Standard Specification for Pressure Vessel Plates, Carbon Steel, for Moderate- and Lower-Temperature Service
Brown McFarlane holds large stocks of plates certified to ASTM A516 Gr. 70 and ASME SA516 Gr. 70 in its warehouse facilities in the U.K. A range of specially manufactured hydrogen induced crack resistant steel in SA / A516 Gr. 70 HIC is also available from stock. These are steel specifications that are at the core of our range and we consider ourselves to be experts in these products. Why not put us to the test? Please contact us with your technical questions and your buying enquiries.
The A516 / SA516 standard, its full name is “Standard Specification for Pressure Vessel Plates, Carbon Steel, for Moderate- and Lower-Temperature Service”, could almost be described as the default material specification for pressure vessel applications particularly outside of Europe and it is widely used by designers and engineers in many market sectors. You may also see the following variations:
ASTM A516 Grade 70N or ASME SA516 Grade 70N (the “N” is added to show that the steel is normalise)
ASTM A516M or ASME SA516M (the “M” indicates that the material is certified in metric units)
ASME or ASTM?
So what is the difference between ASTM A516 Gr. 70 and ASME SA516 Gr. 70? In fact the mechanical and chemical properties of the steels are identical and it is the producer of the standard that is the key difference. ASTM, the American Society for Testing and Materials, produces standards that define limits and parameters on a product’s properties and the methods of testing those properties. ASME, the American Society of Mechanical Engineers, specifies materials to be used in the manufacture and construction of particular items. The relevance of this to pressure vessels is that ASME publishes design codes and standards for the manufacture of vessels and within these a particular material standard will be endorsed. ASME “acquires” ASTM specifications in this way and its pressure vessel code committee assigns an “S” to the relevant ASTM standard. So A516 becomes SA516 when ASME acquires it.
ASME SA516 Gr. 70 / ASTM A516 Gr. 70 - the specification
Despite its wide use and application, A516 / SA516 is a remarkably straightforward standard in its basic form with just five key chemical elements specified along with three mechanical properties. It does not even need to be heat treated in any way.
Additional Properties - ASME SA20 / ASTM A20
In many cases the stringent requirements of engineers and designers require much greater controls than this and these are in part provided by a specification called ASTM A20 or ASME SA20 (Specification for General Requirements for Steel Plates for Pressure Vessels). This specification outlines the testing and retesting methods and procedures, permissible variations in dimensions and mass, quality and repair of defects, marking, loading, and ordering information. It also contains a list of supplementary requirements which can be added to the basic A516 / SA516 specification when additional control, testing, or examination is required to meet end use requirements.
The supplementary requirements in A20 / SA20, there are seventeen of them, are designated numbers (S1, S2, S3, and so on) and cover things like ultrasonic testing (S8, S11 or S12 depending on the type of ultrasonic test), charpy v-notch impact tests (S5), and product chemical analysis (S2).
As a matter of course, and in order to provide the best possible service to our customers, Brown McFarlane stocks ASTM A516 Gr. 70 and ASME SA516 Gr. 70 plates with numerous supplementary requirements included and all noted on the material test certificate supplied with each plate.
Although it is not uncommon to see this on steel company web sites, any suggestion that one steel specification and grade is an equivalent to another should be treated with caution especially because of differences in the methodology and techniques used for testing. However ASTM A516 Gr. 70 and ASME SA516 Gr. 70 are broadly similar to the following steel specifications:
Plates certified to these standards are held in stock by Brown McFarlane.
|Carbon (max)||12.5 mm and under||0.27||A, B, C|
|over 12.5 to 50 mm||0.28||A, B, C|
|over 50 to 100 mm||0.30||A, B, C|
|over 100 mm||0.31||A, B, C|
|Manganese||0.85 - 1.20||A, C|
|0.79 - 1.30||B, C|
|Phosphorus (max)||0.025||A, B|
|Sulphur (max)||0.025||A, B|
|Silicon||0.15 - 0.40||A|
|0.13 - 0.45||B|
|Tensile Strength, MPa (ksi)||485 - 620 (70 - 90)|
|Yield Strength, min MPa (ksi)||260 (38)|
|Elongation min, % 200 mm (8 in)||17|
|Elongation min, % 50 mm (2 in)||21|