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Root Cause Analysis of Microstructural Abnormalities and Low Hardness in a P91 Elbow
Posted: 01/24/2026 03:57:38 Hits: 6Abstract This study investigates abnormally high local hardness and metallographic microstructure observed in a high-temperature reheat steam pipeline elbow fabricated from SA335 P91 steel in a power plant. The chemical composition, wall thickness, hardness, and microstructure of the elbow... -
Effect of Flow Velocity on Liquid Flow Structure and Particle Motion in Pipe Bends
Posted: 12/30/2025 02:29:04 Hits: 115.1.1 Evolution of the Flow Field in the Bend The influence of flow velocity on the flow field characteristics within the pipe bend was investigated while the bend diameter ratio and solid particle concentration were kept constant. A bend diameter ratio of R/D = 3.5 and a solid particle concentration... -
Pipeline Erosion from Ammonium Chloride Crystallization in Catalytic Cracking Units
Posted: 11/29/2025 05:23:08 Hits: 21Abstract: This study investigates pipe perforation and leakage caused by erosion from ammonium chloride crystallization in the top circulation system of heavy-oil catalytic cracking units. By analyzing the erosion and wear behavior of salt crystallization, areas prone to perforation are identified,... -
σ Phase Formation and Microstructure in Austenitic Heat-Resistant Steel Pipe Joints
Posted: 10/30/2025 11:12:32 Hits: 26Abstract: This study investigates the formation of the σ phase in austenitic heat-resistant steel pipe joints used in power plant boilers. Results show that different morphologies of the σ phase precipitate in austenitic steel joints after high-temperature aging. The formation... -
Cause Analysis and Solutions for Ethylene Pipeline Elbow Corrosion
Posted: 10/25/2025 10:27:15 Hits: 15Abstract: During a scheduled inspection at a petrochemical plant, pitting corrosion was detected in the base material of a TP304 ethylene pipeline elbow. To determine the cause and develop effective countermeasures, a comprehensive analysis was conducted, including evaluation of the base material’s... -
Failure Analysis of Heat Exchanger Tube Elbows in Thermal Power Plants
Posted: 09/22/2025 11:25:14 Hits: 30Abstract In a thermal power plant project, small-diameter serpentine heat exchanger tubes were fabricated from 20G steel with dimensions of Ø25 × 3 mm, a bend angle of 180°, and a bend radius of 27.2 mm. The tubes were formed using a CNC top-roll tube bender. However, during the... -
Pipe Cap Hot-Forming: Heating Temperature and Blank Size Study
Posted: 09/04/2025 12:09:20 Hits: 24Abstract: A numerical simulation study of pipe cap hot forming was conducted using DEFORM-3D finite element analysis software to determine the optimal heating temperature and dimensions of the pipe cap blank. The results offer valuable guidance for the design and manufacturing of pipe caps. Pipe... -
Elbow Crack and Leakage in a High-Temperature Reheat Steam Drain Tank Sampling Pipeline
Posted: 07/29/2025 12:28:59 Hits: 41Abstract: A leakage occurred in the elbow section of the sampling pipeline connected to the liquid level gauge of a high-temperature reheat steam drain tank in a thermal power plant during normal operation. The root cause of the elbow failure was investigated using macroscopic observation, chemical... -
Fracture Analysis of Reheat Drain Pipe Elbow in Ultra-Supercritical Unit
Posted: 07/14/2025 11:47:32 Hits: 46This study investigates the cause of fracture in the reheat hot section drain pipe elbow of a 1000 MW ultra-supercritical thermal power unit on the B-side. A series of experimental analyses, including macroscopic morphology, metallographic structure, hardness, and mechanical property tests, were... -
Root Cause Analysis of Elbow Cracking in Hydrogen Unit Condensate Piping
Posted: 06/25/2025 07:34:35 Hits: 33Abstract: A crack was found in the 321 stainless steel elbow of the condensate pipeline serving the hydrogen production unit at a petrochemical plant, resulting in medium leakage. The failure was investigated through metallographic examination, scanning electron microscopy, energy-dispersive... -
Failure Analysis of Carbon Steel Elbow in Power Station Main Steam Pipe
Posted: 06/16/2025 04:48:50 Hits: 56Abstract: To enhance boiler safety, this paper analyzes a failure incident in the main steam pipe elbow of a self-contained power station boiler at a chemical fiber plant, caused by the improper use of carbon steel, which resulted in fracture and leakage. Through macroscopic inspection, wall... -
Cracking Analysis of Outer Casing Elbow in Nuclear Hydrogen Pipes
Posted: 05/27/2025 05:11:03 Hits: 21Abstract During the operation of a nuclear power plant, repeated leakage occurred at the outer casing elbow of the double-walled pipe in the hydrogen supply system. To determine the cause, the cracked elbow was examined through macroscopic inspection, microstructural analysis, chemical composition testing,...