
-269 Seamless Austenitic Stainless Steel General Service Tubing	304/L, 316/L, 317/L, 347	0.125” – 1.500” 3.175mm – 38.1mm	0.016” – 0.120” 0.4064mm – 3.048mm	48’ – 130’ 14.63m – 39.63m
-270 Seamless Austenitic Stainless Steel Tubing	304/L, 316/L, AL-6XN^®	0.125” – 1.250” 3.175mm – 38.1mm	0.016” – 0.120” 0.4064mm – 3.048mm	48’ – 130’ 14.63m – 39.63m
-632 Seamless Austenitic Stainless Steel Tubing for General Service	304/L/N, 316/L/N, 321, 347	0.125” – 1.500” 3.175mm – 12.7mm	0.016” – 0.065” 0.4064mm – 1.651mm	130’ 39.63m

Seamless Stainless Steel Commercial Instrumentation Tubing

ASTM A/B and ASME SA/SB Specifications	Grades	OD Range	Wall Range	Maximum Length
-213 Seamless Austenitic Alloy Steel Boiler, Superheater and Heat Exchanger Tubing	304/L, 316/L	0.125” – 1.500” 3.175mm – 38.1mm	0.016” – 0.120” 0.4064mm – 3.048mm	48’ – 130’ 14.63m – 39.63m
-269 Seamless Austenitic Stainless Steel General Service Tubing	304/L, 316/L	0.125” – 1.00” 3.175mm – 25.4mm	0.016” – 0.120” 0.4064mm – 3.048mm	48’ – 130’ 14.63m – 39.63m

Mechanical Properties

Tensile Strength	515 MPa minimum / 75,000 psi minimum
Yield Strength	205 MPa minimum / 30,000 psi minimum
Total Elongation Under Load	30.000%
Hardness	22 Maximum HRC

Alloys

Austenitic: 304/L/N, 316/L/N, 317/L, 321, 347
Duplex/Lean Duplex: 2101, 2205, 2507
Nickel Alloy: 600, 625, 800, 825

Seamless Nickel Alloy Tubing

Heat transfer and balance-of-plant heat exchangers in nuclear power facilities require the corrosion resistance of seamless nickel tubing for optimal performance in sustained high temperatures and pressures.

Nickel Alloy Pressure Tubing

ASTM A/B and ASME SA/SB Specifications	Grades	OD Range	Wall Range	Maximum Length
-213 Seamless Austenitic Alloy Steel Boiler, Superheater and Heat Exchanger Tubing	04/L, 316/L, 317/L, 347, others	0.250” – 1.000” 6.35mm – 25.4mm	0.016” – 0.100” 0.4064mm – 2.54mm	130’ 39.63m
-269 Seamless Austenitic Stainless Steel General Service Tubing	304/L, 316/L, 317/L, 347	0.125” – 1.500” 3.175mm – 38.1mm	0.016” – 0.120” 0.4064mm – 3.048mm	48’ – 130’ 14.63m – 39.63m
Seamless Nickel and Alloy Condenser and Heat Exchanger Tubing	400, 600, 625, 800, 825	0.125” – 1.500” 3.175mm – 38.1mm	0.016” – 0.120” 0.4064mm – 3.048mm	130’ 39.63m

Nickel Alloy Commercial Instrumentation Tubing

ASTM A/B and ASME SA/SB Specifications	Grades	OD Range	Wall Range	Maximum Length
-213 Seamless Nickel and Alloy Condenser and Heat Exchanger Tubing	400, 600, 625, 800, 825	0.125” – 1.500” 3.175mm – 38.1mm	0.016” – 0.120” 0.4064mm – 3.048mm	130’ 39.63m

Welded Nickel Alloy Tubing

Welded nickel tubing is often used in nuclear plant heat exchangers due to its higher corrosion resistance in comparison to stainless steel. These properties optimize the performance of nuclear power facilities through efficient heat exchange in harsh operating environments.

Welded Nickel Alloy Pressure Tubing Specifications

ASTM A/B and ASME SA/SB Specifications	Grades	OD Range	Wall Range	Maximum Length
-249 Welded Austenitic Tubing Boiler, Superheater and Heat Exchanger Tubing	304/L, 316/L, 317/L, 347, others Also available in H and N grades.	0.125” – 4.000” 3.175mm – 101.6mm	0.016” – 0.218” 0.4064mm – 5.54mm	48’ – 130’ 14.63m – 39.63m

ASTM A/B and ASME SA/SB Specifications

Grades

OD Range

Wall Range

Maximum Length

-249 Welded Austenitic Tubing Boiler, Superheater and Heat Exchanger Tubing

304/L, 316/L, 317/L, 347, others

Also available in H and N grades.

