Thanks for all your responses. Any idea about ASME Sec VIII Div 2 limit of 204 Deg C for UNS 31803 whereas limits in Div 1 and B31.3 are 316 Deg C.
With best wishes for Christmas and a Very happy New Year.
Impact values reported in MTC are in the range of 150 joule, is it possible to get so high values with no or incorrect heat treatment of flanges?
Normal operating temperature for the heating cycle (heating cycle time duration is appx 1/ 4 of total cycle time) is appx 250 - 255 Deg C and there...
One of our facility is operating under thermal cycle with temperature raging from 60 Dec C to 260 Dec C. After operating it for appx 5 years, we found some cracks on our piping system (flange and flange to elbow weld joint/ HAZ) which is in DSS UNS 31803 construction.
We send this piping...
Terms RF pad and doubler plate are commonly used with same meaning. RF pad is however to provide reinforcement to any opening or a load bearing component where existing shell/ head thisckness is not sufficient.
Double plate on the other hand is just a barrier/ pad plate which is of the same...
Dear JTE/ Duwe6,
Thanks for your response. Yes this requirement is not properly written in ISO/ API and is leading to confusion. I wanted to check if I am missing any thing on this requirement.
JTE,
API 661/ ISO 13705 require full penetration weld for the stay plates and for partition plate if...
Not sure if I am reading it correctly as to why a full penetration weld joint preparation is required for the seal weld? In addition, seal weld from both the sides will not be possible if the air cooler is multi pass with more than one pass partition plates on the header or have stiffener...
This practice of considering MDMT as -29 Deg C for CS and -46 Deg C for LTCS is commom. Some time it is due to ignorance and many times as engineering of convenience in order to limit and also standardize piping classes. This does not mean that we can blindly follow this practice, such cases to...
As per the requirement of ASME Sec VIII Div 1, PSV set point (start opening) can not be more than MAWP in case of single relief device. It shall prevent pressure from rising more than 10% or 3 psi (which ever is greater) above the MAWP.
Bayardwv,
Isn't the tube plate design and construction remain the same even with the drain connection on it (except for the drain connection)? This plate will still see only the differential pressure within the filter housing.
A sketch will be helpful to understand the construction of drain...
UG-20(b) requires that for the marking on the nameplate, MDMT to be established for largest value of MAWP. This clause also allow us to report additional MDMT corresponding to other MAWP's.
In case your process ensures that the MDMT of -238 Deg F can not occur at a higher MAWP, you can also...
Please refer to UHA 51 (d)(1)(a) which exempt impact test requirements for austenitic steel having carbon content less than 0.1% at MDMT -196 Deg C (-320 Deg F) and warmer.
Jtseng,
If I understand it correctly, your client wants you to weld load bearing support ring directly on the base metal and not on the clad or weld overlaid surface.
In such case, you have to strip cladded section, weld the support ring, weld overlay stripped section and them PWHT. As per...
Lets take an example of a small PV where a simple support (a simple plate)is directly welded (without any pad) to the shell (pressure part). This support may be bolted or welded to another structural member for vessel mounting, is this weld or bolted connection within code scope? In my opinion...
U 1 (e)(2) -where non pressure parts are welded directly to either the internal or external pressure retaining surface of a pressure vessel, this scope shall include the design, fabrication, testing, and material requirements established for non pressure part attachments by the applicable...
As per ASME Sec VIII (assume that this is the design code), calculation for MAWP is not mandatory and manufacturer can consider MAWP = design pressure unless calculation for MAWP is required as per the user specification/ contract.
In case manufacturer has already indicated on GA that MAWP is...
We never follow the philosophy of "MAWP not to be limited by flange". In case some one wants to follow this philosophy, needs to review the entire system/ process before implimeting this philosophy. Some of the main reasons for not following this philosophy are as below;
1. Assuming that MAWP...
Moltenmetal,
Going for next higher flange rating is not a small cost since up-gradation of only equipment flange and counter piping flanges will not help to achieve a higher rating for the complete system.
Complete piping flanges, valves and instrument shall also require upgradation for next...
Do not agree with the philosophy to increase the equipment nozzle flange rating just to meet MAWP requirement. All the counter flanges on the piping shall also require higher rating compare to all other flanges and valves on the same piping.
All the piping flanges and valves also require...
Midris,
Limit of 60 Deg C is coming from NACE MR 0175/ ISO 15156 requirements and is based on combination of H2S partial pressure and chloride content.
For offshore environment, SS 304/ 316 with a suitable external coating syetm can be used at higher temperature also if not limited by NACE...
ASME B16.9 may not be a true 2:1 ellpsoidal head as indicated by bpv66. I will prefer to mention std cap as per B16.9 instead of mentioning any ratio.
This question will mainly arise when we need to perform any calculation for the standard cap in case of any opening on the same. Any idea if 2:1...
