Description

SSAW Steel Pipe, also known as spiral submerged arc welded steel pipe, is a type of welded steel tube made by rolling narrow steel strips into large-diameter pipes. The spiral weld seam improves overall mechanical properties, reduces cost, and is suitable for medium- and high-pressure fluid transportation and structural applications. However, the weld seam is relatively long, requiring strict quality control.

Features of SSAW Steel Pipe:

1. Flexible forming and wide specification coverage: SSAW Steel Pipe can be produced from narrower steel strips to create large-diameter (φ219–φ3620mm) and thick-walled (6–25.4mm or even higher) pipes. The same blank can be used to accommodate various pipe diameters, making it particularly suitable for large-diameter pipelines.

2. Superior stress distribution in the spiral weld seam: The SSAW Steel Pipe weld seam is continuously distributed in a spiral pattern. Compared to straight-seam welded pipes, it has lower combined stress when subjected to internal pressure or axial/circumferential combined stress, allowing for a reduction in wall thickness of approximately 10%–25% under the same pressure.

3. Mature technology and lower cost: SSAW Steel Pipe uses room-temperature spiral forming + double-sided submerged arc welding (SAWH). Equipment investment and energy consumption are lower than some straight seam welding processes, making it suitable for large-scale production and offering an overall cost advantage.

4. Good pressure resistance and toughness: SSAW Steel Pipe undergoes 100% non-destructive testing (ultrasonic + X-ray) and hydrostatic testing. Steel grades can reach X70/X80, with burst pressure exceeding 26MPa. It combines high strength with good toughness, making it suitable for pressure pipelines such as oil and gas, water supply and drainage, and heating systems.

5. Residual stress and weld quality are key control points: SSAW Steel Pipe forming and welding easily generate residual stress (high-grade steels such as X80 require mechanical diameter expansion to alleviate this). The weld length is 30%–100% longer than straight seam pipes, requiring high stability in the welding process and prevention of defects such as “saddle-shaped” internal welds and “fishback” external welds.

6. Strong Corrosion Adaptability: SSAW Steel Pipes can be fitted with 3PE, epoxy coal tar, galvanized, and other anti-corrosion layers on the outer wall, and cement mortar or epoxy lining on the inner wall, meeting the needs of buried, overhead, and corrosive environments (such as chemical and coastal areas).

7. Wide Structural Applications: In addition to fluid transportation, SSAW Steel Pipes are also used for piling pipes, bridge piers, and dock structures, but not directly for high-rise building load-bearing frames (requires integration with concrete or special design).

Compared to straight seam welded pipes (ERW steel pipe/LSAW), spiral welded steel pipes offer superior cost-effectiveness in large-diameter, medium-to-low pressure applications, but have longer weld seams and slower production speeds.

Applications of SSAW Steel Pipe:

SSAW Steel Pipes are mainly used in two major areas: pressurized fluid transportation and structural load-bearing. Specifically, they include:

1. Oil and Gas Transportation: Long-distance oil and natural gas pipelines and urban gas pipeline networks (compliant with standards such as SY/T 5037, GB/T 9711, and API 5L). Large-diameter (e.g., DN600–DN3000) SSAW Steel Pipes are the primary choice due to their spiral weld distribution, high pressure resistance, and large single-piece length.

2. Municipal Water Supply and Drainage and Sewage Treatment: SSAW steel pipes are used for water supply, rainwater/sewage discharge, and heating networks (often internally coated with cement mortar or externally covered with 3PE/epoxy coal tar pitch for corrosion protection). They are corrosion-resistant and suitable for large flow rates.

3. Water Conservancy Projects: Water diversion canals, drainage pumping stations, water pipelines in dike reinforcement, and structural pile foundations (such as the Yangtze River and Xiaolangdi projects).

4. Building and Bridge Engineering: SSAW Steel Pipe is used as pile foundation pipe (spiral steel pipe for piling, conforming to SY/T 5040), structural support columns, wharf and culvert engineering, with high-strength steel (such as Q345B, L360) meeting load-bearing and bending resistance requirements.

5. Industrial Pipelines: Used for transporting process fluids, steam, and slurry in chemical, power, and metallurgical industries (requiring acid and alkali resistant or wear-resistant linings); also used in some emerging structures such as photovoltaic supports and wind power foundations.

6. Special Structural Applications: Temporary cofferdams, foundation pit support, large stadium roof trusses, etc., utilizing the flexible specifications, uniform wall thickness, and easy welding and installation characteristics of SSAW Steel Pipe.

Standards of Steel Pipe:

