Need Help! Top Entry Cryogenic Butterfly Valve(-170 degree centigrade) 1

[LarryChang]

One of our clients ask for "Top Entry Cryogenic Butterfly Vale"
1)DN150, Class 900LB, Top Entry, BW ends SCH120S, Gear Operated.
2)For Cryogenic services at -170°C, Main Material: CF3M
But our engineer insist that it is impossible to make the "Top Entry" type cause the pressure is too high. And he suggested me recommand top entry ball valve to our client as substitute.

I wonder whether the top entry type is an appropriate design for 900LB butterfly valve in -170°C services?

Thank you very much in advance!!

Larry Chang
Larry@carilovalve.com

 

[LarryChang]

Would anyone please kindly give me some advice? It's urgent!

 

[PAN]

Larry,

You're a valve manufacturer. Should you look for advice from others in your specific product design?

 

[LarryChang]

Well, Pan. Although we are a valve manufacturer, we can't find the relevant design standard to follow. And I searched other manufacturer's products catalogue and consulted some engineers, but can't find a solution. And our clients insist on the "top entry" type and the products should be cryogenic tested with DNV witness as per BS6364.

Larry

 

[ione]

Regards

http://www.kdesign24.de/pdf/linde_cryogenic.pdf

 

[gerhardl]

Ditto.

....its wonderful what Google can do for you.

http://www.amrivalves.com/danais.html

 

[bcd]

Look at the MAPAG catalog. They make top entry butterfly valve for cryogenics. So do other manufacturers.

 

[HitokiriAoshi]

While this may deviate from OP, what are the advantages to a top entry butterfly?

 

[ione]

On line maintenance can be carried out without the need of dismantling the valve.

 

[TOVmania]

For the Top Entry Type Triple offset Class #900, you coul only rely on probably 4 manufacturers with confidence. Top entry is definitely applicable because it is there for maintanance purpose.

 

[PAN]

Difficult to say...Who are the said 4 manufacturers?

Each manufacturer would like to sell his product...

 

[NGiLuzzu]

In my opinion the required valve may be feasible... but is not for sure the best solution! ;-)

Basically, the first advantage of triple-offset design, if compared with ball or gate valves of the same rating class and size, is space and weight saving (with similar or better tightness and flow capability, and lesser maintenance requirements).
Of course, this is not true in each and every case: for example, a ND 3" / class 900 triple-offset disc would not be much different (in weight, dimensions and shape) from the ball valve obturator for the same pipe size and pressure (and most likely the open ball valve Cv would be higher...).

The top-entry feature, in addition, does not make things simpler…: also in this case, one should think about the meaning and the scope of the design solution under exam (in this case: providing a maintenance entry while minimizing the number of possible leakage sources like flanges) and wonder whether the game is worth the candle (how large must the top entry port be to make components easily accessible? How often is maintenance actually needed? How much does that cost if compared with a new valve? How much possible leakage is avoided? )…


I do understand that I’m talking about switching the brain on and thinking, which is one of the most difficult things to obtain from Customer Specifications (and Marketing & Sales Guys, sometimes…)… but just let me be optimistic for one time

Hope this helps,
‘NGL
________________________

 

[jeffvalve]

I'd like to see somebody attempt to change the seat inline on a 6" 900# TOV with top entry. I did it some years back on some 12" 600# Top entry TOV's and that was difficult enough. what happens if one of the seat retainer bolts shears in the disc. Try getting a drill and stud extractor into the 6" body!! I just don't think the valve would be a viable option in this size. Talk you customer into using a gate or ball valve in this case.

JV