Elbow wall thickness thinng
Elbow wall thickness thinng
gafoorkti;
What was the code of construction specification for the new elbows?
What was the code of construction specification for the new elbows?
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Elbow wall thickness thinng
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RE: Elbow wall thickness thinng
h ttp://uk.l inkedin.co m/pub/terr y-roberts/ 28/a9a/a10
RE: Elbow wall thickness thinng
RE: Elbow wall thickness thinng
Please let me know the following:
1)Is there any alternative method to check the thickness?
2) What is the permissible variation for positive tolerance (+12.5%?)?
3) Will process code/construction code (ex: ASME B31.3) allow thinning at bent section?
Regards
RE: Elbow wall thickness thinng
Please see the excerpt from B16.9 below regarding design of the fitting.
2.2 Design of Fittings
The design of fittings shall be established by mathematical
analyses (e.g., ACME B16.49 for bends) contained
in nationally recognized pressure vessel or piping codes,
or at the manufacturer's option by proof testing in accordance
with para. 9 of this Standard. In order to meet
design or manufacturing requirements, it is expected
that some portion of formed fittings may have to be
thicker than the pipe wall with which the fitting is
intended to be used. The mathematical analyses, if used,
may take into account such thicker sections. Records of
mathematical analysis and/or successful proof test data
shall be available at the manufacturer's facility for
inspection by the purchaser.
Unfortunately, ASTM A 234 does not provide any guidance for minimum wall thickness for a elbow, only material specification information.
As I mentioned previously, you need to know the code of construction for installation of this fitting. If the fitting is certified to B16.9 from the supplier, discuss with the supplier the minimum wall thickness.
RE: Elbow wall thickness thinng
303 GENERAL
Components manufactured in accordance with standards
listed in Table 326.1 shall be considered suitable
for use at pressure-temperature ratings in accordance
with para. 302.2.1 or para. 302.2.2, as applicable. The
rules in para. 304 are intended for pressure design of
components not covered in Table 326.1, but may be used
for a special or more rigorous design of such components,
or to satisfy requirements of para. 302.2.2. Designs
shall be checked for adequacy of mechanical strength
under applicable loadings enumerated in para. 301.
RE: Elbow wall thickness thinng
When you pull out API-570 and calculate the [pressure-only] Tmin, you will find out that very little wall thickness is needed to contain the pressure of the fluid in your pipe. This is why the industry standard 87.5% has been around for over 50 years, without causing any problems.