Views: 8 Author: Site Editor Publish Time: 2023-10-25 Origin: Site
ASTM A350 LF2 is a kind of low-temperature carbon steel material, mainly used to manufacture the forged pipe fittings and flanges that can performe better under low-temperature or high-pressure working environent.Blind flanges are generally non-porous in the middle, serving as a barrier and cutoff. Due to their good sealing performance, they are a reliable sealing accessory for pipeline systems.
Of course, there are also special circumstances.Some pipeline systems need to monitor the internal pressure of the pipeline simultaneously, therefore, it is required to drill pressure taps on the blind plates that serve as seals to connect pressure gauges for measurement.Because pressure gauges are typically threaded, the blind plate drilling generally demands NPT threads.
Chemical Composition %
The low-temperature impact test of ASTM A350 LF2 is required to be executed as following specification:
The test temperature for CLASS1 is -46℃. At this time, the average impact toughness AK of the three samples should meet the requirement of ≥20J, and the impact toughness AK value of at least one of the three samples should be ≥16J.
The test temperature for CLASS2 is -18℃. At this time, the average value of the three samples should meet the requirement of impact toughness AK of ≥27J, but there is no mention of the requirement for the minimum impact toughness AK value of the three samples at this time.
In general, the low-temperature impact test requirements for ASTM A350 LF2 are to ensure that the material has good impact resistance under low temperature conditions.
Fourth, the scope of application of ASTM A350 LF2 flanges including:
*Low temperature liquid and gas transportation pipeline systems;
*valves and connections in LNG and petrochemical plants;
*low temperature reactors, separators, condensers;
*other equipment in chemical processes.
The blind flanges’ size ranges at DN15-DN600 (1/2IN-24IN) according to ASME B16.5, and have pressure ratings as Class 150, 300, 400, 600, 900, 1500, 2500.
The blind flanges at the size of DN650-DN1500 (26IN-60IN) follow the ASME B16.47A/B. Applicable pressure levels: Class150, 300, 400, 600, 900.
Flange sealing surface types: raised face (RF), flat face (FF), concave-convex face (MFM), tongue and groove face (TG), ring joint face (RJ), etc. Common sealing surface types include RF, FF, and RTJ.