Replace stainless steel 316 pipe

[Nad87]

hello,
there is too much leakage in our ss pipe we tried to weld many times but not succeed also stain less steel 316 is not available now in the market because of this pandemic
that is why am trying to know which type of material we can put in place of stainless steel pipe?
we have RO plant to produce drinking water and the pressure is about 10 bar.

 

[EdStainless]

All of the pipe mills that I know of are still running, there should be plenty of 316L pipe out there.
Whoever is telling you that is saying that they don't want to bother getting it.
You don't have a lot of options. You don't want less corrosion resistance so the next step up would be 317L (strictly custom) or 2205 duplex. The 2205 would work and likely you could go lighter wall, but the welding would be a pain.
Actually a lean duplex would be easier (LDX2101 or 2202 or similar) but those are not very common in many places yet. Eventually they will replace 316 in nearly all applications between -40C and 300C.

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P.E. Metallurgy

 

[0707]

Your water shall have less than 50 p.p.m o chlorides! But as EdS said there should be plenty of 316L pipe out there.

luis

 

[Dhurjati Sen]

What are the materials do you have presently at hand? As a stop gap arrangement, you can replace 316 with any 300 series SS.

DHURJATI SEN
Kolkata, India

 

[LittleInch]

FRP?

PE?

What do you mean by "too much leakage"?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Nad87]

Thanks all for replying

@EdS yes that is true the ss 316 is the best material to treat high pressure and avoid corrosion problem.
@Dhurjati yes am trying to find even 304 but still not available because of block of some areas means we don't have many choices because of this pandemic.
@LittleInch the material is stainless steel and too much leakage means not drops it is continues lines and in many areas elbows tee ...

Thank you very much again.

 

[mk3223]

Was the root cause discovered for the water leak of the 316SS pipe for the RO service?
It can be difficult to select another high alloy material without knowing the real cause.
Also, other than 316SS pipe, what other alloy pipe are available in your area?

 

[thebard3]

If your pipe is failing in the weld heat affected zones then it's probably not related to the alloy at all, but rather a faulty welding procedure. If that's the case, then cutting out and replacing bad sections is probably going to be a continuous and on-going repair effort. Otherwise, there's something about the RO water that should be compatible with 316 SS. Perhaps (credit to 0707) too high chlorine concentration.

Brad Waybright

It's all okay as long as it's okay.

 

[georgeverghese]

Possible material options are : FRP, GRE, SS316L (with at least 3.5-4% Mo), 6Mo stainless steel, standard duplex stainless (2205 duplex). Looks like you have a tougher job of justifying a plant shutdown to get these leaky joints replaced.

 

[EdStainless]

George, 316 is 2-3% Mo, the high alloy version is 2.5% min Mo.

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P.E. Metallurgy

 

[georgeverghese]

Ed, General talk I've heard from materials engineers is that the older versions of 316L had higher Mo (at least 3% I recollect) compared with the corrosion prone lower Mo content grades in the market these days. Believe N content also some significant part in corrosion resistance. In any case, would guess SS316L is a poorer choice in this application.
If none of these grades listed are within reach, see if you can get marine grade 90:10 copper nickel fittings for short term relief - Specialist welders required for this, same for 22Cr duplex.