Metal seats do not tend to be bubble tight, as I would assume thats why soft seats are being used.
That said triple offset valves are a 'metal seated' but comply with soft seat leak rates.
Soft seats do not like uneven temperatures, if the valve is cold and one side warms up the disparity in...
To answer your questions though:
1. Yes depending on what standard you want to comply with.
2. Installation should be no more than 45 deg from vertical.
3. Yes, these valves will typically get to lower temperatures.
4. As Q2
Stem position and length apply to any type of valve, ball, gate TOSV...
Take a look at FAQ 774-566 its for Cryogenic valves but also relates to low temp valves such as you require.
The shaft can be as much as 45 degrees from vertical if the extension is long enough, try and comply with a known standard such as shell's then you cannot go wrong, these have been put...
In response to jabonet's original question, can I suggest a basic increase in good thick insulation to stop the valve reaching higher temperatures and as the valve gets down to -196 the material will be kept colder and may even stay chilled for the next days operation, if it does you will then...
It sounds as though you may be talking about a Double block and bleed valve, the 'o'ring allows the seat to move with the ball slighlty yet still seal against the body of the valve stopping any flow across the back of the seat.
Pressures are lower than normal use because of the 'o' ring...
unclesyd is mostly right, the other point is that the vee port was either a metal seat with the formed aperture and the use of a standard ball, or a solid ball machined with a parallel cutter forming the 'Vee', the Vee that is talked about here and the ones we made have a tapered Vee, this...
We made a very similar item many years ago in NJ from a solid ball. However it was not actually given a name as it was the customer themselves who provided the sketch.
The stops were changed to allow the ball to rotate 180 degrees. As far as we were concerned it was a very crude manual control...
roadbikeruler (Petroleum) says
so I pressume he does mean 100% Glycol.
Surely this is quite a difficult test, much like Helium against Nitrogen when doing gas tests, as the Glycol has a very small molecule and is known to be very 'searching'. This would surely find leaks that would not...
Jspisich -
You don't need a 'vent' to eliminate pressure/vacuum if you use a diaphragm, therby maintaining the 'atmosphere' within the unit. Obviouisly designed large enough to cope with temperature changes involved.
B
Sorry this is rather fractured.
I have always found great difficulty getting negative temperature properties for metals unless they have been specifically designed for that purpose i.e. 17.4 ph 1150MM.
In the years I have been in Cryogenics we have always had to approach the manufacturer for...
zdas04 (Mechanical)-
Don't mislead the guy by stating that all 'Trunnion' ball valves have springs as you did in thread408-134074. Take a 'Jamesbury' 10" 6000 series, these purely use polmer seating technology and a very unique design to load the seat onto the ball despite being trunnion ball...
Take a look at FAQ 408-589, I wrote the FAQ quite some time ago but it still gives a good representation of the facts.
These are general fire testing standards for 'any' application where the valve must isolate a potentially volatile media. Most 'certified fire tested' valves can be used for...
