Super duplex and 6 moly alloys generally resist well to pitting (I'm echoing 'EdStainless' post); however I would suggest to perform ASTM A380/ 967 tests or perhaps just ferroxyl test as per 380 should be enough to determine the cause of free iron on the surface - is it truly mild rust staining...
Attachment welds heat treatment requirement is strictly based on metallurgical requirements and not service requirements. Hence, if your fired heater coils are designed as per B31.3 older version (2015 edition mandates PWHT for all P5B), then you must stick to that standard. These PWHTs are...
thread292-374408
When Appendix HH refers to Appendix A for the leak testing, does it mean U tube bundle expansion joints are also covered under this Appendix? If HH-1(b) and HH-1(c) are required, then Qualification test is not needed.I assume in a U tube bundle, a single tube is joined to the...
Is there any relation between the shear load test of an expanded tube to tubesheet joint and the leak tightness of that joint? I'm struggling to understand if the mechanical design is confirmed by such mock-up testing, how joint efficiency and the leak tightness are related to such destructive...
Shear load testing or pull out testing of fully expanded tube to tubesheet joint at lab conditions may not prove the joint integrity at the operating conditions. Though this is only a mechanical strength test and not a leak test, how this mock up test can ensure that the maximum allowable axial...
I've read serious furore over the purpose of such pressure testing, calling or guessing it as strength, full stress, proof, integrity, load test, confidence, second NDE, simulation, mock-up and so on. My question is towards a paper submitted by a Japanese company in one of the Pressure Vessels...
Thank you for providing valuable answers. Can I conclude that the short answer to my original question 'How successful the current industry practice on not coating the CS surfaces with insulation (microporous or flex aerogel) operating below 150 C?' is - Larger number of corporations do not coat...
I've come across certain investigations pointing out the loss of anti-seize compounds in internal fasteners on bolt relaxation issue. Another issue was the contamination of clean service fluid. Now that you've confirmed that this is purely operating companies' requirements, I'll not attempt to...
Thank you GR2vessels. I repent on my slip- It should be A216 WCB not 316 - pardon my inept typing. My question is around that piping or vessel spec. Do they govern the safety relief valve body when they are not exposed directly to operating fluid. Most of the safety relief valve design have...
In most safety relief valve construction, the service fluid does not come in continuous contact with the body material. Is it an acceptable practice to design the pressure relieving valve body based on pressure and temperature alone ignoring the fluid corrosion/erosion properties? I have not...
Thank you Muld. I meant only anti-seize compounds which influence nut factor. In addition to process fluid contamination, this lubricant, in most cases, will be carried away by the fluid stream. That is the chief argument against the use of lubricant on internal fasteners. I was looking for a...
Thank you for the responses. I've seen in the past that rolled tubes start relaxing when we roll soft adjacent tubes (like brass or CS). That is why I was wondering how come there is no recommended practice available. Inside - Out approach seems to be good to address this issue. In the case of...
Under what conditions Shell and Tube heat exchanger internal bolts found in floating head flange, baffle plates, tie rods need not be lubricated or coated? I understand the process fluid generally washes out the coatings on the fasteners. In that case, the available clamp force on the fasteners...
Thank you Ed. In that case, for a new design, it's just an option for the operators? Higher alloy, high pressure, critical service are some of the terms I used to hear for specifying tube joint mock-up. There must be some international standard which recommends to perform Section IX QW 193...
Are there any guidelines as to when a mock-up of tube to tubesheet joint would be recommended? Such an 'engineering judgement' is highly subjective, similar to defining what is 'critical'.
