CR4 - The Engineer's Place for News and Discussion ®


Previous in Forum: Standard Codes for Laundry Exhaust Air Changes   Next in Forum: Carbon Steel Pipeline Internal Coating
Close
Close
Close
12 comments
Associate

Join Date: Oct 2007
Location: Belgrade, Serbia
Posts: 52
Good Answers: 1

Monoflange Slimline vs. Floating Ball

07/08/2017 4:31 AM

Hi all,

The client is concerned that our proposed slimline monoflange DBB valve on crude oil line shall be prone to clogging due to debris in crude, and asking to check the possibility of installing the floating ball valve instead. Alas, the PO is already placed, we have to justify our choice of slimline. Vendor is saying it's almost the same in terms of clogging risk.

Any thoughts?

Thanks in advance!

__________________
cheerz
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Guru
Australia - Member - New Member

Join Date: Feb 2008
Location: Australia
Posts: 1714
Good Answers: 200
#1

Re: Monoflange slimline vs. floating ball

07/08/2017 5:07 AM

Your vendor has asked a question and you seem to now have the answers. Communicate with them. "The vendor indicates almost same clogging risk." and "Order is already placed." Determine cost to your organisation to make the change and let them know. They will then decide.

__________________
Just an Engineer from the land down under.
Register to Reply
Associate

Join Date: Oct 2007
Location: Belgrade, Serbia
Posts: 52
Good Answers: 1
#2
In reply to #1

Re: Monoflange slimline vs. floating ball

07/08/2017 6:07 AM

Any suggestions about how to justify slimline instead of floating ball?

As per our experience it is actually same, just as the vendor says. However additional experience is always valuable.

__________________
cheerz
Register to Reply
Power-User

Join Date: Dec 2016
Posts: 202
Good Answers: 4
#3

Re: Monoflange slimline vs. floating ball

07/08/2017 8:26 AM

Is it a cost vs performance question?

__________________
formally known as texasron
Register to Reply
Associate

Join Date: Oct 2007
Location: Belgrade, Serbia
Posts: 52
Good Answers: 1
#6
In reply to #3

Re: Monoflange slimline vs. floating ball

07/09/2017 3:40 AM

No, the valves have already been purchased, however the client wants to change them now. We wouldn't mind that much, it's only 4 valves, but the vendor is saying from their experience that it's actually not an advantage in this case. And obviously, we wouldn't want to prolong the delivery time if not really to advantage.

__________________
cheerz
Register to Reply
Guru
New Zealand - Member - Kiwi Popular Science - Weaponology - New Member Engineering Fields - Power Engineering - New Member Engineering Fields - Electrical Engineering - New Member

Join Date: Sep 2006
Location: Auckland, New Zealand
Posts: 8318
Good Answers: 342
#8
In reply to #6

Re: Monoflange slimline vs. floating ball

07/09/2017 4:43 PM

Pass the supplier's comments regarding the suitability of the offered valves on to the customer as well as including any price differences and lead times (both standard and priority service delivery) for the alternative valves the customer wishes and let them make up their minds.

Alternatively cancel the order, order the alternative valves and work with the customer regarding delivery time and perhaps price adjustment. This option will likely result in you not making as much profit but may be worth it to keep the customer happy.

Did you place the purchase order before the order was approved and signed off by the customer? If so your options may be limited.

__________________
jack of all trades
Register to Reply
2
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 17938
Good Answers: 1028
#4

Re: Monoflange Slimline vs. Floating Ball

07/08/2017 11:31 AM

Unless you have a compelling reason not to, give the customer what they want....or somebody else will....

http://www.eng-tips.com/viewthread.cfm?qid=355092

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply Good Answer (Score 2)
Participant

Join Date: Jul 2017
Posts: 1
#5

Re: Monoflange Slimline vs. Floating Ball

07/08/2017 11:13 PM

Monoflange vs globe "butterfly" valves indeed collect debris given crude quality-velocity-pressure and total surface contact. Ball valves present less surface, flow resistance, overall longer life (maintenance) however the customer already appears to agree with that premise so why on earth would anyone propose a losing position? Sealing Proves better/easier/accurate in ball configuration too!

