Composition:
• Coal (C): de 2.53% a 4%
• Silicon (Si): de 1% a 3%

ASTME	DIN EN	old DIN
A48 20B/25B	EN 1561 EN-GJL-150	DIN 1691 GG-15
A48 25B/30B	EN 1561 EN-GJL-200	DIN 1691 GG-20
A48 35B/40B	EN 1561 EN-GJL-250	DIN 1691 GG-25

Gray Iron Casting standard for valves

ASTM A126 - 04(2009)
Standard Specification for Gray Iron Castings for Valves, Flanges, and Pipe Fittings
This guide covers standard specification for three classes of gray iron for castings intended for use as valve pressure retaining parts, pipe fittings, and flanges. Chemical analysis shall be performed in each lot and shall conform to the required chemical composition for phosphorous and sulfur. Tension test shall be conducted on each class of gray iron castings and shall conform to the specified values of tensile strength. Tension test specimens shall have threaded ends and shall conform to the prescribed dimensions.

ASTM A278 / A278M - 01(2006)
Standard Specification for Gray Iron Castings for Pressure-Containing Parts for Temperatures Up to 650°F (350°C)
This specification covers gray iron for castings suitable for pressure-containing parts at elevated temperatures. Castings shall be stress-relieved by placing them in a suitable furnace and heating them uniformly to the temperatures and for the times specified. Castings to be used at a particular temperature range shall undergo heat treatment and cooling. Chemical analysis shall be performed on each class of castings and shall meet the maximum requirement for carbon, phosphorus and sulfur. Iron used in supplying castings shall conform to the required tensile strength. Separately cast test bars having the required dimensions shall be poured from the same lot as the castings represented. The test bars shall be cast in dried siliceous sand molds maintained at approximately room temperature. Tension test shall be performed on each lot and materials shall conform to the tensile requirements specified.

ASTM A48 / A48M - 03(2008)
Standard Specification for Gray Iron Castings
This specification covers gray iron castings intended for general engineering use where tensile strength is a major consideration. Castings are classified on the basis of the tensile strength of the iron in separately cast test bars. The surface of the casting shall be free of adhering sand, scale, cracks, and hot tears, as determined by visual examination. The test bars are designated into S, A, B, and C categories, according to the thickness of its controlling wall section. The casting shall be subjected to a tension test to determine its tensile strength