17 replies to this topic

[farid.k]

Hye team.

May i know what type of valve body can be used as ESD valve? Is it gate or butterfly is acceptable? Or ball? Any special requirements?

[Bobby Strain]

The type you select may depend on the SIL level required. I would choose one that will close with a spring on air failure.

 

Bobby

[Saml]

In chemical/petrochemical what I have seen installed are globe (same as a normal control valve), ball valves and butterfly (specially the triple offset type) for ESD.

[fallah]

farid,

 

As an ESDV should have following characteristics:

 

-Quick action from full open to full closed

-Tight shut off (near zero leakage)

-On/Off action (not throttling)

 

It should mostly be Ball Type...

[farid.k]

Thanks bobby.

But what if my project don't have sil study? It is just a methanol storage facility and loading facility. They just conduct HAZOP

[farid.k]

I agree to use ball.  But what if they want to go for butterfly. They claim butterfly is cheaper.

[fallah]

 

farid,

 

Butterfly might be cheaper but cannot be produced as tight shut off and also will generate more delta P than ball type...

[breizh]

hi farid.k

 

Here we are talking Safety /Emergency and isolation , definitely Butterfly valve is not an option.

 

For sure Butterfly valve is cheaper !

 

my view .

Breizh

Edited by breizh, 02 June 2017 - 04:21 AM.

[Mahdi1980]

Farid,

 

I agree with Fallah, since butterfly valve most of the time has leakage and cannot be tight shut off. So, it might not be reliable as an ESDV.

Please note that the size of the valve is also important. The maximum applicable size of ball valves is 8 inches. If it is higher, a tight shut off butterfly valve to be used which is more expensive.

Anyhow, for the sizes of 1 to 8 inches Ball valve is the best choice.

[fallah]

 

Mahdi,

 

I think what you mentioned for maximum allowable size, as 8", is applicable for globe valve not for ball valve. Hence, there is no size limitation, at least till 24", for using ball valve as ESDV...

[farid.k]

Thanks fallah and all

How about sil study that has been mentioned by Bobby? What if my project just has HAZOP? basically my project is just involve methanol storage and loading facility. Does that require SIL? Or ball valve already considered worst case?

[breizh]

Hi ,

About valves may be good to have a look .

 

Hope this is going to help you and others

Breizh

[fallah]

Thanks fallah and all

How about sil study that has been mentioned by Bobby? What if my project just has HAZOP? basically my project is just involve methanol storage and loading facility. Does that require SIL? Or ball valve already considered worst case?

 

If it's intended the SIL study to be done in mentioned plant, the valve as final element of a loop containing sensor, controller and valve shall have the required SIL according to the loop's SIL requirement and the ball type valve will provide the proper conditions such as leakage rate and tightness based on which the SIL study will be conducted for a valve...

[farid.k]

Hi ,
About valves may be good to have a look .

Hope this is going to help you and others
Breizh

Thanks so much sir

[farid.k]

Thanks fallah and all

How about sil study that has been mentioned by Bobby? What if my project just has HAZOP? basically my project is just involve methanol storage and loading facility. Does that require SIL? Or ball valve already considered worst case?

If it's intended the SIL study to be done in mentioned plant, the valve as final element of a loop containing sensor, controller and valve shall have the required SIL according to the loop's SIL requirement and the ball type valve will provide the proper conditions such as leakage rate and tightness based on which the SIL study will be conducted for a valve...

Thanks fallah

[vigneshdk]

Hello all,
I was listening to the discussion. Thanks to all esteemed seniors engineers​ for taking time and answering questions. I was also reading about water hammer due to sudden valve closure. Which may be related to Emergency safety discharge valves. I have a question (not related to an actual operations case) in relation to this so I can improve my understanding. when an esdv is suddenly opened using a ball valve and then closed until partial discharge What would be the water hammer effects expected and are there any design methods to minimise hammer effects in this case?
Thanks in advance for taking time to discuss this.
Regards
Vignesh

[farid.k]

Hello all,
I was listening to the discussion. Thanks to all esteemed seniors engineers​ for taking time and answering questions. I was also reading about water hammer due to sudden valve closure. Which may be related to Emergency safety discharge valves. I have a question (not related to an actual operations case) in relation to this so I can improve my understanding. when an esdv is suddenly opened using a ball valve and then closed until partial discharge What would be the water hammer effects expected and are there any design methods to minimise hammer effects in this case?
Thanks in advance for taking time to discuss this.
Regards
Vignesh

To properly calculate the closure time for minimising the impact
To consider adequate support to avoid vibration

[ankur2061]

Dear All,

 

I was under the same impression that Butterfly valves cannot be used for Emergency Shutdown application. But this is no longer true that butterfly valves cannot be used. Nowadays you get zero-leakage triple off-set butterfly valves from renowned suppliers such as Emerson-Vanessa, Velan & L&T which can be used in ESD service.

 

Further references are provide below as links:

 

http://www.processin...utterfly-valves

 

https://www.velan.co...alves.html/1/53

 

http://www.vanessava...fset_design.php

 

http://www.lntvalves...iple-offset.pdf

 

in fact in one of the current projects we are working on, a pipeline ESD valve has been specified as a triple off-set butterfly valve.

 

Regards,

Ankur.

Edited by ankur2061, 05 July 2017 - 01:17 AM.