This specification covers the 8 and 9% nickel-alloy steel forged or rolled flanges, fittings, valves, and parts intended for use in welded pressure vessels for low-temperature service. Two types of materials are specified according to the chemical composition: type I and type II. Materials for forgings shall consist of ingots, or either forged or rolled blooms, billets, or bars. Except for all types of flanges, elbows, return bends, tees, and header tees, other parts including NPS 4 may be machined from hot-rolled or forged bar. The steel shall conform to the specified chemical requirements for carbon, manganese, phosphorus, sulfur, silicon, and nickel. The following methods of heat treatment shall be used: quenched and tempered and double normalized and tempered. Two tests shall be done to meet the mechanical requirements of the material: tension test and Charpy impact test.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This specification covers 8 and 9 % nickel-alloy steel forged or rolled flanges, fittings, valves, and parts intended for use in welded pressure vessels for low-temperature service. The specification is applicable to forgings with maximum section thickness of 3 in. [75 mm] in the double normalized and tempered condition and 5 in. [125 mm] in the quenched and tempered condition. Forgings under this specification are intended for service at operating temperatures not lower than −320 °F [−196 °C] for Type I or −275 °F [−170 °C] for Type II or higher than 250 °F [121 °C].

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

Keywords

low temperature applications; nickel alloy steel; pipe fittings; steel; piping applications; pressure containing parts; steel flanges; steel forgings; alloy; steel valves; Pressure vessel steel; Steel fittings--specifications; Nickel alloy flanges/fittings/valves/parts--specifications;

ICS Code

ICS Number Code 23.040.40 (Metal fittings)

Citing ASTM Standards

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