Japanese black lacquer

[yyulius77]

Hi All,

We're working on a project where there is a diesel line feeding into gas turbines, carbon steel A106B piping system. The diesel vendor supplied us with pipe & fittings with black internal coating, which people call Japanese Black, or Black Lacquer, or whatever it is. The pipe was rejected by our client. We have since aquamill it to clean it, and we want the vendor to pay for it.

To be honest, we have never heard of this black thing before, and we didn't specify anything in our Spec about having to remove this.

Talking to some older guys, they said this used to be common in the old days, but they never thought they still exist today as they create of problem. So they think it is an industry standard to remove it prior to using. The vendor should've known, in their opinion.

And we are trying to argue the case against the vendor, why did they supply pipe & fittings with this internal coating? Why didn't they remove it before shipping to site? They argued, "You guys didn't specify removal of it in your spec. You only specified pickling, and we did pickle." We argue, "We don't have to specify, you should have known, as this is an industry standard."

In your views, ladies and gentlemen, who is at fault? Should have we specified it? Or should have they known to remove without us having to tell them?

Any standard or code that you can reference about having to remove this thing prior to use? Is it okay to leave it in for GT diesel?

Cheers,
YY

 

[Duwe6]

Definitely not "Industry Standard". But there might be diesel-feed-to-turbine problems. Or not.
It is standard and necessary to preserve c/s pipe unless rust is acceptable.

If the customer didn't put it in the spec, you didn't owe it to them. But the cleanliness may have been an obscure mention in that spec.

 

[1gibson]

Before you determine who is at fault, you need to determine if any mistakes were even made. "Client doesn't like it" doesn't always mean it can be rejected per the contract. If the material was per the contract, then the only person at fault is whoever allowed the client to reject it. Sure the client can do whatever they want, reject it even if it meets the contract, but that is when you discuss costs for complying with the new requirements.

A106 has some supplementary requirements (only applicable if specified in PO) and one of them is internal cleanliness. Too late to help you now, but maybe in the future.

 

[LittleInch]

The key question is "what was it" and does it have a impact on the quality of the diesel fuel?

To reject it out of hand without going through this step is wrong and will land the client with a bill for removing something that didn't need to be removed in all probability. If you can show that the internal lining , given the fuel you were transporting, would injure the fuel quality or the turbine, then you have a right to reject the pipe and make the supplier give you something that didn't affect the fuel quality.

On the other hand, the supplier should have been a little more open in their bid or documentation that the pipe they were offering you was lined. Maybe they did and you didn't pick it up?? It seems a bit odd they did this without telling you or apparently without it being specified, but maybe they had a load left over form the last job??

I'm with the supplier here unless you can prove that the lining would impact fuel quality, but sounds like it would improve it to me and prevent rust and corrosion before you fill it with diesel. If they pickled it and it still didn't come off it must be pretty good stuff.

Have you just cleaned it or removed it?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[yyulius77]

Thanks for your feedback guys.

By the way this internal lining is normally known as "Japanese Black Lacquer". Yes, they prevent corrosion, but my understanding it is a usual practice to remove by abrasive cleaning prior to use. Pickling removes metal rust, etc., but it doesn't remove this stuff. I found an article here

http://www.vecom.nl/english/documentation/tb/VecomTechnicalBulletin-2008-02-ENG.pdf.

I think they just forgot to do it, because for other pipes they supplied, we don't find any of it.

Our client didn't specify anything to us. We didn't specify anything to our vendor about having to remove this coating (we can't specify something we don't know/expect). What we specified were A106B pipe and pickling (we failed to specify the fittings material). When I looked at the MDR, they might have supplied API 5L Gr B.

Good advice to ask the turbine supplier what effects it may cause to the turbine. Since this is a polymer type stuff, perhaps diesel will dissolve it and the stuff will get burned in the turbine without anybody knowing.

Site Mgr decided to remove the lacquer altogether with aquamilling. This coating can only be removed with abrasive method. It was just costly to do it on site.

The way things are going, I believe we will just absorb this cost. But I need to learn for the next project how to prevent this from happening again. So if you guys have any spec, code, etc. about this issue, it would be very helpful. Thank you.

Cheers, YY

 

[LittleInch]

You could say in future, "no internal lining to be applied", and "any internal coating or preservative to be removed prior to installation", or something similar.

I'm still a little surprised you're removing this stuff, from the limited amount of info I could find it looks like a fairly stable material. I still suspect the supplier just had some left over from another job or got it cheap....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Compositepro]

I've not heard of this coating but it is certainly beneficial for preserving the pipe prior to installation and it maybe beneficial or harmful after installation. However, one thing that is clear is that you cannot pickle coated pipe. Only clean bare metal surfaces can be pickled.