MUMBAI, India, June 26 -- Intellectual Property India has published a patent application (202331089778 A) filed by Bharat Heavy Electricals Limited on December 29, 2023, for A Device To Estimate Stress Corrosion Cracking Resistance Of Tubes In Tube Sheet Test Block.
Inventors include Nachiappan Manoj Kumar; Sababathy Vijay Murugan; Ramamoorthy Kavirajan; Sundaresan Logesh Kumar; and Arunachalam Santhakumari.
The application for the patent was published on June 19, 2026, under issue no. 25/2026.
Abstract: This invention addresses the pressing concern of stress corrosion cracking in thermal and nuclear power plants, a major failure mode. During the assembly of steam generators, tubes within tube sheets experience stress on their inner surfaces. To replicate the corrosive environment and high temperatures encountered in real-world service, a novel testing apparatus has been developed, based on ASTM G36 guidelines but tailored for testing the inner diameter (ID) of tubes within tube sheet test blocks. The apparatus employs corrosive agents, such as boiling 45wt% MgCl2 or 3.5wt% sodium chloride, inside the tube, forming a corrosion cell. The bottom tube opening is sealed with nickel alloy/ titanium alloy plug welds, while the top is connected to condenser attachments. To ensure no loss of corrosive vapours during heating, PTFE/ acid resistant tape is used for sealing. A trap atop the condenser tube allows for replenishing corrosive liquids during long tests. This innovative and relatively simple apparatus, with precise temperature control within ±5°C and insulation, provides an effective means to test for stress corrosion cracking qualitatively, enhancing the safety and reliability of power plants.
Disclaimer: Curated by HT Syndication.
