How do you inspect a flange?
How do you inspect a flange?
To inspect the raised flange face area, encoded magnetic scanners direct sound from the OD of the flange between the bolt holes. With PAUT one can engineer the ultrasound angles to fit the specific flange geometry.
Why should you inspect the flange?
The MISTRAS flange face inspection technique examines the entire width of the flange raised face (sealing surface) and has the ability to determine corrosion presence, maximum material loss in terms of depth and any progression of existing corrosion across the sealing surface.
Do flanges need gaskets?
ASME B31. 1 says that when connecting flat face cast iron flanges to carbon steel flanges, the raised face on the carbon steel flange must be removed, and that a full face gasket is required.
What is flange surface finish?
The flange face surface is the area where the sealing element (gasket) is installed. The most common flange face surface designs are smooth and serrated. Flat face (FF) flange surfaces and raised face (RF) flange surfaces require serrations if built to industry standards.
What is ASME pcc1?
ASME PCC-1, Guidelines for Pressure Boundary Bolted Flange Joint Assembly (BFJA), is a standard created and published by the American Society of Mechanical Engineers (ASME). This standard gives directions for the training and qualification of bolted joint assembly personnel.
What is the difference between a flange and a gasket?
Gaskets seal a connection between two components or flanges that have flat surfaces, while seals are used between engine parts, pumps, and shafts that rotate. Gaskets are used wherever a union or flange is required to prevent leaking. Gaskets are most commonly used as static seals.
What is the purpose of a flange gasket?
Flange gaskets are designed to seal the space between two sections of pipe. Most pipes, of course, are joined at a flanged surface. The surface where two pipes join isn’t smooth or otherwise flat. Rather, it’s flanged, meaning it flares out.
What is flange serration?
The flange face has small grooves as you can see in the image. This machining is known as a serration. Flange face can be smooth or serrated type. Soft material of gaskets is set in this serration and prevent liquid or gas from passing from flange joint.
What should the roughness be on a gasket flange?
The ASME B16.5 code requires that the flange face (raised face and flat face) has a specific roughness to ensure that this surface be compatible with the gasket and provide a high quality seal. A serrated finish, either concentric or spiral, is required with 30 to 55 grooves per inch and a resultant roughness between 125 and 500 micro inches.
What are the inspection criteria for a flange face?
Appendix D includes figures and tables that provide guidelines for setting allowable limits on flange face defects. Specifically, it shows how to assess damaged portions of a flange face by taking measurements of the defective areas (see Figure 1 in Appendix to Article – Flange Face Inspection Criteria ).
Why do you need a full face gasket on a cast iron flange?
ASME B31.1 says that when connecting flat face cast iron flanges to carbon steel flanges, the raised face on the carbon steel flange must be removed, and that a full face gasket is required. This is to keep the thin, bittle cast iron flange from being sprung into the gap caused by the raised face of the carbon steel flange.
Are there any problems with resurfaced flange gasket seating?
However, I ran App 2, and it passed if not considering additional 1/8″ corrosion allowance in the flange thickness, and only 200 psi overstresed in seating condition if considering additional 1/8″ corrosion allowance in the thickness. Any problem of resurfacing ? Please let us know here why this post is inappropriate.