How is the roughness of the flange face measured?

Now the measurement value of Serration of flange face is specified in RMS (Root Mean Square) or AARH (Arithmetic Average Rough Height). These two are the units used to measure the roughness of the flange face.

Why are the faces of two RTJ flanges different?

The faces of the two opposing flange faces do not come into direct contact with each other, because a gap is maintained by the presence of the gasket. Such RTJ flanges normally have raised faces, but flat faces may also be used or specified.

Why are the grooves on the flange face important?

Contact between the flange faces enables gasket compression and plastic deformation to be controlled. As both the ID and OD of the gasket may contact the grooves, holes are normally drilled through the gasket to ensure pressure either side of the joint is balanced.

Which is the best type of flange face?

Flange faces can be a smooth or serrated type. Which type of face to use, it depends on the type of the gasket and service of the fluid. The flange face with small grooves as you can see in the image, this machining is known as a serration.

Why are my flanges not flat on the face?

This can occur because of excessive loads on the flange or as the result of errant machining of the flange surface. Soft gaskets will also tend to conform to and seal areas of poor flatness better than a hard gasket. Again, the tolerance of a lack of flatness depends on whether the gasket is soft or hard.

What kind of damage can you get on a flange?

Scratches —This type damage is narrow and elongated with sharp, shallow bottoms. However, depending on the force that created them, they can be deep. Frequently, this type damage is created by a sharp object dragging across the flange face. These objects may include the bristles of a wire brush or a tool, such as a chisel.

Can a soft gasket cause flange damage?

A lack of flange flatness can also be considered damage. This can occur because of excessive loads on the flange or as the result of errant machining of the flange surface. Soft gaskets will also tend to conform to and seal areas of poor flatness better than a hard gasket.

What should I do if my toilet flange is too high?

If you’ve already laid your flooring, and the toilet flange is too high or unlevel, there are a few things you can do. First, you can pack grout into the gap between the floor and the flange. Give the grout 24-hours to dry and sand down the rough edges. Second, you can raise your floor by laying down thicker tile.