EN 10253-1 Carbon Steel Butt Weld Pipe Fittings

1. General introduction

EN 10253-1 standard covers factory-wrought carbon steel butt welding pipe fittings including elbows, return bends, concentric and eccentric reducers, equal and reducing tees, dished ends and caps which are delivered without specific inspection. EN 10253-1 is derived from relative DIN pipe fitting standard series which are now obsolete. These butt welding pipe fittings can be either manufactured via hot or cold deformation from raw material(starting products) such as seamless tubes, welded tubes, plates, forgings and bars. This manufacturing process of the base material is at the discretion of the manufacturer.

2. Metallurgical properties

Usually, the steel grade applied to EN 10253-1 butt weld pipe fittings is S 235. There is another alternative steel grade S 265 covered by EN 10253-1 according to Annex A.

1-1) Chemical requirements of steel grade S 235

Steel Grade	C (%) Max.	Si (%) Max.	Mn (%) Max.	S (%) Max.	P (%) Max.
S 235	0.16	0.35	1.2	0.025	0.030

*Elements not included in this table shall not be intentionally added to the steel without

agreement of the purchaser, with the exception of elements used for deoxidation.

However, residual elements may be tolerated provided that the mechanical properties

and applicability are not adversely affected.

1-2) Mechanical properties of steel grade S 235

Steel Grade	Yield Strength min. MPa	Tensile Strength min. MPa	A min. %	HB max.
S 235	235	360~500	25	170

*Mechanical properties shall be measured at room temperature and be determined on the

finished product or base material provided it is in the same heat treatment condition as the

fitting it represents.

2-1) Chemical requirements of steel grade S 265

Steel Grade	C (%) Max.	Si (%) Max.	Mn (%) Max.	S (%) Max.	P (%) Max.
S 265	0.20	0.40	1.40	0.025	0.030

*Elements not included in this table shall not be intentionally added to the steel without

agreement of the purchaser, with the exception of elements used for deoxidation.

However, residual elements may be tolerated provided that the mechanical properties

and applicability are not adversely affected.

2-2) Mechanical properties of steel grade S 265

Steel Grade	Yield Strength min. MPa	Tensile Strength min. MPa	A min. %	HB max.
S 265	265	410~570	21	180

*Mechanical properties shall be measured at room temperature and be determined on the

finished product or base material provided it is in the same heat treatment condition as the

fitting it represents.

All the butt-weld pipe fittings according to EN 10253-1 are weldable. Pipe fittings produced by cold deformation shall be subsequently normalized. Pipe fittings produced by hot deformation may be delivered without heat treatment if hot deformation produces a technically equivalent metallurgical structure with the mechanical properties indicated in table 1-2) and 2-2).

Related articles: Dimensional tolerances and end finishing of EN 10253-1 pipe fittings.

Inspection and testing for EN 10253-1 butt weld pipe fittings.

Marking, coating & packaging of EN 10253-1 pipe fittings.

Views: Author：hbmetals Date:15/07/22