Hollow and Solid Balls
Hollow and Solid Balls
(OP)
Hi All,
Our supplier just informed us, they are going to use solid ball for a 2" floater and a hollow ball for a 3" floater.
will there be any difference in performance?
what is the reason they use hollow balls in some cases and solid in some?
Thanks in advance
Our supplier just informed us, they are going to use solid ball for a 2" floater and a hollow ball for a 3" floater.
will there be any difference in performance?
what is the reason they use hollow balls in some cases and solid in some?
Thanks in advance





RE: Hollow and Solid Balls
I guess an analogy that might fit is engineered wooden I-Beams. When these first came on the market, builders shunned them in favor of dimensional lumber. Over time the clear benefit of the I-beam became obvious and you rarely see a floor system in a home made from dimensional lumber today. My guess is that the hollow balls would be the same thing.
David
RE: Hollow and Solid Balls
RE: Hollow and Solid Balls
If you were to manufacture a hollow ball, the assumption of a low stress state may no longer hold and we could start to see sour cracking where none had been seen before.
Myself, before I would accept a hollow ball, I'd want to ensure that the cost savings were being passed onto me and until there was some experience with them, I'd be a little wary of potentially unintended consequences as described above.
Also, I wonder about the fire safety of the hollow ball? I'd want to ensure that the valve was fully tested under the current API 607 fire test standard.
RE: Hollow and Solid Balls
That is the kind of thing I meant when I said "If the manufacturer got all his sums right". There are probably a hundred important issues over and above what you or I could think of in a few minutes. If the manufacturer satisfied all the codes and is passing real cost savings on to the purchaser, then the valves will start to show up in parts houses. Some people will buy them and a history will start to build up. If there are no issues in the next 40-50 years then they'll "suddenly" be mainstream. Industries using ball valves are not exactly quick to adopt innovation.
David
RE: Hollow and Solid Balls
Heather Smith
My interests: Alloy valves, duplex valves, super duplex valves, 6Moly valves, inconel valves, incoloy valves, alloy 20 valves and titanium valves.
RE: Hollow and Solid Balls
All parties are so far correct in my opinion, exept that the hollow ballvalve actually exists, and for cost reasons and weight reasons only: small awith exotic and/or highcost material or larger also with more common material with weight reasons in addition to cost.
If you commercially can buy a solid ball at equal, or slightly different pricelevel I would go for the solid ball.
If the pricelevel are lower for the hollow ball, or the difference totals to a larger sum, I would as stated above check references, certifications and qualifications for the manufacturer of hollow ball and ask for long-term references for the actual applications, to ensure troublefree performance and also analyze cost/lifetime consequences of using the hollow ball.
Some years ago I supplied a series of hollow ball constructed ball-valves for fairly large ballvalves and higher pressure classes with welded on exotic material overlay on the ball, for offshore use.
This total fabrication process is highly technically demanding, and a limited number of suppliers are able to supply certified top quality.
The end user was fully satisfied with price and performance and bought several times for similar processes over a number of years .
RE: Hollow and Solid Balls
Clause 4.7 of this standard prohibits the use of hollow balls unless specifically agreed to by the purchaser.
I also found a reference elsewhere that said the use of hollow ball valves promotes turbulence and reduces CV factors although I find this strange. I have never seen a hollow ball though so I can't really comment one way or the other on that point.
RE: Hollow and Solid Balls
That being said, the losses in ball valves are usually too low to notice, and it's a rarity that a hollow ball is damaged in service. A hollow ball is less expensive just becaouse there is less metal involved, and in larger sizes it will contribute to better seat life because its lighter weight reduces eccentric weight-related seat loading.
RE: Hollow and Solid Balls
Hello Jim,
Seems that we perhaps differ in definition of 'hollow ball'.
Your definition seems to be directly sphereformed shell with a two holes 180 deg apart giving the full opening in and out.
I have seen this construction only as part of this 'shell' with a V-port opening to regulate the flow, a 'V-port ballvalve'
I have, on the other side, seen constructions for larger ballvalves where the througlet of the hollow ball is a pipe (full opening) welded into the spheric shell, giving same flow as for a solid ball.
I would, as always, appreciate your comments.
RE: Hollow and Solid Balls
Both types are probably available somewhere ...
RE: Hollow and Solid Balls
50-70% lighter than conventional solid balls.
20-40% decrease in seating/unseating torque.
Reduce weight, saving on shipping.
Reduced weight also help's reduce risk of damage to soft seats during assembly.
I had never heard of these before, apparently popular on smaller sizes (up to 2 1/2") and #300.
Attached sectional drawing of hollow ball.
Ciao,