Do u need to pre-heat weld rods for seat rings?

[Gorman3]

Do seat ring welding rods need to be pre-heated? I've been told that they do not. The supplier we use preheats the overlay rods but they told me that seat ring rods are always the same material which I believe is copper.

We are preparing for an API 600 monogram and I am not sure what this procedure should be.

thx for help,

Nick

 

[UNSR60001]

valvebot:

your question is so generic that I will in turn answer you in a generic way.

It is good practice to always preheat welding rods. When it comes to making a decision to preheat or not to preheat welding rods the answer is "when in doubt preheat"

Now to really address your question. It is the responsibility of the manufacturer to develop QA/QC procedures that translate into meeting any set standard that you put as the goal, such as API or ISO ect.

The welding procedures that you will or have to use in order to comply with a standard, are particular to your manufacturing facility. The reason is that when it comes to welding there are so many variables that affect the outcome that only you can develop the procedures that will allow you to meet the set standard.

Equipment, welding method,Rod or wire or powder quality, Base material, overlay material, ambient temperature, humidity and base material temperature. All of this this factors could or would affect the overly outcome. Only you can know this conditions thereby developing your own procedures.

Good luck

 

[11echo]

Just for my own peace of mine here, what you call "seat ring welding rods" ...do you mean "chill ring" ...a ring with lugs on it that is inserted into the pipe at a weld site? To control weld gap and slag forming on the inside of the pipe?

 

[Gorman3]

No I mean the actual welding material that is used. It is usually copper and it welds a Stellite Ring onto a WCB Body.

What is a chill rod? Can it be used in the process I described above?

 

[caihui]

if per QA the welding rod should preheated and then put them in a heat preservation case before welding. But now alwasy use PLASMA. Maybe you should reference the PLASMA manual. Hoping it's helpful.

 

[Gorman3]

Apologies for my ignorance as to welding. But what do you mean by plasma?

 

[caihui]

plasma is auto welding machine.