[00700]

Need help to choose excellent resistant material for meduim containg Cl compositions.
Trying to get correct body material for gate valves with following operational medium:
1. gas (Cl2 – 0.026 (max up to 2.4 g/m3) , NaClO – up to 3.1 g/m3
2. gas (Cl2 – 1.2 (max up to 110 g/m3), HCl 1.43 g/m3, (MgCl2, KCl, NaCl) – 2.27 g/m3, size of particles: not exceed 100 μm
3. gas (Cl2 – 0.026 (max up to 2.4 g/m3) g/m3 , NaClO – up to 3.1 g/m3
4. powder including gas Cl2 – 94%, (KCl – 61%, NaCl – 21%, MgCl2 – 13.7%); size of particles min. 1 mm

[marquis]

We used stainless steel for industrial chlorination.  I don't remember the exact alloy.

[408]

That mix is not something that is nice to metals.  Especially with the hypochlorite in there.  You will want to be looking at very resistant metals, similar to what is used industrially for the production of  chlorate by electrolysis.  Titanium would work

Some others listed here: http://www.wfvisser.dds.nl/EN/chlorate_EN.html#el_body

[00700]

Titanium is the first thing i thought about. It can be too expensive.
Any alloys?

[arthurzhuo]

Need help to choose excellent resistant material for meduim containg Cl compositions.
Trying to get correct body material for gate valves with following operational medium:
1. gas (Cl2 – 0.026 (max up to 2.4 g/m3) , NaClO – up to 3.1 g/m3
2. gas (Cl2 – 1.2 (max up to 110 g/m3), HCl 1.43 g/m3, (MgCl2, KCl, NaCl) – 2.27 g/m3, size of particles: not exceed 100 μm
3. gas (Cl2 – 0.026 (max up to 2.4 g/m3) g/m3 , NaClO – up to 3.1 g/m3
4. powder including gas Cl2 – 94%, (KCl – 61%, NaCl – 21%, MgCl2 – 13.7%); size of particles min. 1 mm

Use FUV strcuture ceramic-lined ceramic valves,that can solve your problem.

[Enthalpy]

The chemicals you mention look like an easy task for good stainless steel.

Usual marine grade (17% Ni, 12% Cr, Mo, sometimes Ti, low C) should be enough. Mo and Ti give resistance against Cl, which would otherwise corrode common stainless steel. You may prefer grades developed for chemistry (36% Cr, 18% Ni for instance). No need for titanium. Beware titanium may catch fire: this can be a risk in chlorine.

Duplex stainless may be cheaper, harder, and good as well, but I didn't check.

In all cases, your answer is long known from steel providers. They publish huge "compatibility lists" with alloys versus chemicals. Goodfellow, steel producers...

You might have a look at surface coatings like Ni or Ti3N4.

Beware stainless steel as well as titanium alloys are very prone to seizure, which may be a worry for a valve. Dissimilar running materials do NOT help. Cr coating is bad, Ni is good.

Will NaClO decompose a bit in contact with such surfaces? Maybe acceptable in this use?