Hi All - We're trying to settle a debate internally. We have a Section VIII Div 1 vessel where the shell wall was hit by a cutting wheel while removing a weld. The shell wall is 1/4" thick and made of formed plate; the gouge groove is about 1/8" deep x 1/8" wide and 1" long (very smooth/regular...
Hello,
My company has an application where we use welded 316L plate at elevated temperatures (250F-300F) in a steam environment with chlorides present. Historically, we have seen issues with pitting, SCC and generalized chloride corrosion in the heat affected zone of the welds. We are...
We have a single side weld v-groove joint made from 1/4" thick 316L with backing. It's welded in flat position and we require full penetration. We're looking to change the weld process from GTAW to GMAW. For this joint we're sensitive to both chromium carbide as well as oxide discoloration. We...
Hi All,
I have a design that I'm trying to analyze by hand calcs before I use numerical methods (FEA). I'm working on beam calculations for max shear/moment so that I have something to validate against an FEA result. The design involves applying pressure to two flat plates that are joined to...
Hi Everyone,
I know the topic of pressure part versus nonpressure part has been asked before and these are good threads:
http://www.eng-tips.com/viewthread.cfm?qid=311069
http://www.eng-tips.com/viewthread.cfm?qid=182988
http://www.eng-tips.com/viewthread.cfm?qid=255317
Additionally, I have...
Hi All,
My company has a Section VIII Div 1 vessel that has been in steam service for 2 years and has developed a crack in the jacket. I attached a picture of the defect for reference. The vessel is a flat wall cross-section with a stainless steel inner wall, 516-70 jacket (1/4" thick) and...
Reading UG-101(d)(1)(c) the code explicitly states that for a burst test to cover "duplicate parts", the duplicate vessel must have the same nominal dimensions (width, height, diameter) as the burst vessel. This section says that duplicate vessels may not have longer lengths but allows for...
I have a Section VIII Div I design where I am trying to size bolts for a very unusually shaped flange. Because of the shape, the load on each bolt is different - both in terms of tensile stress and bending stress. I have experimental data on the resultant load on each bolt. When I examine the...
Hi All,
In our application we are MIG welding an A36 bar to one side of a 1/4" thick plate of 316L. The side of the plate without the bar is exposed to a corrosive environment. Currently we have two approved processes for joining A36 to 316L - one uses a 316L consumable and the other uses a...
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We are working on a design for a Section VIII div 1 vessel that will need to have stiffening bars welded to a flat head in order achieve the desired working pressure. I am trying to source a bar specification that is available in square/rectangular shapes and cold rolled. Ideally, I...
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I am trying to use Solidworks Simulation to analyze a design that I have already validated by hand calcs and physical testing. Basically I have a flat rectangular plate that has a uniform pressure on one side. The opposite side of the rectangular plate is supported around the edge by...
Hi All,
We are preparing to perform a burst test in accordance with UG-101(m). Our inspector is insisting that UG-101(h) applies and that we must bring the vessel up in increments of 10% of the expected burst pressure and then reduce the pressure back to atmosphere prior to the next iteration...
Hi All,
My company is transferring a Section VIII Div 1 design to production. It is a low pressure (50psig) and non-lethal service application. We have spec'ed out bolts that are SA-193-B7M. My question is regarding the traceability of these bolts. According to section 18 of the spec for...
I've seen a number of products coming out that are nano-particle based super-hydrophobic spray coatings. The companies themselves seem to have no information other than an MSDS documenting heath risks. Unfortunately, the MSDS lists the product as "generally regarded as safe" based on the...
Hi All,
I'm working with NEC 310.16. Most wire terminals that I've encountered are rated for 75*C. I understand that that many people will use 90*C wire because then you apply derating factors for ambient temperature and number of wires in a single conduit without having to drastically...
Hi All,
I'm working on a project where we have to create load ratings for some really old mezzanines that exist in our facility. The load on the mezzanine is really low (~25lb/sqft) but we want to put a number to the max allowable load. I found all sorts of sample calculations that I can...
Hi All,
I have an application where I am hinging a heavy door and to trying to minimize the hinge friction. I started a thread in Mech Eng Design (http://www.eng-tips.com/viewthread.cfm?qid=331769) but it seems my question may be more appropriate for this thread. I apologize for the cross...
Hi Everyone,
First off I want to thank everyone for making this forum so great and being so helpful! My company is working on a project and I just noticed something in the specification that I don't know is even possible. The equipment has a large door that weighs 2,500 lbs and the hinge pin...
Hi All,
Just an FYI - font size must be >=8 for regular text or >=7 in tables for all forms submitted to the NB. We just had NB return 100+ U1 reports back to us because the font size used was too small. We've been using the same font sizes for 10+ years without any issues. According to our...
Hi All -
Mech E with very limited EE background here. I have an application where I have a tank with 2 level switches - a high limit and a low limit. When the high level switch is energized my tank is full and the pump should be off. As the level falls, nothing should happen until the level...
