Rotary ball valve assembly
A method of forming a ball valve element for a rotary ball valve assembly, the method comprising the steps of: (a) inserting an impedance element through an insertion opening of a ball valve element into a bore; (b) forming a fluid opening in the ball valve element which is non-rectilinearly aligned with the insertion opening and which communicates with the bore; and (c) sealing the insertion opening. A ball valve element for a rotary ball valve assembly formed using such a method; and a rotary ball valve assembly comprising a ball valve element formed using such a method are also provided.
1. A method of forming a ball valve element for a rotary ball valve assembly, the method comprising the steps of:
a) inserting an impedance element through an insertion opening of a ball valve element into a bore;
b) forming a fluid opening in the ball valve element which is non-rectilinearly aligned with the insertion opening and which communicates with the bore; and
c) sealing the insertion opening.
2. A method as claimed in claim 1 , wherein the fluid opening is defined by a plurality of first apertures.
3. A method as claimed in claim 2 , wherein the first apertures are circular and/or non-circular.
4. A method as claimed in claim 1 , wherein, in step (a), the insertion opening is formed in the ball valve element.
5. A method as claimed in claim 1 , wherein the insertion opening is a first pre-formed opening, and the ball valve element includes a second pre-formed opening which communicates with the bore, and which is non-rectilinearly aligned with the first pre-formed opening.
6. A method as claimed in claim 1 , further comprising a step (d) subsequent to step (b) of forming a second fluid opening in the ball valve element which communicates with the bore and which is non-rectilinearly aligned with the insertion opening.
7. A method as claimed in claim 6 , wherein the second fluid opening is defined by a plurality of second apertures.
8. A method as claimed in claim 7 , wherein the second apertures are circular and/or non-circular.
9. A method as claimed in claim 1 , wherein the impedance element is plate shaped, and the said insertion opening includes a slot in which the impedance element is slidably receivable.
10. A method as claimed in claim 1 , wherein the impedance element is formed from a plurality of plates stacked vertically or horizontally.
11. A method as claimed in claim 1 , wherein the impedance element extends across the lateral extent of the bore.
12. A method as claimed in claim 1 , wherein the impedance element only partially extends across the lateral extent of the bore.
13. A method as claimed in claim 1 , wherein the impedance element fully obstructs the bore.
14. A method as claimed in claim 1 , wherein the impedance element only partially obstructs the bore.
15. A method as claimed in claim 1 , wherein steps (a), (b) and (c) are performed in an order of (a), (b), (c) or (b), (a), (c).
16. A ball valve element formed using a method as claimed in claim 1 .
17. A rotary ball valve assembly comprising a ball valve element formed using a method as claimed in claim 1 .