FRP Storage Tank

Plastics might be a better choice. There are fittings called "tank adapters" that are sealed to the tank wall with gaskets, and have sockets or threads that match standard pipe sizes. E.g.

basically sir, i have doubt regarding use of metallic flanges for FRP tank. because i saw flanges of polypropylene. & also use of stubend

This agrees with post 1, which suggests plastics as possibly a better choice. Most of the "tank adapters" I mentioned are plastics of various types (PVC, PE, PP, Kynar, FRP, etc.), with various elastomer gaskets.

Most manufacturers of such plastic products have corrosion charts that will allow you to select a material suitable for HCl service. Off the top of my head, I don't know which is best. In addition to corrosion resistance, you must also consider strength if the pressure is high.

Agree. ... select a material suitable for HCl service ...

For any chemical service, consult material compatability databases to check the suitability of any material (metals, plastics, rubbers, ..., anything). Also, don't simply rely on one source - check multiple incase one isn't correct.

I can recommend Cole Parmer Chemical Compatability Database http://www.coleparmer.com/techinfo/chemcomp.asp

Note: as well as strength, need to also consider operating temperature/pressure considerations.

Hope this helps.

Anthony

Maybe I'm missing something in translation here, but FRP tanks for HCL storage typically are hand layup bis-a epoxy vinyl ester construction, and so are all of the associated penetrations through the shell - you may choose to bolt up piping of a different construction (e.g. PVDF or PP, rubber lined steel...), but anything that's going to penetrate the shell should be FRP, and the FRP/FRP joint is critical, as these connections are often the first to have problems in the long run.

Flanges should be the same material as the tank. You will not have a good bond between metallic flange and fiberglass tank, it will leak eventually.

Is this an ASME RTP-1 tank? If so the outlets / nozzles are restricted by the standard.

It sounds like you are descibing a Van Stone flange, a loose hub of metal that holds the FRP faces together. They make a good bolted connection.

Nozzles with integral hubs made entirely of FRP are another option and are also a godd bolted connectionThe attachment of the pipe end of the flanged connection to the tank is by hand layup along with whatever reinforcing pad is required to account for the tank structure removed by cutting the hole.

Either way there is usually a requirement for the nozzle to be reinforced using gussets of some fashion to withstand a vertical load due to pipe weight or being stood on.