Alky plant - gaskets

[mel124]

Hello everybody.

what kind of gaskets are you installing in the piping connections in an Alkylation plant ?

Thanks

 

[flexibox]

Assuming this is a HF Alkylation plant, and if my memory serves me right there are special spiral wound gaskets that change color on the outer if there is a leak indicating that there needs to be a change. Perhaps someone can confirm this.

 

[bk19702]

HF or Sulfuric Acid?

Don't know about the gaskets changing color, but the paint on the flanges does (from yellow to red) upon contact with HF. Most gasket material will be a Monel spiral wound type or similar in these applications.

 

[gasketguru]

I think this depends on whether your process is a UOP or Phillips licence. Usually either graphite or PTFE filled spirals with Monel windings on HF alky plant. Guide rings (inner/outer) are either C.S or Monel depending on the piping spec. Some people also now prefer to make the inner rings into kammprofile type gaskets on CS piping, with graphite layers etc., as a kind of double-gasket system to prevent corrosion in the dead-space area around the inner ring.

As mentioned above the detecting paint is usually applied to the outer ring to readily show when leakage has occurred.