Dynamic load factor does come from cyclic loading as the load is taken up and released. Surge loads can ONLY be estimated when you know the surge pressures, and that comes from transient flow modelling of the system. I can send you a paper on the subject if you like.
Yes, that's correct in some situations. However you need to be aware of the amplifying effect of harmonic motion in the pipe and to represent this there is a so-called "Dynamic load factor", which can be up to 2. If unknown, the safe assumption is to multiply the answer from BigInch's method by...
PS I should also have said that these programs only work out pressure-time history, they don't calculate forces on pipes, but I can help with that if needed.
Stuart
vodeni,
Someone has obviously considered water hammer (also known as surge or transient flow) there since you refer to a "surge relief system".
As eadwine states, such conditions occur whenever there are flow rate changes. Normally these are slow enough not to give much problem with pipe...
Thanks, I'd have expected that too, and am presently making that asumption. I've got the flash points data from several hits using a search engine, but they don't mention this and I don't have a copy of the original document (and am having difficulty persuading my client to buy one!) which in...
Matt, Many thanks, it looks interesting. At 365 pages it's going to take a while to digest!
Wilton / Billingham is a crying shame (as is most of British manufacturing industry). When ICI built it, it was a great complex, as was Runcorn, and we were proud to be part of one of the world's...
No, I live in Chester. I lived in Normanby until I was 18, Dad now lives in New Marske. I worked for ICI for 20 years in mid Cheshire and Runcorn, spending some time on project work at Wilton in the 90s. Since leaving ICI in 1998 I have done a few months' work for Invista (sadly plant now...
Thanks, I've sent an e-mail to Siemens, see what transpires.
Curiously, Prosalus turn out to be a company whose office is about 10 miles from my father's house in Teesside, so I'll contact them and maybe get some customised help if I can call in some time. I don't really need a course, maybe a...
Thanks for your replies. What you are saying all sounds in agreement with what I thought. I don't know anything about data highways - but I can imagine. I seem to remember being told about various protocols for LANs many years ago which involved packets of data being sent around - I guess the...
Russell,
Thanks for your reply. I did look through the various forums and thought this was my best bet! Maybe not, but if you are happy to try, so am I.
PFD=probability of failure on demand, ie (say) the level gets higher than the trip point. PFD= probability that the system of level...
I'm a chemical engineer in England, involved with safety integrity assessments for chemical plants. I'm struggling with understanding the meaning of multiplicity, or redundancy, inside modern DCS systems, which is often relevent to these assessments.
We work to BS EN 61511 / BS EN 61508, where...
mprice,
Sorry, I gave a false "OK" to your re-arrangement which explains your problem with substituting numbers since. The correct re-arrangement of my equation is
dT = [Q.L.ln(Xh/L)]/kpZD
If you look at my worked example you'll see that's what I used to get the sensible answer of 24.92 degC...
It depends very strongly on the particle size and dryness. If your particles are small, say substantially below 100microns, and dry, then yes it will be explosive at much lower concentrations than 70%! 20-40 g/m2 is a decent guess, and this is quite dense, enought to obscure a light bulb at say...
mprice, yes, you re-arranged the formula correctly. As sailoday28 pointed out I've omitted the minus sign - pure laziness! You can ignore convection, but beware ignoring radiation unless your temperature is similar to the surrounding temperature.
If I substitute into this equation, I get for...
