The most important point to check is always what the enduser/customer actually expect,. This might be based on his experience, 'way of doing things', unwritten branch customs or earlier deliverance from your competitors.
This can differ from what current and validstandards actually says, and...
Not sure this will qualify. The link is for a small specialized US company, that has supplied special designed valves with positive rusults for some very difficult and demanding cases in my past career. If knife-gate valves type constructions are considered this is a type of construction you...
Hi,
I would suggest a look and search directly at some of the worlds leading suppliers to catch the latest development. As excammple, link to two, more will be found by search.
https://www.valmet.com/search/?q=cryogenic+valves
https://www.oswalvalves.com/company
...what about the fluid you are handling? Gas, liquid, mixture, temperature, pressure, residents, additives, abrasive (unclean) fluid, operational cycles, occasional empty pipeline, cleaning process/fluid, earlier repair.
More likely a failure from one of the reasons above, but could also be...
If available in size and pressure class needed I would have suggest a ceramic (or ceramic lined) ball valve. I do not know however if valves available on the market also are qualified with the necessary certification. You could check Valmet/Neles or others.
I agree, seems likely that the start of the failure might by attributed to 'group three'.
My thought is that if the valve in addition is stuck, the T-connections upward moment could lead the stem's T to eventuallu to be stuck (not rotate) against top of the avaiable room. This again cold lead...
I have no experience with this particular valve.
With no informaation about use (media, prussure, age, operation cyclus, possibillity of orrosion and abration etc.) we are stuck with 'educated gussing'.
In my mind the most likely possibillities are:
1. Wrong use, installation or operation...
You won't find any references for flange repair in any valve spcification for certified valves. The reason is that this is not seen as a possible (allowed) variation. If you use a valve with repaired flange, you will also have the full responsibillity for the conseqences, morally and economical...
If the valve is working OK by a lower pressure, you can be fairly sure that the problem is not electrical.
Most common for all types of solenoid valves are mechanical problems. Most common is dirt partly plugging bores or lines, hindering movements of plugs, stems or membrans, or also causinng...
It could be, as you suggest, be a pure check valve, perhaps with a disc hinged in the middle. The top suggest however that a pring is involved.
It could then also be a disc or diaphragm valve where the disc is pressed up by the increased fluid pressure and down by spring force.
As the valve...
I have positive experiences with the linked below factory, but not with high temperature valves, or for hydrogen. I would suggest that you search for North Sea offshore valve suppliers. Study of details/samples below might help you-...
Hello moideen,
This is a classical example : everything is OK but the end result. As mentioned by others (I do agre with the posts above) several things might be wrong. With stainless steel as spcified for the disc, it is more likely that the pistting is cavitation corrosion. This should...
Thanks for this information, with all symphaty to the victims and their families.
We can always improve products technically to prevent wrong operation or demounting. But, again, nothing can 100% protect against an operator with insufficient knowledge of the product.
For pressure retaining...
As known a butterfly valve with a nearly closed position will very often come into cavitation range. Anyway the practical regulation range (allowable throtteling) of a butterfly valve is limited. THe quality of the BF valve should also come into consideration (costruction and closing areas...
You have alreedy got a lot of information. The question from my side is what you need the information for. You would probavly get better answers if we knew the purpose of the comparisons.
ARAK25, Thank you for clarification! I agree fully with both you and BCD. In my opinion (also) the manufacturer has supplied to ordered specifications. If additional info's or papers/tests are requiered this should have been specified.
With pneumatic actuators with different positions regulated by air pressure to one or both sides, the only way to ensure the valve remains in the exact position if a failure accurs, is to lock the air supply to both sides of the actuator.
The conservative (safest?) way to do this is to have...