0.125” – 4.000” 3.175mm – 101.6mm

0.016” – 0.218” 0.4064mm – 5.54mm

48’ – 130’
14.63m – 39.63m

Welded Stainless Steel Tubing

Our welded steel tubing adheres to ASME Section III – Class 1, 2, and 3 standards to provide the quality of Plymouth^® tubing in a value-optimized alternative to seamless tubing for boiler, condenser, and nuclear instrumentation tubing.

Welded Stainless Steel Pressure Tubing

ASTM A/B and ASME SA/SB Specifications	Grades	OD Range	Wall Range	Maximum Length
-269 Welded Austenitic Stainless Steel General Service Tubing	304/L, 316/L, 317/L, 347	0.125” – 4.000” 3.175mm – 101.6mm	0.016” – 0.218” 0.4064mm – 5.54mm	48’ – 130’ 14.63m – 39.63m
-270 Welded Austenitic Stainless Steel Tubing	304/L, 316/L, AL-6XN^®	0.500” – 4.000” 3.175mm – 101.6mm	0.065” – 0.131” 1.651mm – 3.3274mm	48’ – 130’ 14.63m – 39.63m
-632 Seamless Austenitic Stainless Steel Tubing for General Service	304/L/N, 316/L/N, 321, 347	0.125” – 1.500” 3.175mm – 12.7mm	0.016” – 0.065” 0.4064mm – 1.651mm	130’ 39.63m
-676 UNS N08367	AL-6XN^®	0.250” – 4.000” 6.35mm – 101.6mm	0.020” – 0.120” 0.508mm – 3.048mm	48’ – 130’ 14.63m – 39.63m

Welded Stainless Steel Nuclear Instrumentation Tubing

ASTM A/B and ASME SA/SB Specifications	Grades	OD Range	Wall Range	Maximum Length
-213 ASME Section III – Class 1, 2, & 3	304/L, 316/L	0.125” – 1.500” 3.175mm – 38.1mm	0.016” – 0.120” 0.4064mm – 3.048mm	130’ 42.67m

Mechanical Properties

Tensile Strength	515 MPa minimum / 75,000 psi minimum
Yield Strength	205 MPa minimum / 30,000 psi minimum
Total Elongation Under Load	30.000%
Hardness	22 Maximum HRC

Alloys

Austenitic: 304/L/N, 316/L/N, 317/L, 321, 347
Ferritic/Super-Ferritic: 430, 439
Duplex/Lean Duplex: 2101, 2205, 2507
High Nickel: AL-6XN^®, 600, 625, 800, 825, C-276, C-22
PH Grades: 17-4, 17-7
Specialty: E-Brite^®, Nitronic 30/40, Alloy 20, Invar 36, 718, 21-6-9

Downloads & Resources

File	Language	Size
Extruded Engineered Shapes and Cold Drawn Shapes	EN	406 KB
Precision Cold Drawn Net Shapes Brochure	EN	256 KB
Plymouth Heat Exchanger Tubing	EN	419 KB
Selecting Tubing Materials for Power Generation Heat Exchangers	EN	265 KB
Plymouth^® Product Catalog	EN	4 MB

Tubing and Engineered Shapes for Nuclear Power

Tubing and Engineered Shapes for Nuclear Power

Plymouth® Nuclear Power Products

Cold Drawn Shapes

Cold Drawn Shape Specifications

Seamless Stainless Steel Tubing

Seamless Stainless Steel Pressure Tubing

Seamless Stainless Steel Commercial Instrumentation Tubing

Mechanical Properties

Alloys

Seamless Nickel Alloy Tubing

Nickel Alloy Pressure Tubing

Nickel Alloy Commercial Instrumentation Tubing

Welded Nickel Alloy Tubing

Welded Nickel Alloy Pressure Tubing Specifications

Welded Stainless Steel Tubing

Welded Stainless Steel Pressure Tubing

Welded Stainless Steel Nuclear Instrumentation Tubing

Mechanical Properties

Alloys

Downloads & Resources

More than 100 Years of Innovation, Quality, and Custom Solutions

Plymouth^® Nuclear Power Products