Recent content by GordonF

Hi We are looking at the requirement to use antistatic utility air hoses in offshore applications, typically 1/2 and 3/4 inch air hoses at 1MPa. Our internal standards call for antistatic hoses but the antistatic requirement is being challenged. The literature read so far does not...

Dear All We have a number of utility boilers of varying ages and are in the process of rationalising boiler tube stocks. I would like your opinions on the most commonly used boiler tube standards. The ones we are currently considering are: ASTM standards (A192,A209,A213) ISO standards...

I am interested as well. Has this progressed?

Hi We have experimented with various materials for valve spindles operating in steam at 540C including Nitrided low allow steels (EN41B) Nitrided 12Cr steels Incolloy 800 HT The most successful valve spindles have been a low alloy steel (AISI P20) coated with Stellite 6. We wish to...

We have experimented with various materials for valve spindles operating in steam at 540C including Nitrided low allow steels (EN41B) Nitrided 12Cr steels Incolloy 800 HT The most successful valve spindles have been a low alloy steel (AISI P20) coated with Stellite 6. We wish to manufacture...

Thanks again for all the replies. Boo1, the idea for the partial weld repair did come from looking at the fundamental equation for K. As you have written, in general terms (ignoring geometry factors) K=ó*(Pi*a)sqrt If you look at the formulae for K for an embedded crack...

Thanks for the replies and a few comments. The equipment is operating in the creep range and therefore a full weld repair is itself a temporary repair which should be postponed for as long a possible. The cracking has not progressed into the parent material and there is evidence that the...

Dear all We have a CrMoV turbine casing with a large crack (35 mm depth). We have come to the conclusion that we do not want a full weld repair because of distoration concerns. We believe that it would be acceptable to leave the crack in situ as it is below the crical size. The cracking is...

GRoberts The material is a Parsons propriety alloy with composition of C 0.07-0.15, Mn 0.3-1, Cr 11.5-13, Mo 0.40-0.80, V 0.10-0.25. We have tried the 410 filler with a minimum preheat of 250C which we maintained for 2 hours after completion. There was no cracking on cooling and a hardness...

GRoberts, thanks for the reply. Following your response, I look up the specifcations for the E410NiMo filler. The maximum PWHT temperature specified is 620C (1150F)whereas the tempering temperature of the base material is in the range of 690C. I have also looked at that other weld procedures...

Dear all We have a steam turbine nozzle block that is made from a martensitic stainless steel (similar to 422). The nozzle assembly is fabricated from individual nozzles which are welded together. The weld material is a nickel based alloy believed to be Inconel 182. We are currently...

Dear all We have a steam turbine nozzle block that is made from a martensitic stainless steel (similar to 422). The nozzle assembly is fabricated from individual nozzles which are welded together. The weld material is a nickel based alloy believed to be Inconel 182. We are currently...

My understanding is, , that the PWHT requirements are specified in AS4458 (see table 14.1), as per AS1210 table 1.6. For example for CS materials (group A1) PWHT is generally not required for thickness below 32 mm. In your case, I agree that it would not be a wise to PWHT as the PWHT...

Hi I cannot answer your question directly as I am not sure which clause in 1210 calls for PWHT of all class 1 pressure vessels? Cheers

Rafi BS7910:1999 appendix U has constants for creep crack growth estimation for a number of materials including CrMoV.