Ball type valve having improved redundant sealing system

An improved ball-type valve apparatus adapted for use in flowlines which provide a straight through flow path which minimizes flow turbulance and flow resistance in either direction through the valve housing. The ball is rotated by a crank between the open and closed positions for controlling flow through the valve. Oppositely facing seat rings engage the ball on opposite sides to provide a dual redundant sealing system with the primary seals located at the upstream seat with the secondary seal formed at the downstream seat. An access plug retains the ball in the valve housing and is secured with the valve housing by a segmented locking ring. When the plug is removed from the housing maintenance or assembly access to the ball, seat rings and their retaining means without disturbing the connections of the valve housing in the flowlines is provided.

TECHNICAL FIELD 
This invention relates to the field of vavles for controlling flow of fluid 
in a conduit. In particular, the invention relates to an improved quick 
operating valve for use in flowlines that may be repaired in place without 
disturbing the flowline connections. 
BACKGROUND ART 
Quick acting valves using ball-type closure elements are well known. 
Examples of such quick response ball-type valves are disclosed in the 
following U.S. Pat. Nos. that are assigned to the assignee of the present 
invention: 
2,734,715 
2,863,629 
2,883,146 
3,035,808 
3,036,590 
3,064,938 
3,509,913 
3,589,667 
While the disclosed valves have achieved numerous improvements and 
advantages, they, along with the other valves they exemplify, have had 
several limitations or drawbacks. Such limitations have related primarily 
to a number of features or combinations thereof and have primarily 
included lack of easy access to the internal components of the valve for 
maintenance purposes, redundant closure sealing of the flow and the 
capability to control flow in either direction through the valve with 
equal assurance. 
SUMMARY OF THE INVENTION 
A new and improved valve apparatus having a quick acting rotatable 
ball-type flow closure element disposed between a pair of seats for 
controlling flow through the valve in either direction is provided. A 
removable seal plug provides easy access to the central cavity of the 
valve housing for maintenance of the ball and seats without disturbing the 
connection of the valve in the flowline. Redundant sealing with the ball 
element is achieved by a pair of movable seat rings that are disposed in 
the valve housing to provide a straight through flow path free of flow 
restrictions. Spring biased retainers constantly urge the seats in sealing 
contact with the ball with the upstream seat providing the primary seal 
and the downstream seat providing the secondary seat. A mounting flange is 
formed on the valve housing for mounting an actuator or operator mechanism 
for rotating the valve crank to operate the valve.

BEST MODE FOR CARRYING OUT THE INVENTION 
The improved valve apparatus A of the present invention having enhanced 
access for maintenance or assembly operations is illustrated in the FIGURE 
in a manner to emphasize the arrangement for assembly. As will be 
explained the valve apparatus A is connectable in a flowline for 
controlling fluid flow in the usual manner. 
The valve apparatus includes a hollow valve casing or housing 10 having a 
central cavity 12 formed therein. The housing 10 forms at one end an inlet 
opening 14 for receiving flow in the cavity 12 and at the opposite end of 
said housing an outlet opening 16 for exhausting the flow of fluid 
received in the cavity 12. The cavity 12 provides a central flow path 
through the housing 10 along a defined longitudinal axis on which both 
openings 14 and 16 are disposed and which provides a straight through flow 
passage for minimizing flow turbulence and resistance. While the end 
openings 14 and 16 are described as inlet and outlet openings, 
respectively, it is understood that the valve apparatus A of the present 
invention may be used to control flow in either direction through the 
housing 10. Suitable means such as mounting flanges 18 and 20 are provided 
for connecting the apparatus A in a flow conduit (not illustrated) with 
inlet and outlet openings 14 and 16 communicating with the conduit for 
providing the passage for the flow of the fluid. The flanges 18 and 20 are 
provided with the circumferentially spaced bolt openings for enabling the 
passage of securing bolts therethrough in the usual manner. 
The cavity 12 has an enlarged central portion 12a which operably receives a 
substantial spherical flow closure element or ball-type valve 22 therein. 
