Air removal during hydrostatic testing of ball valve. 1

[Bharti__]

Hello!

I am working on project for hydrostatic testing of ball valve according to API 598. In this project, I am clamping the valve using hydraulic cylinder, Once valve has been clamped, pump wil start pumping the water and valve will start filling with water. I am planing to fill this valve vertically from downside fixture plate to remove air from valve from upper fixture plate and arrangement of holes has been made in the clamping fixture plates.

I am planing this whole experiment in such a way that you need to push button only once valve will be clamped properly. When you will push button pump will start pumping the water and once pressure is acheived timer will start and timer is stopped, valve will be drained from bottom side and cylinder will be retracted. this whole cycle will take only effort of putting valve on fixture plate and pressing the button.

But my only concern is While filling the valve i have to be sure that all air has been removed from valve before test pressure is acheived and for that i have provided hole on upper plate so, once operator observes that water is only coming out and all air has been removed then he will shut off the valve that is attached with that plate and pressure will start developing in valve.

In my whole project this is the only thing for which i am not getting any idea to consider it with automatic cycle that i have designed. I need a help for this that how can i make it auytomatic so at the end i need to push the button only and once air is removed it is automatically identified and solenoid valve there will close automatically.It kind of looking like in whole automatic/ Semi-automatic cycle only this thing of removing air during filling of valve is manual i want to automise it.

I need ideas and suggestion for this thing.

Thank you!

 

[Danlap]

Hi,

Not really a fan of fully automation on valves testing, since acceptance criteria is basically subjective when it is related to digital pressure fluctuation reading/measurement interpretation. And indeed, some of the contributing factor is due to remaining air pocket. Not necessarily a flaw, but when the pressure reading is fluctuated due to air pocket, it is quite often a debate between independent/end user inspector vs manufacturer's tester emerge.
An input of for your “clamp the flange & touch the button only (two motions) method”, is that one still requires to half open for example ball valve and after no air pocket deemed remains, he/she should close the valve manually. Given that handle size and torque value varies for similar and/or different type of valves, then fully automated this valve’s movement (half-open to fully close) is not suggested.

Not knowing the detail configuration of your design, how to know if there is no air pocket left? Both end of valve are connected to flange equipped with tubing orifice on its lowest side (downstream) and on its highest side (upstream or direction where the water comes).
Sequence: Valve half open > fill valve with water > when the lowest side tubing shows consistent water flow, then it is assured that water filling up and air “pushed” upwards > when highest side tubing shows again consistent over-flown water then valve is fully filled with water > close the lowest valve tubing (bottom flange) and then highest level tubing (upper flange)

The biggest challenge is that, what is the most accurate and economical solutions for one to know that the water flow is continuous (not pulsating, splashing, etc.). it is beyond standard flowmeter. Maybe a “camera” and then once it is visually continuous flow, then by a push of a button the tester close the tubing’s valve?

Nonetheless, good initiative and I wish you all the best with the endeavor.

Kind regards,
MR

https://nosuchvalve.com

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected

http://www.eng-tips.com/faqs.cfm?&rat1=2&fid=376

 

[Bharti__]

@Danlap

Thank you for your answer!

The sequence that you are thinking is almost similar to my project ( sorry cant provide whole configuraion before prototyping my project!).

But my only struggle is when you are trying to make it automatic/ Semi-automatic only one thing which is manual it doesn't go well with whole project. for now i am thinking to attach a manual needle valve at upper clamping plate so, when valve is filled and air is removed, operator turns off the valve and pump will start developing pressure in valve.

I am thinking to attach air bleed valve (once air is remoived bleed valve will close due to its designing feature) there but don't know if whether it will work or not. if you have any other option to bleed the air from the system then suggestion is widely accepted.

For valve, which is needed to be partially open/closed according to API 598 during testing, for that I have assumed that when valve will come from assembly line to testing line it will be kept in partially open/closed position by assembly men.

 

[Danlap]

Hi Bharti,

There are multiple post from you for the last two days and it is not really clear whether you are manufacturer(+tester) or tester only or..? And if you are manufacturer, is the assembly facility within the same building with your testing facility?
Transferring valve from one division to another e.g. ball valve ideally done whilst valve in open position. For two main reason: 1) if ball valve transferred without end caps/protector (which is a normal practice for internal transfer), potential debris or relatively sharp object may 'fall' and damage the ball. 2) simply a habit/practice, if valve set at open (or sometimes close) it is easier to install handle, positioner.
If there is no robust protocol, assume the worst condition that it will be in close position and without end caps. By any means, operator need to intervene to half open the valve and close/open again.

Air bleed valve might work, but whether it is effective or not it might requires extra research. Air pocket or bubble depending on valve internal design complexity requires time to travel upwards.
Since API 598 always mentioned in your post, I assume your company is aiming to do the test in relatively fast time of 15 seconds to 6 minutes per valve prototype and the same. Assuming you are also aiming for filling is less than 10 minutes (which is quite fast for valve larger than 8"). Will the remaining bubble(s) completely "bleeded" within 16 minutes and not causing false reading? No body knows, but I am guessing for some cases bubbles will remain shall no manual intervention applied.
Suggest to do empirical analysis. Try with multiple type and various sizes of valve, even if API 598 table remains suggest to develop your own standardize "table" time required to develop pressure to be complemented as extra protocol.
Since this is not hyperbaric or cyrogenic testing bench and also not an airplane cockpit, suggest to make the interface as simple as possible. Or with clear protocol.

Kind regards,
MR

https://nosuchvalve.com

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected

http://www.eng-tips.com/faqs.cfm?&rat1=2&fid=376

 

[Bharti__]

@danlap,

I am working on a project for a manufacturing firm, for which i am searching and designing different setups and recently i have found about this forums so you may find my different doubts together in relatively short time (May be i will share more doubts so you may find too many doubts together in line on forum in future) and yes i am trying to design this testing facility with assembly line.

I am focusing on valve size of only 1/4" - 2" so filling time is too much less than you have mentiond and yes i am trying to do this test as fast as possible thats why i am avoiding this kind of manual movements.

So, thank you for your suggestion, i will rethink on valve opening and closing position during assembly and testing and also will plan to make my standardised table to test valves considering all standards.

Thank you.



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