WALL THICKNESS FOR BALL VALVE

[ALEXANDRAHARPER]

HI,

i NEED YOUR HELP IN ORDER TO KNOW THE WALL THICKNESS FOR A BALL VALVE, I ALREADY BOUGHT SOME VALVES AND THE SUPPLIER MADE THE ULTRASONIC TEST REPORTS BUT I HAVE SOME DOUBT ABOUT IT, AND I NEED TO KNOW HOW CANI KNOW THE WALL THICKNESS FOR THE SIZE AND RAITING OF A VALVE.

REGARDS.

 

[caihui]

please refere ANSI B16.34 or BS5351. You can found the data

 

[ALEXANDRAHARPER]

HI I ALREADY HAVE THE ASME B16.34 IN MY HANDS BUT I'M NOT PRETTY SURE HOW TO USE IT BECUASE I NEED TO HAVE THE INSIDE DIAMETER OF THE BALL VALVE, BUT I DON'T KNOW WHICH ONE IS. FOR EXAMPLE COULD YOU LET ME KNOW THE MINIMUM WALL THICKNESS FOR A 30" BALL VALVE?

 

[BigInch]

There isn't a minimum thickness (that I know of), as that depends on the material used to construct the valve, the method of construction, forged, cast, etc. configuration and pattern, and the valve's pressure rating. A high strength alloy would need much less wall thickness than a mild steel or cast iron.

You should specify the minimum inside diameter required and that it should be a full bore valve to your specified .D.

http://virtualpipeline.spaces.msn.com

 

[proinwv2]

In such a large valve, I would also ask whether any external loads would need to be considered in the body design. (I have no experience in such sizes).

Have you inquired of the manufacturer as to their methodology for determining minimum wall? For instance, codes, pressure and temperature, or factor of safety.

Paul Ostand

http://www.ostand.com

 

[ALEXANDRAHARPER]

I HAVE ASKED TO MY SUPPLIER THE MINIMUM AND MAXIMUM WALL THICKNESS FOR THE VALVES THAT HE ALREADY SOLD TO ME BUT HE DON'T WANT TO DO IT.

THE BRAND OF THE VALVES IS SCV SOUTHERN CALIFORNIA VALVES.
I DON'T KNOW HOW TO PUSH HIM TO DO IT.

I HAVE REQUESTED THE WALL THICKNESS TO MY SUPPLIER BECUASE ANOTHER COMPANY MADE THE ULTRASONIC TEST FOR THE WELDING OF THE VALVES, I WANT TO VERIFY IF THE RESULTS OF THE ULTRASONIC COMPANY MATCHES THE MEASURES OF MY SUPPLIER

 

[BigInch]

I'm not exactly sure why you want to verify something your testing company measured for you by asking the equipment manufacturer again, when they already told you they don't want to confirm, but I suppose you have your reasons.

Just withhold 10% of the payment until they cough up the appropriate documents. Until then believe your testing company.

http://virtualpipeline.spaces.msn.com

 

[proinwv2]

It seems strange that the manufacturer is taking this position. It makes one wonder why?

You might go at it this way. Share your findings with them, and request a statement that these findings are within their design parameters.

Learn from this on how to specify on future orders.

Paul Ostand

http://www.ostand.com

 

[vpl]

[small]By the way, it's not necessary to shout. The lower case function works fine in these forums.[/small]

Patricia Lougheed

Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.

Want to post an image? Look at the FAQ's in forum559

 

[ovlvalves]

Hi Alexandra,
ANSI B16.34 is a good guide to ensuring the wall thickness of the pressure vessel (in your case a ball valve).
What is the valve size you have bought, the material of construction (i.e. CF8M, LCC, 316, LF2 etc) and the pressure rating.
ANSI B16.34 table 3 allows you to calculate the min wall thickness of a vessel but again you must account for other factors, e.g. Corrosion allowances, service conditions and process.
Volumetric NDE (UT) is a good method of checking the wall thickness and so is RT (Radiography).
As a high pressure valve manufacturer (

http://www.valves.co.uk),

we would have no objections to this information as product must be designed and manufactured to code. A valve manufacturer should be able to provide wall thickness evidence, unless it is coming from a stockist and therefore does not have this information.
Hope this helps