The ball 22 is formed with an outer spherical sealing surface 22a and a 
longitudinal central flow passage 22b extending therethrough. The ball 22 
is rotatable between an open position in which the flow passage 22b is 
aligned with the longitudinal axis of the cavity 12 to provide an 
unrestricted flow passage through the valve 10 and a closed position with 
the flow passage 22b disposed traverse to the longitudinal axis of the 
cavity 12 for blocking flow of fluid through the valve housing 10 between 
the inlet 14 and outlet 16. The central flow passage is also enlarged 
adjacent the central cavity 12a at 12b and 12c for receiving a pair of 
identical valve seats 24 and 26 disposed concentrically upon the 
longitudinal axis of the central flow path for reciprocating movement into 
engagement with the centrally positioned ball 22. The seats 24 and 26 are 
disposed on opposite sides of the ball 22 for sealingly engagement 
therewith with arcuate sealing surfaces 24a and 26a in the usual manner. A 
pair of O-rings 28 and 30 are carried by the outer surface of the seat 
rings 24 and 26 for effecting a seal between the seat rings 24 and 26 and 
the valve housing 10 in the usual manner. The seals effected by the 
O-rings 28 and 30 are on a less diameter about the longitudinal axis than 
that established by the arcuate sealing surfaces 24a and 26a with the ball 
22 in order to provide a pressure responsive urging on the seat rings 24 
and 26 for pressure energizing them into greater sealing contact with the 
ball 22 to assist sealing at high pressure. 
The seats 24 and 26 are maintained or limited against reciprocating 
movement away from the ball 22 by identical seat retainers 33 and 34, 
respectively, that engage the enlarged annular collars 24b and 26b of the 
seat rings 24 and 26, respectively. The seat retainer 33 is identical in 
construction to the retainer 34, but is reversed in position when 
assembled in the valve 10. For this reason only one seat retainer 34 needs 
to be described in greater detail. The retainer 34 forms a one ended slot 
34a for receiving or mounting over the collar 26b of the seat ring 26. A 
rounded support surface 34b is disposed on one side of the retainer 34 for 
engaging the valve housing 10 to hold the retainer 34 in position in order 
that the recess 34a of the central opening will be properly positioned for 
operably locating the seat ring 26. The opposite substantially flat face, 
34c, is provided with vertical ribs 34d and 34e on opposite sides of slot 
34a and having longitudinally extending openings 34f and 34g formed the 
length of the ribs 34d and 34e. The ribs 34d and 34e are formed with a 
plurality of spaced interruptions along their lengths to provide access to 
openings 34f and 34g. The rib openings 34f and 34g receive spring mounting 
pins 36 and 38 having eccentric lobe sections 36a and 38a formed thereon, 
respectively for positioning in the rib interruption. A pair of identical 
spring retainer pins 40 and 42 are received in the retainer 33 in a 
similar manner in order that a plurality of eight springs, four of which 
are illustrated and referenced as 44 in the FIGURE, may be connected at 
the spaced locations on the pins 36, 38, 40 and 42. The springs 44 are 
disposed exteriorly of the ball 22 and serve to urge or maintain the seat 
rings 24 and 26 in sealing engagement with the ball 22. The eccentric cam 
lobes 36a, 38a, 40a and 42a formed on the spring retainer pins enable the 
springs 44 to be properly tensioned after placing the ball 22 between the 
seats 24 and 26 by rotation of the pins from above with a screwdriver 
after assembly in the housing 10 as will become more apparent. 
The ball 22 is provided with an upwardly facing slot 22c formed in the 
upper flat surface 22d. A coupling disk 46 is provided with a downwardly 
facing rib 46a which engages the slot 22c for rotating the ball 22 in 
response to rotation of the disk 46. It being understood that the groove 
or slot could be formed on the disk 46 and the lug or rib on the ball 22 
with equal ease while performing the same function. The coupling disk 46 
is also provided with an upwardly facing slot 46b that receives a 
downwardly facing lug 50a formed on the upwardly extending rotatable crank 
or stem 50. The stem 50 forms an annular collar 50b which engages a thrust 
ring 52 for holding the stem or crank 50 in rotatable engagement with the 
coupler disk 46 and the ball 22 in the usual manner while preventing 
longitudinal movement from the housing 10 in a manner to be more fully 
described. 
The housing 10 has a maintenance or assembly access opening 10a formed 
therein through which the ball 22, seats 24 and 26 and the retainers 32 
and 34, along with springs 44, may be installed or removed. The circular 
opening 10a forms an annular recess 10b in the housing for receiving a 
quick acting segmented locking ring 56. The locking ring 56 serves to 
secure a central plug 58 carrying an external seal 60 in the opening 10a 
for sealing with the housing 10 to block leakage of fluid between the plug 
58 and the housing 10. A central opening 58a of the plug 58 provides 
mounting clearance for the rotatable crank 50 in the usual manner while a 
pair of internal O-rings 62 seal between the rotatable crank 50 and the 
plug 58. The plug 50 also mounts the thrust bearing 52 which holds the 
crank 50 within the valve housing 10 while permitting its rotational 
movement. The plug 58 is releasably secured with the housing 10 by first 
installing the outer two segments 56a and 56b of the locking ring 56 in 
the annular groove 10b followed by the central portions 56c and 56d. The 
reverse sequence may be used to enable removal of the locking ring 56 
components from the groove 10b which permits removal of the plug 58 and 
provides maintenance access through the opening 10a to the ball 22 and the 
seats 24 and 26 without disturbing the connection of the flange 
connections 18 and 20 with the flowline. To maintain the locking segments 
56a, 56b, 56c and 56d in the annular recess or groove 10b, a retaining 
ring 64 is employed while a spiral retainer ring 66 is expanded in an 
annular slot (not illustrated) is used to hold the ring 64 in position. A 
mounting flange 10d disposed about the opening 10a provides a means 
whereby an actuator or operator for the valve apparatus A may be attached 
in the usual manner to provide for remote operation of the valve apparatus 
A. 
