Welding on SA 266 gr 2 1

[rmw]

Yes, I have looked in most of my reference material, and will continue to do so, and yes, I have googled it.

Having said that, and still coming up empty handed, can someone tell me about, or refer me to where I can find out about this carbon steel material.

My interest is on welding issues, and my application is a 50 year old utility HP feedwater heater channel body and nozzle(s). This heater is dead, (beyond repair) and we are considering welding a plug in the inlet/outlet nozzles until (1) the rest of the plant around it dies as well, or (2) it is replaced (which is not going to happen).

The nozzle thickness is 1-3/4" or 45mm. Design pressure is 3450 PSIG, and determining the thickness of the plug required is not a problem.

rmw

 

[unclesyd]

Just to get you started it is classified as a carbon steel forging material with a minimum tensile of 70,000 #/in^2. It is also a P1 material. ASME 1965

I have some other data and will try to find it and if I remember correctly we used to weld on it.

 

[metengr]

RMW;
Have you looked at removing a small material sample for chemical analysis or better yet, using a portable alloy analyzer to type the material? Working for a utility, this is common on some of our older fossil units!

Once you type the material, you know what you are dealing with in terms of welding information.

 

[rmw]

Metengr,

No, the heater is not worth all that expense, nor is there time. The outage is only a few more weeks in duration, and I have to make a recommendation to the project engineer stat.

Unclesyd, I suspected it was a P1 mateiral, but wanted to make sure there was not chrome/moly of any kind to have to deal with. As you know, that would dictate PWHT, and other things that we need to deal with.

The nozzle and the channel are both SA 266 gr 2, and are of welded construction. The heater spec sheet verifies the 70K min TS, but does not indicate anything other than welded construction.

Need to verify the P1.

I suspect this is a case of an older material superceeded by a currently used material, (something like A350 LF2) but I can't cross it over, and we have to do something with this boat anchor soon.

Thanks for helping.

rmw

 

[unclesyd]

Someone out there has an index of ASTM standards that should cross reference the standard.
According to the code book I have it is a P1 material. Also I have two old welding electrode handbooks that also call it a P1 material neither have a welding spec for it.
One calls for E7018 and the other E8018.

I'm still looking for other information.

I have a reference of SA266 to UNS K03506 and it is a C-Si steel.
It has a references to being covered under Sec IX QW-422 and non-nuclear code case 1876
It is P1 Gr 2.
It also references SA541 Cl 1 for Gr1 but doesn't appear to reference Gr2, but lumps SA266 Gr1&2 togather.

 

[sayee1]

SA266Cl2: P1 Gr No 2, easily weldable, can be welded with the 70 ksi consumables(E7016/E7018/ER70Sx)You can find the material specifications in ASME Section IIA.

Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668
email: sayee_prasad@yahoo.com
If it moves, train it...if it doesn't move, calibrate it...if it isn't written down, it never happened!

 

[rmw]

sayeeprasadr,

So, I assume there is no pre heat, nor post weld heat treat required as a P1, even at those thicknesses, since you did not address it??

That is really all I am concerned about.

rmw

 

[sayee1]

Need more information on the weld joint design and the code of fab, but typically assuming ASME Section VIII Div 1, PWHT would be required if the nominal weld thickness exceeds 31.8 mm, unless of course preheat maintained as specified in UCS 56, in which case PWHT would be required if the nominal weld thickness exceeds 38.1 mm. In this case what is the nominal weld thickness? Also assuming 45 mm nozzle thickness, you would require to preheat in any case, and typically I would preheat to 100-150 Degrees C. Again what is the material for the plug?
The thicknesses and Section VIII clause reference is from my memory and needs verification. I'll be able to provide the details after you provide the same.

Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668
email: sayee_prasad@yahoo.com
If it moves, train it...if it doesn't move, calibrate it...if it isn't written down, it never happened!

 

[rmw]

sayeeprasadr,

The vessel is a "U" stamped vessel, what ever section VIII that was (I did unfired vessels many moons ago, and have slept way too many times since then to remember all the Div. numbers, that is why I am picking the brains of the guys like yourself who live in that world.)

It is a vertical, channel down, full access design, heat exchanger so access to do this type of welding is not prohibitive.

The plug material, thickness, and hence, the weld joint design, taper, or whatever, have not been determined yet, although this is a common method for making a FWH mansafe for working inside of, especially on Hemi head designs, when the heater has to be worked in while the unit is returned to service, so the doing of the design is not hard, and commonly done, for someone above my rank.

Some of that decision will hinge on determining what is this SA-266 that we are welding the proposed plug to.

What we are trying to determine right now, is, what are our options, and what are the hurdles. One is plugging the inlet/outlet nozzles (forever) and I am trying to ascertain the ramifications of that process but am stymied by an unfamiliar metalurgy.

Other things are being looked at by the project engineer I am trying to assist, such as plating over the entire tubesheet, which gets a thumbs down from me, and cutting the FW lines away from the heater, and capping them, likewise problematic at that size and pressure (and space limitations.)

If someone can just say, SA-266 gr 2 is the 1950's version of the current SA-XXX gr XX, then I can launch. Nothing I had in my reference material would do that for me, and that is my basic request, along with anything else that someone would wish to inject into the discussion.

Thanks for your help in the matter.

rmw

 

[metengr]

rmw;
We had several HP FW heaters some time ago that we retired by cutting and capping the feedwater inlet and outlet piping, and steam inlet and drains. We wanted to completely isolate the heaters because they were junk, and posed a risk of failure. The cutting and capping of the piping posed no problems,it was done by field machining (cutting and prepping in one step), and welding of the pipe caps was performed using ASME Section VIII, Div 1 UCS-56 requirements.

According to the ASME B&PV code 2001 Edition, 2003 Addendum, SA 266 Class 2 is still in effect other than Class 2 is now called Grade 2 per the specification, and is a C-Si forging (0.3% max C, 0.4-1.05% Mn,0.025% P and S, .15-.35% Si). This is a P1 Group 2 material.

 

[rmw]

metengr,

Thanks for the technical info. That will get us launched. The subject came up yesterday on Friday, and more and more, utility people and their suppliers are becoming 4 days of work per week people, with Fridays off. It is like a ghost land out there, when you need someone to call on Friday, hence my thought that Eng-tips could produce some answers.

The pipe cap idea is still on the table, but with the unit due back on the line in less than 3 weeks, some of which time is consumed with things like hydro, and chemical cleaning, the ramifications of which are not clear with respect to the ability of the heater to be completely isolated due to the leaking isolation valves, (the reason it can't just be bypassed) the plug idea is favored.

Immediate availability of such a cap in that time frame is also in question, while the plug will be cut from plate.

We will probably just cut and cap the extraction steam and drips inlets, and the condensate outlet. They aren't as large, nor thick.

One other thing you might want to be aware of is that this heater is located up on the boiler steel, yes, at the 6 th level, counting elevator stops, and a certain amount of "sky hook" usage would have to be done to get complete access to the piping to do capping. It is the only unit in a several state area that I am aware of that has the HP heaters up on the boiler.

All the input is appreciated.