Brine Service

[mitenpatel]

Hello,

For Brine Service application, our spec indicate to use monel N04400 materials for NPS smaller than 2". However, drain and vent valves for Monel 400 materials are way to expensive. Other alternative is to internally coast CS valves, but it's really hard to interally coat smaller valves than 2". Is there any other alternative for this application?

Thank you,
Miten

 

[EdStainless]

How strong of brine? 2x seawater?
What temperature?
There are other Ni alloys that you could use (C276) that may be more available, but they won't cost less.
There are plenty of cheaper options that won't work.

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P.E. Metallurgy, Plymouth Tube

 

[mitenpatel]

Thank you Mr. Edstainless for your reply.

The assumption was made to have Chloride concentration : 10%, Temperature: 35 C, pH level: 8, oxygen concentration: 15 ppmw. However, it was found later that chloride concentration will be even less.

We are trying to find alternative for smaller valves (1/2 - 1 1/2) which will be used for drain or vent valves, and does not require to be as expensive as monel valves. They are such small size that internally coating is not feasible.

Thank you,
Miten

 

[EdStainless]

In a valve where there is no flow the fluid will sit stagnate and corrosion will be more severe.
This is especially the case at the seal surface itself.
Follow what others have learned the hard way, use the correct metallurgy.

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P.E. Metallurgy, Plymouth Tube

 

[nickypaliwal]

Fully agree with above comment regarding corrosion. Although Super-duplex SS is expected to have corrosion issues however our client has been using SDSS for a few years now (for brackish/seawater) since the failure or leakage of water line, even if caused, would not be critical to safety. We have been using it for temp up to 42 degC and your case is still with lower temperature.

 

[EdStainless]

Given the difficulty of machining superaustenitic and superduplex alloys I would just go with a Ni alloy and be done with it.
Use C276 with PEEK seats and then don't worry about the valves, ever.

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P.E. Metallurgy, Plymouth Tube