ASTM A376 TP347H Seamless Steel Pipe for Power Plant

ASTM A376 TP347H is a seamless stainless steel tube designed for high-temperature environments in power plants, such as superheaters, reheaters, and boiler tubes. It is an austenitic stainless steel stabilized with niobium and tantalum, offering superior corrosion and oxidation resistance, as well as higher high-temperature strength and creep resistance compared to standard 347 steel. The "H" in TP347H indicates a higher carbon content, improving its mechanical properties at high temperatures.

We offer a variety of sizes of ASTM A376 TP 347/347H 304 321 seamless stainless steel tubes, with outer diameters from 1/2 inch to 30 inches and wall thickness grades of SCH5S, 10S, 40S, and 80S. Average wall thickness can be customized to customer requirements. We manufacture ASTM A376 347/347H stainless steel seamless tubes using a cold-working process, followed by heat treatment, pickling, and passivation. Ends can be beveled or flat.

ASTM A376 TP347H Stainless Steel Seamless Pipe for High Temperature

ASTM A376 Seamless Stainless Steel Pipe shall be free of scale and contaminating iron particles. Pickling, blasting, or surface finishing is not mandatory when pipe is bright annealed. The purchaser may request that a passivating treatment be applied.

ASTM A376 TP 347/347H Seamless Stainless Steel Pipe

Standard	ASTM A376
Stainless Steel	304, 316, 321, 347, 347H
Pipe Type	Seamless Pipe
Finishes	Annealed pickling, bright annealing
Outside Diameter	1/8 Inch To 30 Inch, NPS
Thickness	Sch 5, Sch 5S, Sch 10S, Sch 40S, Sch 80S, Sch 160
Application	high-temperature central-station service

Chemical Composition of TP347H (UNS S34709)

Element	Requirement (%)	Notes
Carbon (C)	0.04–0.10	Controlled for high-temperature stability
Manganese (Mn)	2.00 max
Phosphorus (P)	0.045 max
Sulfur (S)	0.030 max
Silicon (Si)	1.00 max
Nickel (Ni)	9.0–13.0	Austenite stabilizer
Chromium (Cr)	17.0–19.0	Oxidation resistance

Mechanical Properties of TP347H (UNS S34709)

Property	Requirement
Grade	TP347H
UNS Designation	S34709
Tensile Strength, min	75 ksi [515 MPa]
Yield Strength, min	30 ksi [205 MPa]
Elongation in 2 in.., min	35% (Longitudinal)

ASTM A376 TP347H Stainless Steel Seamless Pipe Application

Power Generation: Superheaters, reheaters, and boiler tubes in coal-fired/thermal plants.

Petrochemical: Catalytic cracker units, furnace manifolds, and reformer tubes.

Aerospace: Exhaust systems and heat exchangers.

Nuclear: Steam generator tubing and pressurizer components.

Industrial Processing: High-temperature fluid transfer systems.

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Testing and Inspection

All pipes shall be furnished in the heat-treated condition unless the order specifically states that no final heat treatment shall be applied. Tensile tests, hydrostatic test, nondestructive electric tests, ultrasonic tests, eddy-current tests, tension tests, and flattening tests shall be made to conform to the requirements specified.