Hasmid If your vessel is designed earlier to whatever code period in which it was fabricated, the HT pressure test should be strictly as per applicable code design & year in which it was fabricated then. i.e, the HT test pressure should be govered by the design code practice of the year of fabrication. If your vessel is fabricated to latest code design & year, then the current HT pressure is applicable as per current code fabrication and material used. If the vessel is de-rated, by chance, due to whatever condition from corrosion assessment and the likely de-rating done, then you can do HT at lower than design pressure x test pressure applicable to meet design code test conditions. Trust this helps you C.V.Srinivasan Nishi Engineers Pvt Ltd India Oct 11,2006 E-mail: nishi@vsnl.com >I think the latest applicable code for HT pressure is 1.3 >times of the design pressure. > >Please advice.