Hi All,
I am in agreement with BigInch, the codes that we deal with over here in the Power Gen industry are generally British or German. They warn against any attachments to pipe in the creep range as they are stress raisers and additional points of inspection during an outage, which is costly...
Hi Mehdi,
BS 806 requires a 1/100 slope with the flow for steam lines and a 1/40 against the flow for steam lines. Some of the clients require that more slope is used, but this generally causes other problems with weld fit-up and the use of pulled bends to accomodate the slopes, which is...
If you use a vendor catalogue i.e. Main Industries. they give snaking calculations, expansion loop and anchor block load calculations based on field operation and strain gauge testing.
The HDPE pipework will snake, one just has to calculated the amount of snaking, and position guides and anchor...
Hi Philip,
Have a chat to Eric van Zyl & Alan Stewart on the subject. API 520 & B31.1 give guide lines as well as the Crocker & King, pipe break & associated thrust loads. CII has a good relief valve calculator in the Dynamic Analysis part of the program.
Cheers
Rob Stephens
(ex-Steinmuller)
Be very careful of using ASME B31.3 for FRP analysis.
The vendor should always be consulted on the properties of their products for FRP. A stress analysis package that can combind the different types of manufacturing methods of the pipe/fitting needs to be used, Caesar II/Triflex etc, consult...
Thanks to all who responded.
I personally prefer to be more conservative in my designs. I suppose it's purely to sleep better at night, having worked on a site for a few years and even with all the response to this thread. Those who prefer to take it to the 'max' - enjoy!
After reading the SIF...
Hi bvi,
The sections from the code (B31.3 & B31.1) that I am refering to are 304.3.5(a) & 104.3.1(F), the design of the tee's as per code are purely for pressure containment, further applied loads need to be considered by the designer and in the case for B31.1 are covered by the use of SIF's to...
Hi all who may be interested,
After a bit of research, I have found that if one apllies the SIF and allowable design stress criteria of ASME B31.1, then the external loads applied to the branches do not need to be checked.(As per the B31.1 code). This is not the same for ASME B31.3, which uses...
Hi SPLIT,
Do you know what design life you will be designing the pipeline for. The temperature takes the material into the creep range and depending on the layout of the system, you may want to consider pre-stressing the material to reduce the end reactions on your equipment, read up on this in...
Hi all,
I have a highly stressed welded tee(ASME B16.9). The stresses are not within the normal stress range allowables, but pass to the liberal stress range case.
Pullman Kellog states that the stress intensities added at the tee as per the code(ASME B31.3) cover the local & secondary...
Hi MIEngr,
Thanks for the reply.
The plant we are building is a Copper Refinery in Loas, the medium is at 244 deg C and 5450kPAg. The medium is a Raffinate off gas, pretty nasty stuff. The grade of Titanium that we are using is an AMSE B31.1 specified material, as it appears too be the only...
Hi All,
I am trying to get info on Ti Grd 12 flanges, I need to check the maxium pressure at temp. I cannot find the material group in ASME B16.5 to check the derating from the tables. Does anyone have info on the subject, or must the press/temp rating be calculated from scratch?
Thanks in...
Thanks to all who have replied,
Sorry for being slow to respond, we have over come the problem by discussion with the AIA & they will accept the area replacement method as defined in B31.1.
To Tony, a friend of mine A Stewart says to say hi.
Hi all,
I have a 28" to 28" 8mm thk fabricated branch, the design temp is 175dec c & press =1000kPa LPsteam. CaesarII tells me that the sus. & exp. stress is acceptable, the B31.1 code tells me that the area reinforcement required is ok. I have since done and FEPipe analysis on the...
Hi rkuhn,
I would tend to agree with you, if you look in the technical referenc manual of Caesar II, longitudinal press stress is=p(di+td)/4td & circumferential pressure stress=mp(di+td)/2td