Operation of the Present Invention 
In the use and operation of the valve opponents A of the present invention, 
the valve housing 10 is mounted in a flowline using flanges 18 and 20 in 
the usual manner. It being understood that other end connections may also 
be employed to mount the valve housing 10 in the flowline without 
departing from the spirit of the present invention. Prior to connection of 
the housing 10 in the flowline the valve, apparatus A may be assembled in 
the manner indicated but if not, the valve internals can be assembled in 
the following sequence: the seat 26 and retainer 34 may be installed in 
the cavity 12 through the opening 10a and placed adjacent the outlet 
opening 16. The seat ring 24 and the retainer 32 are then moved through 
the opening 10a into the cavity 12 where they are positioned adjacent the 
inlet opening 14. In this regard it should be noted that the inlet opening 
14 and the outlet opening 16 are provided with enlarged portions 14a and 
16a adjacent the cavity 12 for receiving the seats 24 and 26 in order that 
they may reciprocate through a small range of movement along the 
longitudinal axis of the central flow path. The ball 22 is then installed 
and springs 44 attached to the retainer pins 36, 38, 40 and 42. 
Alternately, the springs 44 may be attached before inserting the ball 22 
between the retainer 32 and 34. After the springs 44 are installed, the 
spring retainer pins 36, 38, 40 and 42 may be rotated in order that the 
eccentric lugs thereon 36a, 38a, 40a and 42a, respectively, will tension 
the springs 44 for holding the seats 24 and 26 in sealing engagement with 
the ball 22. 
The coupler disk 46 is then placed in engagement with the ball 22 in order 
that the groove 46a will engage the slot 22c of the ball and the stem 50 
is then positioned in similar engagement with the coupler disk 46. The 
thrust ring 52 is placed over the collar 50b and the plug 58 with O-rings 
60 and 62 moved into the opening 10a for effecting its closure. With the 
plug 58 in sealing position in opening 10a, the segments 56a, 56b, 56c and 
56d of the split lock ring are located in the annular groove 10b and 
secured thereto by the installation of the retaining ring 64 and 66. 
Manual means such as a handle may then be attached to the crank 50 for 
rotating the quick acting or closing ball element 22 to and from the open 
and closed positions as is known in the art. If desired, a valve actuator 
may be attached to the mounting flange 10d for effecting remote control 
rotation of the ball 22 by rotating the crank 50 in the usual manner. 
When it becomes necessary to maintain the A, valve access can be obtained 
to any of the internal component parts through opening 10a by reversing 
the sequence of assembly. 
In operation the valve apparatus A provides a dual redundant sealing system 
for the straight through flow passage. The primary flow passage seals are 
provided at the upstream seal interface of the seat 24 and ball 22 and the 
upstream seat 24 and body 10 seal provided by the O-ring 28. The resultant 
forces due to the shut-in upstream pressure are transmitted through the 
ball 22 to the downstream seat 24 and the retainer 34 where they are 
transmitted into the housing 10. This arrangement also provides a pressure 
differential across the ball 22 and the upstream seat 24 which loads the 
seal therebetween in response to the differential pressure thereacross and 
assures a superior seal at elevated shut-in pressures. If the primary 
upstream seat fails, sealing is accomplished at the downstream seat 26 and 
ball 22 interface and the downstream seat 26 and body 10 interfaced by the 
seal 30. This is accomplished by the contained fluid pressure on the ball 
22 urging it against the seat 26 which is held by the retainer 34. It is 
understood that either seat 24 may serve as either the downstream seat or 
the upstream seat without affecting the operation of the valve apparatus A 
of the present invention as the symmetrical arrangement of the ball 22 and 
seats 24 and 26 permit pressurizing the valve in either direction with 
equal shut-off performance. The preloading contact between the ball 22 and 
seats 24 and 26 established by the force of the springs 44 provides a 
wiping action on the ball 22 as it rotates for preventing the entrance of 
foreign particles into the sealing interface. 
The foregoing disclosure and description of the invention are illustrative 
and explanatory thereof, and various changes in the size, shape, and 
materials, as well as in the details of the illustrated construction, may 
be made without departing from the spirit of the invention.