Having essentially the same question, I appreciate the references given above. This is what I found:
API 6A -- refers to "line pipe" thread rather than NPT. The now-retracted 18th edition had a note on interchangeability for sizes up to 1 1/2" with a caution that the slight variation in...
Regarding distributing hydrogen by pipeline, if the existing infrastructure for natural gas is to be used, there will be problems with hydrogen embrittlement unless the pipelines are replaced/upgraded. Depends on what those pipelines were made of.
Thanks for the responses.
This company has been in business for 25+ years designing valves to ASME VIII-2 App 4 and API 6A (which references the former). But I've only been here a short while, and already I find that I cannot rely on learning how to apply these standards by examining what was...
Thanks both for the input. I do understand the theory, but ASME dispenses with theory to some degree in order to apply tried-and-proved methods as industrial codes are want to do.
A couple of more questions. I had originally assumed that "linearization" meant "averaging"...
I have inadvertantly discovered that our valve-design calcs, based on VIII-2-App4, are done improperly, so it has been put on me to figure out how they should be done. So wading through the code for the first time, I am having similar questions.
For PL + Pb, 4-133 does say "highest value...
In my experience, manufacturers tend to be notoriously tight-lipped on giving some of these details...
That said, I have had success through FMC (Weco brand) and, to lesser extents, Kemper and Anson. So I suggest you try those. For FMC, try their Fluid Controls headquarters in Houston.
I, too, would say FNPT = Female NPT. The company that I work for routinely uses it to mean this. The "correct" (i.e. standard) shorthand would be NPT(F).
While welding of fully assembled valves is common, it is also common that this voids the manufacturer's warranty--but that's another issue.
Perhaps you should also look at the valve design. "Normal" turning torques depend on the design as well as the fluid pressure, so it could be...
As was stated by prex, torsional shear is greatest at the outer fibres. And as was stated by ivymike, piston pins are intended to rotate freely (so they don't transmit torque).
This makes me wonder if you're thinking of direct shear? There would be a direct shear in the pin at the transition...
In short, ATEX is a comprehensive European standard that merges and supersedes the various standards (like Cenelec) that were specified with "EEx ....".
As PeterCharles mentioned, this has been in progress for a while. It's part of the European Union's efforts to harmonize their...
Are you perhaps thinking of the hydrostatic shell test requirements?
ANSI requires that a shell-integrity test be done at 1.5X the rated cold working pressure. Note that API is somewhat different--they require 2X the cold working pressure for 5K and less, and 1.5X at 10K and up.
Your design...
Regarding the hard/soft issue, if there is any likelihood for abrasive particles to get between the plate and the stop, then I would suggest that both should be hard. The reason is that such particles would tend to imbed in the softer item and then abrade the harder one at accelerated rates...
