NACE MR 0103

[Lahane]

One of my project requirement was to build a CS spool.NACE MR 0103 was involved in the specification

I already build a spool which has got a supporting PQR without pwht.As per NACE MR 0103, welding of p1 materials needs to be done as per RP0472.Road map of RP 0472 gives 3 options.one is pwht, second is chemistry control of base metal & last is HAZ hardness control in PQR as per sec 5.

Unfortunately, I have not follwed the first two option.
The last option says that practices to be followed in sec 5 should be specified by customer, but customer spec does not have such information.

What needs to be done to come out of this situation to comply with NACE requirement?

 

[vesselfab]

well if it were me, i would weld up another coupon and pwht it to support another wps.

our shop has for every wps, a duplicate with a different id number qualified with pwht just for such an occasion.

you could ask your customer, but he will have assumed you knew what you were doing and tell you to start over.

 

[jrupert24]

Best thing to do is have your welder make you a mock up pipe weld using the same process, weld wire and pipe material as you made in production. Send it out to a lab (or do it yourself if you can) and have it polished and a hardness surveyed per RP0472 which is fairly lenient vs the new SP0472.

If the pipe spool was A106 gr B, most likely you will pass if you were using an A1 chemistry weld wire. I just tested a few different thicknesses and I passed them without an issue. Can't speak for other materials.

Anyway, this is the best way for you to find out what you actually have in production. Once you know what you have, you then can decide if you need to PWHT or some other method to bring the hardness down. I don't see another way for you to demonstrate your materials, process and weld wire meet MR0103/SP0472 other than the mockup at this point.

Let us know how it goes.

 

[jrupert24]

BTW, what is the pipe material, welding process and weld wire you used?

 

[Lahane]

pipe spool material is A106 gr B/A105.
Process: GTAW+SMAW
Wire:ER 70S2& E7018-1
I already welded a test piece using same wps & in lab for hardness as per Fig 2 of RP 0472.but customer is not accepting it by saying it does not meet sec 5 of RP0472.

 

[jrupert24]

I would have a lot of fun with this one and the client!! They are being way too picky. Do you have a copy of RP0472? Hopefully you do. You can't get any better than welding up a test piece from actual materials used in production. In fact, you don't even have to do that per RP0472 5.2 "materials and welding conditions used for procedure qualifications tests SHOULD BE equivalent to what is used for the equipment and piping". You could have presented them with something "equivalent" instead of actual.

I would ask them which section specifically you are not meeting so you can address the specific issue they are having a problem with. Seciton 5.1 says "The user shall specify when this hardness testing is required and which of the following practices are required after reviewing the intended service for the weldment". If they did not specifically address which are required, I think you have some room to flex. Also, look at seciton 5.7 which states "user MAY require that both forms (PQR and hardness survey) be submitted for approval prior to production welding". Obviously they did not require you to submit before hand which may be another point to argue.

The only issues that I think could be valid is that your coupon could have been welded on a heat with a lower CE than your other heats. I would go back and check all the heats and make sure you weld on the one with the highest CE. Also, just because you did not order your pipe "chemistry controlled" does not mean that you do not meet the criterial for it. Read through Section 4 and get your hands on 8X194. I think you will find that A105 gr B would be simple to meet the requirements. The other issue they might throw at you would be 5.2.4 which gives you a +25/-10% variation in heat input. If your welder did not know he could only go below the max heat input by 10%, it is posible to argue that there could be hard spots not represented by your coupon. In that case, I would weld a coupon with the lowest heat input a welder might use an retest. (remember the user has to specify which practices are required) Most of them don't know the code very well.

Its too bad that your client is being stubborn with working out the situation. Personally, I prefer production representative hardness surveys over the "equivalent" that is allowed by the code.

Let me know how it goes. I think you have a leg to stand on.