Recent content by LT Judd

I have some experience, (theoretical and drills only) from merchant marine and have actually done something similar on a fire fighting course. Typically, as non professional fire fighters we would always seek to use existing opening like doors , windows, access hatches rather than cutting...

Thanks for your help. Your post got me pointed in the right direction, and I investigated the "thick wall" equations known as Lame's equations. These can be regarded as the "true" case but are quite a bit more complex that the ASME formulas , thus more liable to produce human error mistakes...

Okay, I get it, ....I think. So obviously in real life the pressure only acts on the internal surface, i.e the inner diameter, not the mid-wall diameter or the whole diameter. Unless they are saying there is some kind of diffusion through the metal ?? Otherwise its just some kind of empirical...

The ASME BPVC formula is t=PR/(SE-0.6P) where P = pressure , R = inside radius, S = allowed material design stress and E = joint efficiency factor. the AS1210 formula ,(equivalent nomenclature) is t=PR/(SE-P). This makes 1210 more conservative when using the inside radius . I suspect the pure...

Steel and other metals data sheets and mill specs most commonly quote some tensile strength metric, like Proof, Yield or Ultimate Tensile Stress. Less common is the value for shear strength. Often as rule of thumb the allowable shear stress is taken as half the allowable tensile stress but, when...

Hi , I am based in Australia and my question originates from some grey areas in the Australian system of classifying pressure vessels. I am guessing most users on this forum are US based . Does the US have a system for classifying pressure vessels such as air receivers , boilers, autoclaves...

I could stand corrected, but I believe It has been shown clearly that the gene for blue eyes is recceisve . That is both parents have to carry the gene ( they don't both have to actually have blue eyes themselves) , for their child to have blue eyes. If one parent doesn't carry the gene, their...

My question relates mainly to mechncial engineering but I guess the general principle may apply elsewhere. Up until now I have mainly been an engineer on the customer side (marine and offshore) , reviewing contractor reports, "sense checking" them and general engineering firefighting and...

Hi Chester, Sorry for the late reply, I wanted to have a long think about it. Yes I am familiar with polar co-ordinates and unit vectors , but I dare say not as much as you are. I just struggled with some of your notations and sign conventions. Anyhow , I decided to look at this another way...

Sorry , totally lost me there. Is the units of T Newtons ( or kN) ? and does ## i_r ## means the unit tension vector in the radial direction? I also don't understand the notation ##i_\theta (\theta)##. Why is ## \(theta) ## written twice and which one refers to the direction and what does...

Good Day Chester, I thought I would have a crack at the FBD. see attached- does that look right? Being a ring rather than a disk I assumed that there is no inward radial force, not sure if that's correct. So based on the FBD and the arising formula, it appears that the hoop forces could be...

What was happening when the guy poured liquid gasoline into the manifold was that a very small amount would have vaporised. When it dripped into the cylinder a little more would have vaporised. When he started cranking the engine a little more would have vaporised. But you notice it took...

I can't see how electricity generators can make money. I am from Australia so multiply figures by around 0.7 to convert to USD. Electricity prices and power generation have become a bit of an ideological battle ground in my country so prices are in the news . Whole sale electricity prices seem...

Sorry didnt explain myself very well, Its really a maths problem rather than an engineering one. I am trying to do a cost comparison of different types of power generating plant. One standard way to do that is to find a known plant of a certain size at a certain time in a certain place and then...

No, For the first formula, it's total capital cost so for example it might cost 200k to purchase an 11 tonne per hour boiler how much does it cost to buy a 25 tonne per hour boiler if the exponent is 0.7. I understand that part. What I want know is what's the formula if instead of $ for...