ASTM A335 Grade P91 Alloy Steel Seamless Pipe

• After-sales Service: Technical/Sample/Quality
• Type: Seamless/Welded
• Technique: Hot-Rolled/Cold-Drawn
• Material: Carbon/Alloy/Stainless
• Surface Treatment: Black&Varnish Coating&3lpe&PE
• Usage: Boiler Pipe
• Model NO.: P91
• Section Shape: Round
• Transport Package: as Required
• Specification: 10-850mm
• Trademark: SHUNFU
• Origin: China
• HS Code: 7304193000
• Production Capacity: 30000tons/Year

Product Description

ASTM A335 Grade P91 Alloy Steel Seamless Pipe

ASTM A335 is a standard specification for seamless ferritic alloy-steel pipe for high-temperature service. The specification generally covers chrome-moly seamless pipes with remarkable resistance to corrosion and good tensile strength at high-temperature service.

P91 is a chrome moly alloy metal that contains excellent strength and temperature resistance. It is designed for enhanced creep strength, making it a creep strength enhanced ferritic (CSEF). This metal is made by normalizing at 1050 °C, air cooling to 200 °C, and then tempered through heating to 760 °C.
 

P91 Pipe Chemical Requirements

C, %	Mn, %	P, %	S, %	Si, %	Cr, %	Mo, %	V, %	N, %	Ni, %	Al, %	Nb, %
0.08-0.12	0.3-0.6	0.02 max	0.01 max	0.2-0.5	8.0-9.5	0.85-1.05	0.18-0.25	0.03-0.07	0.4 max	0.04 max	0.06-0.10

 

P91 Pipe Applications

A335/SA335 P91 is suitable for bending, flanging (vanstoning), and similar forming operations and for fusion welding. P91 is most commonly used in the power industry and petrochemical plants where fluids and gases are transported at extremely high temperatures and pressures. P91's strength and high temperature endurance makes it ideally suitable for plants that operate on a cyclic basis - like combined cycle plants. Also, the reduction in thickness suits HRSG designers, in an HRSG the temperature head is limited and locating the coils in the heat transfer path is very critical.
P91 is the correct grade for:
Power generation
Petrochemicals
Gas processing
Petrochemical Plants
Heaters
Oilfield services
 

Tesile Chart of A335 P91 Material

	Seamless Pipe
	P5	P9	P11	P22	P91
Tensile Strength, min ksi	60	60	60	60	85
Tensile Strength, min MPa	415	415	415	415	585
Yield Strength, min ksi	30	30	30	30	60
Yield Strength, min MPa	205	205	205	205	415

 

Material & Manufacture

Pipe may be either hot finished or cold drawn with the finishing heat treatment noted below.
 

Heat Treatment Requirements

Grade	Heat Treatment Type	Normalizing Temperature Range F [C]	Subcritical Annealing or Tempering Temperature Range F [C]
P91 (type 1 and 2)	Normalize and Temper, or	1900-1975 [1040 - 1080]	1350-1470 [730 - 800]
	Quench and Temper	1900-1975 [1040 - 1080]	1350-1470 [730 - 800]

 

The testing requirements for these pipes include the following:

*Transverse/longitudinal: tension and flattening, hardness, bend tests-for material which has been heat-treated in batch furnaces, these tests shall be made on the S% of the pipes from each heat lot number. For smaller lots, one pipe at a minimum has to be tested
*ASTM A335 Gr.P91 shall have a hardness of 250 HB/265 HV(25 HRC)
*Hydro testing: Each length of pipe shall be subjected to the hydrostatic test. Also, each pipe shall be examined by a non-destructive examination method in accordance to the required practices.
*The non-destructive electric test is optional

The nondestructive test (NDT) shall be performed in accordance with Practice E 213, Practice E 309, or Practice E 570. These NDT methods includes: Ultrasonic Examination, which shall be performed to detect both longitudinally and transversely oriented discontinuities; Eddy Current Examination, which has the capability to detect significant discontinuities especially of short abrupt type; Flux Leakage Examination, which is capable of detecting the presence and location of significant longitudinally and transversely oriented discontinuities
 

Packaging & Shipping

ASTM A335  Steel Pipes may be furnished bare or coated and with capped ends. Tubes and pipes up to 3" OD will be supplied in bundles. In order to prevent rust during sea shipment, bundles of ASTM A335  tubes may be wrapped with polypropylene sheets, and secured with flat steel bands. Over 3" OD will be supplied loose.