Occasionally our maintenance engineers report leakage in drips per minute. Fluid is water at various temperatures. I'm guessing the droplet size is related to viscosity and surface tension properties at different temperatures.
Has anyone got a link to an estimate of typical water drop size at...
A colleague in Sweden is in the process of designing a new flange joint bolted together with bolts (M30 to M100). Current calculation methods within the department are 10+ years old and are limited to typically 45% of the yield stress of the bolt shank, this limitation is due to the stripping of...
I was asked to check the torsional stress in the wire of a spring and plugged the numbers into the standard equation from the text books:
shear stress = (8 x load x mean diameter x w-factor)/(pi x wire-diameter cubed)
I was surprised to get a result which exceeded the shear ultimate stress for...
We manufacture nuclear valves to ASME III.
Some of our older designs have surface finishes on internal surfaces of 16 micro inch, which is hard to achieve.
It has been suggested that this was introduced to prevent cracking due to thermal shock and that this was derived from a requirement in ASME...
I have a project to find reliability data for valves in nuclear power plants.
Can anyone advise me of sources of such data.
I have started to work through some of the sources listed in the following site:
http://www.risoe.dk/rispubl/sys/ris-r-1235.htm
Bill
I have a project to find reliability data for valves in nuclear power plants.
Can anyone advise me of sources of such data.
I have started to work through some of the sources listed in the following site:
http://www.risoe.dk/rispubl/sys/ris-r-1235.htm
Bill
I have a project to find reliability data for valves in nuclear power plants.
Can anyone advise me of sources of such data.
I have started to work throughsome of the sources listed in the following site:
http://www.risoe.dk/rispubl/sys/ris-r-1235.htm
Bill
I am having trouble with erosion damage to a relief valve pilot seat from wire drawing in a steam application. The Stellite 6 seat is tapered and gives contact at the top edge. The poppet is of Stellite 12 at slightly shallower angle, about 60 degrees inclusive.
I have been advised that...
I am having trouble with erosion damage to a relief valve pilot seat from wire drawing in a steam application. The Stellite 6 seat is tapered and gives contact at the top edge. The poppet is of Stellite 12 at slightly shallower angle, about 60 degrees inclusive.
I have been advised that...
The usual loaded pin galling pressure test runs at relatively low surface velocities. I am told by one of our valve suppliers that they had extensive difficulties with self-mated Stellite 6 in water when the operating speed of the valve was increased to slightly over 1 ft/sec. Below this it was...
The usual loaded pin galling pressure test runs at relatively low surface velocities. I am told by one of our valve suppliers that they had extensive difficulties with self-mated Stellite 6 in water when the opeating speed of the valve was increased to slightly over 1 ft/sec. Below this it was...
I work with systems engineers who use the Crane 410M book for resistance calculations using resistance coefficient K.
First question is K dimensionless and the same value for calculations in US gallons/minte and litres/min.
Second question. A lot of the valve manufacturers quote flow...
I am doing some analysis on a relief valve with bellows sealed stem.
What area do you take as the pressure area of the bellows?
Is it internal/external or mean of the convolutions?
TIA
Bill
How frequently are PWR Safety Relief Valves tested?
Are they generally tested in-situ or removed to a workshop?
Are they tested on the operating fluid and temperature?
Are there any code requirements relating to this?
I am an experienced mechanical engineer who has made a new start in the valve design side of my UK company within the last year, after 30 years experience on unrelated equipment. A former colleague sold me a text book on valve design. Being a sad geek I took it on holiday with me to read and...