Register to Reply
2
Power-User

Join Date: Jul 2016
Posts: 332
Good Answers: 17
#7

Re: Monoflange Slimline vs. Floating Ball

07/09/2017 2:09 PM

The description, slimline DBB is not very descriptive, I see confusion about butterfly globe valves, which is nonsense, and we might assume DBB is double block & bleed, which does not describe trim at all, and monoflange might be related to butterfly valve construction. Maybe mono-block.

Ball valves with floating ball, or maybe you mean floating trim on a ball valve.

In any event, it is going to be difficult to get anyone with experience to give you some insight if they have no idea what you are talking about...

Register to Reply Good Answer (Score 2)
Associate

Join Date: Oct 2007
Location: Belgrade, Serbia
Posts: 52
Good Answers: 1
#9
In reply to #7

Re: Monoflange Slimline vs. Floating Ball

07/10/2017 3:16 AM

Well, Solar Eagle has an idea, in fact, pretty good idea that is. Be like Solar Eagle.

Anyhow, its about double block and bleed monoflange valve for connection of the instruments to the flowline, slimline is needle valve, floating ball is ball valve construction of DBB arrangement. Hope it's clearer now.

__________________
cheerz
Register to Reply
2
Power-User

Join Date: Jul 2016
Posts: 332
Good Answers: 17
#10
In reply to #9

Re: Monoflange Slimline vs. Floating Ball

07/10/2017 8:53 AM

Yes, much clearer. This application is for instrument impulse lines (very small lines), so there is normally not any flow, except if the line is being charged, and that is very low flow. If installed properly, little chance of debris or contamination that could foul the valve workings ever reaching the seat.

In heavy industry, the custom with potentially dirty fluids is to install 50mm or 1/2" valves and piping/tubing. That is sufficient in most cases to pass contamination, usually iron pipe scale. Use of smaller size, 3/8" or 1/4" results in considerable fouling potential, from experience. Needle valves are normal on this type of equipment. A non-standard ball valve installation will probably get replaced with much more common needle valve manifold during the first maintenance operation on that equipment.

The risk of contamination, pipe scale is normal, is much higher in the dirt legs that the valve manifold is connected to. Periodic flushing of the dirt leg is somewhat important, depending on the contamination source.

Needle valves are operated full open or full closed, so the valve design has little relevance to the plugging potential. In addition, with my 20+ years in heavy industry instrumentation, I have never come across a needle valve manifold that did not shut off leak free, even 30 year old equipment. I can't say that about any sort of ball valve, Teflon or metal seated.

Register to Reply Good Answer (Score 2)
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 11091
Good Answers: 131
#11
In reply to #10

Re: Monoflange Slimline vs. Floating Ball

07/10/2017 2:19 PM

Yes, the only problem there is if they cannot install the instruments correctly, and they leak (at first).

Give the customer (who is always right) what they requisitioned in the first place, then move along, nothing to see here.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Associate

Join Date: Oct 2007
Location: Belgrade, Serbia
Posts: 52
Good Answers: 1
#12
In reply to #10

Re: Monoflange Slimline vs. Floating Ball

07/15/2017 1:21 AM

Thanks rwilliams, much appreciated!

__________________
cheerz
Register to Reply
Register to Reply 12 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Copy to Clipboard

Users who posted comments:

Drhall (1); drift (4); jack of all trades (1); James Stewart (1); Just an Engineer (1); ronc (1); rwilliams (2); SolarEagle (1)

Previous in Forum: Standard Codes for Laundry Exhaust Air Changes   Next in Forum: Carbon Steel Pipeline Internal Coating

Advertisement