Stainless Steel Seamless Pipe Distributor

As we all know ASTM A312 TP321 Seamless Pipe is one of the most popular austenitic stainless steel pipe for high-temperature and general corrosive service. It can be used in many industries like oil and gas, water, mineral slurry transmission and structural purposes. So what is SS 321 pipe and why it is required so large quantities in different industrial activities? First, let’s see what is ASTM A312?

ASTM A312 Industrial Pipe Specifications

ASTM A312 is the standard specification for Seamless, Welded and Heavily Cold Worked Austenitic Stainless Steel Pipes.

Seamless pipe shall be made by a process that does not involve welding at any stage of production. Welded pipe shall be made using an automatic welding process with no addition of filler metal during the welding process. And heavily cold-worked pipe shall be made by applying cold working of not less than 35% reduction in thickness of both wall and weld to a welded pipe prior to final anneal.

And materials under this specification shall conform to the applicable requirements of the current edition of specification A999/A999M, which is the general specification for alloy and stainless steel pipe, unless otherwise provided herein. The pipes it included intended for high-temperature and general corrosive service.

ASTM A312 TP321 Seamless Pipe Application

• Oil & Gas
• Heat Exchanger
• Pharmaceuticals
• Chemicals
• Water Treatment
• Food Processing
• Construction
• Shipbuilding
• Ports
• Railway
• Nuclear Power

Stainless Steel 321 Seamless Pipe

A312 TP321 Seamless Pipe often referred to as a marine grade stainless steel because of its effective resistance to chloride corrosion in comparison to other grades. It is an austenitic grade pipe with the addition of 2-3% molybdenum which further improves corrosion resistance. In this standard also has TP321H, which has high carbon content that for better high temperature creep property. Both TP321 and TP321H have lower strength requirements for pipe manufactured in nominal wall thicknesses greater than 3/8 in. [9.5 mm].

SS 321 pipes have a good performance in high temperature, corrosive environment, and it also has excellent weldability. So they are very popular and available in wide range of industries.

ASTM A312 321 Chemical Composition

C	Mn	Si	P	S	Cr	Ni
0.08	2.00	1.00	0.045	0.030	17.0 19.0	9.0 12.0

ASTM A312 321 Mechanical Properties

Tensile Strength	Yield Strength	Elongation
515 (MPa) min	205 (MPa) min	40 (% ) min

A312 TP321 Seamless Pipe Dimensions

• Diameter

This standard covers seamless pipe form NPS 1/2 to NPS 30. Its outside diameter in inch is form 0.405 to 30.

• Schedules

Usually we use schedule to refer to the wall thickness of a pipe. The schedules are Sch 5S, 10S, 40S and 80S. Generally speaking, the specific vales of wall thickness you can refer to ANSI B36.10 (American National Standard for Welded and Seamless Wrought Steel Pipe). Schedule 5S and 10S do not permit threading in accordance with the American National Standard for Pipe Threads (ANSI B1.20.1).

• Length

All sizes are available in a length up to 24 ft with the permitted range of 15 to 24 ft. Short lengths are acceptable, the minimum length shall be agreed upon between the manufacturer and the purchaser. No pipe shall be more than 1/4 in ( 6 mm) over the specified length.

Stainless Steel 321 Seamless Pipe Equivalent

Sometimes people use UNS S32100 to instead of A312 TP321. What are they called in different area?

Grade	Old British		Euro-norm		Swedish SS	Japanese JIS
	BS	En	No	Name
321	321S31	58B, 58C	1.4541	X6CrNiTi18-10	2337	SUS 321