Standard	Grade	Chemical Composition(max)%					Mechanical Properties(min)
Standard	Grade	C	Si	Mn	P	S	Tensile Strength(Mpa)	Yield Strength(Mpa)
API 5CT	h40	–	–	–	–	0.030	417	417
	J55	–	–	–	–	0.030	517	517
	K55	–	–	–	–	0.300	655	655
API 5L PSL1	A	0.22	–	0.90	0.030	0.030	335	335
	B	0.26	–	1.20	0.030	0.030	415	415
	X42	0.26	–	1.30	0.030	0.030	415	415
	X46	0.26	–	1.40	0.030	0.030	435	435
	X52	0.26	–	1.40	0.030	0.030	460	460
	X56	0.26	–	1.40	0.030	0.030	490	490
	X60	0.26	–	1.40	0.030	0.030	520	520
	X65	0.26	–	1.45	0.030	0.030	535	535
	X70	0.26	–	1.65	0.030	0.030	570	570
API 5L PSL2	B	0.22	0.45	1.20	0.025	0.015	415	415
	X42	0.22	0.45	1.30	0.025	0.015	415	415
	X46	0.22	0.45	1.40	0.025	0.015	435	435
	X52	0.22	0.45	1.40	0.025	0.015	460	460
	X56	0.22	0.45	1.40	0.025	0.015	490	490
	X60	0.12	0.45	1.60	0.025	0.015	520	520
	X65	0.12	0.45	1.60	0.025	0.015	535	535
	X70	0.12	0.45	1.70	0.025	0.015	570	570
	X80	0.12	0.45	1.85	0.025	0.015	625	625
ASTM A53	A	0.25	0.10	0.95	0.050	0.045	330	330
ASTM A53	B	0.30	0.10	1.20	0.050	0.045	415	415
ASTM A252	1	–	–	–	0.050	–	345	345
	2	–	–	–	0.050	–	414	414
	3	–	–	–	0.050	–	455	455
EN10217-1	P195TR1	0.13	0.35	0.70	0.025	0.020	320	320
	P195TR2	0.13	0.35	0.70	0.025	0.020	320	320
	P235TR1	0.16	0.35	1.20	0.025	0.020	360	360
	P235TR2	0.16	0.35	1.20	0.025	0.020	360	360
	P265TR1	0.20	0.40	1.40	0.025	0.020	410	410
	P265TR2	0.20	0.40	1.40	0.025	0.020	410	410
EN10217-2	P195GH	0.13	0.35	0.70	0.025	0.020	320	320
	P235GH	0.16	0.35	1.20	0.025	0.020	360	360
	P265GH	0.20	0.40	1.40	0.025	0.020	410	410
EN10217-5	P235GH	0.16	0.35	1.20	0.025	0.020	360	360
EN10217-5	P265GH	0.20	0.40	1.40	0.025	0.020	410	410
EN10219-1	S235JRH	0.17	–	1.40	0.040	0.040	360	360
	S275JOH	0.20	–	1.50	0.035	0.035	410	410
	S275J2H	0.20	–	1.50	0.030	0.030	410	410
	S355JOH	0.22	0.55	1.60	0.035	0.035	470	470
	S355J2H	0.22	0.55	1.60	0.030	0.030	470	470
	S355K2H	0.22	0.55	1.60	0.030	0.030	470	470

Standards and Classifications

CLASSFICATION	STANDARD	MAIN PRODUCTS
Steel Pipe for Fluid Service	GB/T 14291	Welded pipe for mine fluid sevice
	GB/T 3091	Welded pipe for low pressure fluid service
	SY/T 5037	Spirally submerged arc welded steel pipe for pipelines for low pressure fluid service
	ASTM A53	Black and hot-hipped galvanized welded and seamless steel pipe
	BS EN10217-2	Welded steel tybes for pressure purposes – delivery technical conditions – part2: Electric welded non- alloy and alloy steel tubes with specified elevated temperature properties
	BS EN10217-5	Welded steel tybes for pressure purposes – delivery technical conditions – part5: submerged arc welded non-alloy and alloy steel tubes with specified elevated temperature properties
Steel Pipe for Ordinary Structure	GB/T 13793	Longitudinally electric resistance welded steel pipe
	SY/T 5040	Spirally submerged arc welded steel pipe piles
	ASTM A252	Welded and seamless steel pipe piles
	BS EN10219-1	Cold formed welded structural hollow sections of non-alloy and fine grain steels – part1: Technical delivert conditions
	BS EN10219-2	Cold formed welded structural hollow sections of non-alloy and fine grain steels – part2: tolerances dimmsions and sectional properties
Line Pipe	GB/T 9711.1	Steel pipe for pipeline transportation system of petroleum and natural gas industries(Class A steel pipe)
	GB/T 9711.2	Steel pipe for pipeline transportation system of petroleum and natural gas industries(Class B steel pipe)
	PSL1/2	Line pipe
Casing	API 5CT/ ISO 11960 PSL1	Steel pipe for use as casing or tubing for wells of petroleum and natural gas industries

Thickness	5.2MM~30MM
Width	219MM~3000MM
Grade	10#-45#, 16Mn, A53-A369, Q195-Q345, ST35-ST52
Standard	(1)GB/T9711, API5L, ISO3183,(PSL1:A/L210、B/L245、X42/L320、X52L360、X60/L415、X65/L450、PSL2: BN/L245N、X42N/L290N、X64N/L320N、/X52N/L360N、X56N/L390N、X60N/L415N、X65N/L450N、X70N/L485N、X80N/L555N、BM/L245M、X42M/L290M、X46M/L320M、X52M/L360M、X56M/L390M、X60M/415M、X65M/L485M、X80M/L555M) (2)ASTM A252（GR.1、GR.2、GR.3） (3)EN10217-5 (P195TR1、P235TR1、P265TR1、P195TR2、P235TR2、P265TR2) (4)EN10217-1 (P235GH、P265GH) (5)EN10219-1/2 (S235JR、S275J0、S275J2、S355J0、S355J2、S355KJ2) (6)SY/5037 （Q195、Q215A、Q215B、Q235A、Q235B、Q345A、Q345B） (7)SY/5040 （Q235B、Q345B）
Surface Treatment	3PE FBE