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Thankyou all for your help. Cheers

Thanks for your comments. I now see the advantage of using portable blowers to dry the refractory in order to keep the shell temperature down. T/C's on the shell is another good idea. What is the exact lower critical transformation temperature for 1.25Cr 0.5Mo? I have done a quick search on...

Hello all, I am getting a refractory lined vessel fabricated for hydrogen service (reformed gas outlet header) and I am concerned that the refractory dry-out temperature and duration will cause material degradation to the 1.25Cr-0.5Mo shell (1100mm OD, 20mm thick). The dry-out schedule states...

Thankyou all for your help, it has answered all of my questions. Montemayor, I may have not explained myself well but for your information, it is a plant that makes ammonia (at approx 10 000kPa and 420 deg C) and the same ammonia is also used as a refrigerant to cool it to –33 deg C for...

Hello all, In our refrigeration area of our ammonia plant, we have numerous double block and bleeds for isolations. As these isolations are carried out infrequently there is no hard piping on the bleed/drain line to vent. So, once the two block valves are closed, a flexible hose is connected...

That's correct, it is direct coupled to a 4 stage integrally geared compressor.

Are there any standards or requirements that dictate how a steel motor base/platform should be designed? ie. Should it be completely rigid or is some flexibility required for start-up torque? Are there mass requirements? etc. I want to modify a steel structure designed for a 2.2MW motor so a...

Hi, Can somebody please tell me the chemical composition for ASTM A672 Gr C70 Cl 22? I cannot find it in any of the specs. Is it similar to ASTM A106 Gr C? Thanks a lot for your help. Mad Dog

Thanks for the explanation. Do these low temperature materials also have a upper temperature limit?

I am wondering what is the definition of "Low Temperature Service". For example, what is the max temperature that a ASTM A420 Grade WPL6 elbow can be used? How do the chemistry and mechanical properties differ from non-low temp service? Thanks in advance

Thankyou all for your help. You have given me many options to to follow up. Cheers

Thanks again, great stuff. We have a 5000t ammonia tank approx 4 years old. AE testing was done prior to initial filling and I am now looking at what needs to be done on this tank in the future as part of the inspection program. Approx how large does a SCC crack have to be before it is picked...

Thanks for that metengr - very informative. Cheers

I have read that between 100ppm and 1000ppm of water should be added to liquid ammonia being stored in carbon steel tanks (-33 deg C and ambient pressure). How does the water addition eliminate the risk of SCC? Also, can SCC occur if there is no oxygen present? Thanks in advance for your...

Thanks for your help – you have given me some food for thought. The vessel is a reformed gas outlet header (hydrogen service) operating at about 2000kPa and 800 deg C. Although the production team would probably like us to carry out this repair when online and hot, we intend to cool it down...

We have a refractory lined cylindrical pressure vessel which is exhibiting some hot spots due to gas tracking through fine cracks. The vessel ID is too small to repair from the inside so I wanted to weld some 1/4"- 1/2" nozzles onto the vessel and inject liquid refractory from the...

Thanks for your responses. I agree that it is a very dangerous situation and I am just sounding out options at the moment. The 930F temperature was the hottest of the hot spots, this one on a 1.5Cr 0.5 Mo section of the vessel. The remaining hotspots are around 700F on carbon steel. These...

We have a refractory lined, carbon steel collection header which has sustained localised refractory damage and subsequent hot spots. We are unable to shut the process down to repair the refractory so I want to investigate an on-line “temporary” repair. I am proposing to weld nozzles onto the...

We have a refractory lined, carbon steel collection header which has sustained localised refractory damage and subsequent hot spots. We are unable to shut the process down to repair the refractory so I want to investigate an on-line “temporary” repair. I am proposing to weld nozzles onto the...

We have a pump casing made from L-14 iron and we want to know if we can carry out some minor weld repairs. After some searching, I have not been able to find a material chemistry. Does anybody know of this material and can it be successfully welded. Thanks