ASTM A815 UNS S31803 Equal Tee

WP-S UNS S31803 Equal Tee

Singapore client purchased some 12” ASTM A815 WP-S UNS S31803 Equal Tee with other Duplex Steel Pipe Fittings from us. Let’s the more details.

By this chance we would like to introduce what is ASTM A815 WP-S UNS S31803 Equal Tee and its applications this time.

Purchase Order

NO.	DESCRIPTION
1	12″ PIPE SEAMLESS PE ASME B36.19M ASTM A790 UNS S31803 SCH60
2	12″ ELBOW 45DEG. LR, SEAMLESS, ASME B16.9, BE, ASTM A815 WP-S/WX UNS S31803, LOW TEMP, SCH60
3	12″ ELBOW 90DEG. LR, SEAMLESS, ASME B16.9, BE, ASTM A815 WP-S/WX UNS S31803, LOW TEMP, SCH60
4	12″ FLANGE BLIND, ASME B16.5, CL 900, RFFE, ASTM A182 GRADE F51, LOW TEMP
5	12″ FLANGE WN, ASME B16.5, CL 900, RFFE, ASTM A182 GRADE F51, LOW TEMP, SCH60
6	12″ X 3/4″ FLANGOLET, MSS SP-97, CL 1500, RFFE, ASTM A182 GRADE F51, LOW TEMP, SCH60 X SCH40S
7	12″ X 1.1/2″ FLANGOLET, MSS SP-97, CL 1500, RFFE, ASTM A182 GRADE F51, LOW TEMP, SCH60 X SCH40S
8	12″ X 2″ FLANGOLET, MSS SP-97, CL 1500, RFFE, ASTM A182 GRADE F51, LOW TEMP, SCH60 X SCH40S
9	12″ TEE EQUAL, SEAMLESS, ASME B16.9, BE, ASTM A815 WP-S UNS S31803, LOW TEMP, SCH60 X SCH60
10	12″ X 6″ TEE REDUCING, SEAMLESS, ASME B16.9, BE, ASTM A815 WP-S/WX UNS S31803, LOW TEMP, SCH60 X SCH40S

ASTM A815 UNS S31803 Tee

Equal Tee ASTM A815 WP-S UNS S31803 is a Duplex Stainless Steel Tee. It is ferrite or austenite stainless steel with a microstructure of 50:50.

From the description, we can know A815 is the standard code, WP is grade, S31803 is the UNS code.

Because of it is the mixture of ferrite and austenite, so it has the characteristics of both. In most instances, duplex stainless steel is tougher than ferrite stainless steel. And in some cases, its strength even is twice of austenite. Duplex steels are also magnetic, which is much different from common austenite.

What is ASTM A815?

It is standard specification for Wrought Ferritic, Ferritic/Austenitic, and Martensitic Stainless Steel Piping Fitting.

This specification covers two general classes, WP and CR. Class WP fittings are subdivided into four classes:

• WP-S, seamless products.
• WP-W, welded products.
• WP-WX, Pipe fittings which contain welds where all welds have been radiographed.
• WP-WU, fittings that contain welds where all welds have been ultrasonically tested.

So, the ASTM A815 WP-S Equal tee is a Seamless Wrought Ferritic/Austenitic Duplex Steel Pipe Fitting.

Seamless & Welded A815 UNS S31803 Duplex Steel Pipe Fittings.

ASTM A815 Duplex Steel UNS S31803 Buttweld Equal Tee

Equal Tee begins as cast material, then rolled to the shape after reheating. This process is wrought. Most Butt Weld Fittings is also wrought fittings. So, UNS S31803 Equal Tee is one type of ASME B16.9 Butt Weld Fittings.

Another reason for Butt Weld Equal Tee is the size. Only butt weld fittings can be 12 inch which is a quite large size. The largest size of Forged Fittings is 4 inch. And the schedule Sch 60 is usually to describe thickness of butt weld fittings.

By the way, wrought and forge has the same meaning in Chinese, but they are a little different. Forged steels are tougher than wrought steels, so Butt Weld Equal Tee is not very common used in high-tension applications.

As we all know, butt weld fittings have two categories: duplex steel Seamless and Welded Pipe fittings.

Seamless A815 Duplex Steel Pipe Fittings

According to ASTM A815, Class WP-S fittings should be manufactured from seamless product.

Seamless Pipe Fittings ordered as Class WP-S shall of seamless construction and shall meet all requirements of specification A960/ A960M, which are for Common Requirements of Wrought Steel Piping Fittings. The seamless construction makes the equal tee strong.

UNS S31803 Equal TEE

Working Temperature

UNS S31803 has a high content of chromium, making the equal tee has good corrosion resistance. Even in chloride and sulphide environments, it exhibits very high resistance to stress corrosion cracking. But it will causes embrittlement at temperatures over 300°C.

Besides, UNS S31803 Equal TEE has good strength and elongation. And at low temperature, its notch ductility is better than ferritic and martensitic grades. Its working temperature at least is -50°C.

So this kind of stainless steel fittings is ideal for low temperature applications.

Duplex Steel Butt Weld Fittings are typically used in:

• Chemical processing, transport and storage
• Oil and gas exploration and offshore rigs
• Marine environments
• Pollution control equipment

UNS S31803 Tee Chemical Composition %

C	Mn	P	S	Si	Ni	Cr	Mo	N
0.03	2.00	0.03	0.02	1.00	4.5-6.5	21-23	2.5-3.5	0.08-0.20

UNS S31803 Tee Mechanical Properties

Yield Strength MPa	Tensile Strength MPa	Elongation min %	HB max
66/450	90/620	20.0	290

ASTM A815 UNS S31803 Duplex Steel Pipe Fittings,

Duplex steel ASTM A815 Fittings Weldability

As a Butt Weld Equal Tee, the weld-ability is important. ASTM A815 Duplex Steel Equal Tee has good weld-ability.

Though the weld-ability of UNS S31803 Butt Weld Fittings is not as good as Austenite, but its low thermal expansion can reduce the deformation and residual stress after welding.