Gentlemen, We've used qualified welding procedure specifications for LTCS that specifiy a root layer of 6010 (but only 1 root layer and no hot-pass) and then fill and cap layers with 7018. This welding was performed on pressure piping under B31.3 for use in Northern Canada (min. design temp. of -46C). The WPS was qualified, stamped by professional welding engineers and approved by the client. It is my understanding that the root lay is limited in thickness on the WPS and therefore the total thickness and properties of the full weld are majority 7018, which is approved for LTCS. The heat input is limited to a max. on the WPS so that the welded joint should have the adequate impact properties at low temperatures. This will be proven during qualification but remember not to limit yourself on heat input on the WPS, use a typical heat input for your welding process and material thickness to pass the qualification. Regards, JZ --- On Mon, 9/28/09, Muhammed Ibrahim <ibratech@gmail.com> wrote:
|
Materials selection, welding, forming, Heat treatment, corrossion, NDT
Comments