Key points of installation technology for metal ring gaskets used on the RJ sealing surface of pipe flanges
Thread Content
In hydrocracking and hydrofining units, RJ sealing surfaces are widely used for pipeline flanges, with metal ring gaskets being used as the corresponding gaskets. The proper or improper installation of metal gasket rings on these high-pressure pipe flanges can significantly affect the overall maintenance of the equipment as well as the schedule for bringing it back into operation. Therefore, special attention must be paid to the installation of gaskets during the construction of such flanges. So, what are the things to pay attention to when installing metal ring gaskets? Are there any key installation techniques or methods for such gaskets? Thank you!
The sealing surface must be cleaned thoroughly; iron shavings are the worst thing for metal gaskets, as grooves can lead to leaks.
Ensure that the groove and metal gasket are in good condition, free from any defects such as scratches that could affect the sealing performance
Section 6.2.3 of SH 3501-2011 \"Code for Construction and Acceptance of Steel Piping Projects for Toxic and Flammable Media in the Petrochemical Industry\" states that before assembling flange connections sealed with metal ring gaskets or lens gaskets, it is necessary to check whether the sealing surfaces of the flange grooves (or pipe end faces) are in contact with the metal ring gaskets or lens gaskets. After rotating the metal ring gasket or lens gasket 45 degrees on the sealing surface, check that there are no interruptions in the contact line; otherwise, grinding should be performed. “ This mentions the \"contact wire\" – does it mean that only one inspection of the contact wire is needed? Or do all the contact sealing surfaces need to be inspected? Additionally, when inspecting the contact wire, a red substance is applied to the sealing surface to facilitate observation and verification; once the contact wire emerges, it becomes very visible. These are all experiences shared by others; I haven’t carried out the work myself, so I’m still worried that problems might arise. The paraffin oil hydrogenation unit is about to be shut down for maintenance, and flanges of model CL2500 need to be removed and installed on components such as the thermal high-pressure separator and reactors.
As the original poster said, regular construction teams, when installing the flanges on the RJ side, will carry out inspections of the sealing surfaces (using the red lead test), and the SY handover technical documents require that relevant records be kept
That’s what they say, but on site I hardly saw any construction company following the regulations. It’s all about placing the gasket and then using a hammer and wrench to tighten it.
It’s that the construction party didn’t realize they could hold a quality meeting to make such requests.
Our company has a \"Management Procedure for the Disassembly and Assembly of Critical Flanges.\" Whenever a flange meets the criteria for being considered a \"critical flange,\" it must be tightened using hydraulic wrenches or bolt stretchers.
There is a supervisor, but that supervisor is essentially ineffective; often, the supervisor is unaware of the problems raised by the owner, or even if they are aware of them, they say nothing about it, so that the owner remains uninformed. We don’t have enough staff; there is only one quality management officer for the owner, and it’s impossible for that person to handle everything.
Was it installed by that installation company? ? ?
We don’t have any specialized tools or programs either. It means that the surfaces of the flange and gasket sealing surfaces must be cleaned thoroughly, with a smooth appearance when viewed visually. The installation quality mainly depends on the pressure testing for leaks. I’ve learned it.*