Safety closure member

A safety closure for use in a flange in which the flange has an internal circumferential groove in the passageway therethrough, the closure being formed of a cylindrical body slidably receivable within the flange passageway, the body having a reduced diameter opening therethrough, a plurality of leaves slideably supported to the body, the outer ends of the leaf being receivable in the flange groove, an elastomeric gasket to seal the periphery of the body to the flange passageway, and a pressure relief member slidably received in the body passageway, the upper end of the pressure relief member being of enlarged diameter and received between opposed inner ends of the leaves when the leaves are outwardly positioned within the flange groove to thereby prevent the leaves from being removed from the groove, the pressure relief member being downwardly displaceable to an open position permitting fluid flow through the cylindrical body prior to permitting the leaf to be retracted thereby assuring release of pressure before the leaves can be moved to the position permitting the closure member to be removed from the interior of the flange.

SUMMARY OF THE INVENTION 
The use of a flange to close piping connected to high internal pressure is 
well known. Further, the concept of a removeable plug to close the 
interior of a flange is also a common expedient. For reference to prior 
art relating to this subject, the following U.S. patents are applicable: 
U.S. Pat. Nos. 278,670, 822,562, 3,070,129, 3,125,123, 3,155,116, 
3,449,860, 4,178,967, 4,188,675, 4,360,290, 4,387,740 and 4,466,550. 
The most relevant known prior art to the present invention are five patents 
assigned to T. D. Williamson, Inc. of Tulsa, Oklahoma as follows: VerNooy 
U.S. Pat. No. 3,155,116, Osburn U.S. Pat. No. 3,766,947; Rankin U.S. Pat. 
No. 4,058,142; VanZamt U.S. Pat. No. 4,387,740; and Sullivan U.S. Pat. No. 
4,466,550. Each of these prior issued patents disclose closure members 
which are adaptable to close the passageway through a flange and including 
means for removing the closure when necessary. The present invention 
relates to an improvement in the basic concept disclosed in these prior 
art patents and particularly relates to improved safety features. One of 
the safety problems concerned with the use of closure members in flanges 
is that it is very hazardous to release a closure member from confinement 
within the interior of a flange when the closure member is under pressure. 
When such occurs, the closure member can be forced out of the flange at 
great speed and can cause injury to the operators and damage to equipment 
used for removing the closure member. Another problem is that it is 
extremely important for the operator to know that the closure member is in 
securely locked position before pressure is permitted to accumulate below 
the closure member. 
The present invention provides a closure member for flanges which has 
several advantages including the following (1) The flange itself includes 
no moving parts, that is all the moving parts are confined within the 
closure member. (2) The possibility of leakage of the flange is prevented 
since no holes, O-rings, hardware and so forth are required on the outside 
of the flange. (3) The closure member includes a relief mechanism which 
keeps the closure member locked (that is, prevents it from being unlocked) 
without the bypass opening through the closure member being first opened. 
(4) The action of opening or closing the pressure relief of the closure 
member is distinct and separate from the action of locking or unlocking 
the closure member. (5) The closure member of this invention is adaptable 
to a variety of alternate flange designs. 
The closure member is formed of a cylindrical body of external diameter 
which can be slidably received within the passageway through a flange. The 
flange must be of the type having an internal circumferential groove and 
preferably also has an internal circumferential ledge below the groove. 
The closure member cylindrical body has a reduced diameter passageway 
through it. 
A plurality of leaves are slidably supported to the cylindrical body. Each 
leaf has an outer end and an inner end and each leaf is slidable between 
an outward and inward position. The outer ends of the leaves are 
receivable in the flange groove when the leaves are slidably utwardly 
extended to thereby retain the cylindrical body in the flange passageway. 
The cylindrical body has a circumferential groove on it below the leaves 
and an elastomeric gasket is received in the groove and provides means to 
seal the passageway when the cylindrical body is in position in the 
flange. 
A pressure relief member is slidably received in the cylindrical body 
passageway. The pressure relief member has an internal opening through it 
and has an enlarged diameter upper end and an enlarged diameter lower end. 
The pressure relief member is upwardly biased by a spring. The enlarged 
diameter upper end is receivable between opposed inner ends of the leaves 
when the leaves are in their outward positions, but the pressure relief 
member is prevented from moving upwardly when the leaves are in the inward 
positions because of the overlap of the inner ends of the leaves. A seal 
is provided in the relief member so that when it is in the upward position 
flow of fluid through the reduced diameter opening is prevented. 
To install the closure member it is positioned within a flange. The leaves 
are utwardly extended so that the outer ends extend within the interior 
circumferential groove within the flange. This permits the relief member 
to be moved upwardly by spring compressive force to seal the passageway 
through the cylindrical member. This upward movement of the relief member 
also prohibits the leaves from being internally retracted, thus, 
preventing the inadvertent removal of the closure member. To remove the 
closure member, the relief member must be first downwardly depressed, 
providing fluid flow through the relief member to thereby relieve pressure 
fromthe interior of the closure member and to equalize pressure across the 
closure member. Thereafter, the leaves may be withdrawn, permitting the 
closure member to be removed from within the flange. 
A better understanding of the invention will be had by reference to the 
following description and claims taken in conjunction with the attached 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings and first to FIG. 1 a pipeline is shown in 
cross-sectional view and identified by the numeral 10. A flange 12 is 
attached to pipeline 10 by a short tubular member 14. While the invention 
may be used in a variety of ways a typical application is one in which, 
after the pipeline 10 is in use, it is determined that an opening needs to 
be provided in the pipeline and the opening must be provided without 
taking the pipeline out of service, that is without depressurizing or 
draining the pipeline. To accomplish this the tubular member 14 is welded 
to the exterior of the pipeline and flange 12 welded to it. A tapping 
machine, generally indicated by the numeral 16, is affixed to the flange. 
The tapping machine includes a valve generally indicated by the numeral 
18. By a mechanism not shown the tapping machine can extend a cutter 
through flange 12 and tubular member 14 to cut a hole 20 in the wall of 
the pipeline 10. Thereafter the cuttingtool may b withdrawn and a pipe or 
other apparatus communicating with the interior of the pipeline 10 may be 
attached, the valve 18 being opened and closed as necessary during the 
procedure to prevent the interior of the pipeline from being exposed to 
the environment and thereby prevent leakage of fluid or gases from the 
pipeline. This procedure is a well known technique employed in the 
industry. After communication is established with the pipeline, such as, 
for instance, to by-pass a portion of the pipeline, such as, for instance, 
to by-pass a portion of the pipeline, it is desirable to close off the 
passageway 22 extending through the flange 12 with a closure member, after 
which the tapping machine 16, including the valve portion 18, may be 
removed. Such closure member needs to be removeable so that if desired in 
the future, access can again be reestablished with the interior of 
pipeline 10. It is an improved closure member to which the present 
invention is applied. FIG. 1 shows a closure member generally indicated by 
the numeral 24 as in position for being inserted outwardly through the 
valve 18 into the interior of flange 12. 
Referring to FIGS. 2 through 7, a preferred embodiment of the improved 
closure member of the present invention is shown. 
The closure member is formed of a cylindrical body 26 having an external 
cylindrical surface 28 of diameter to be slidably received within the 
flange. The configuration of the cylindrical surface 28 preferably 
includes an enlarged diameter lip portion 30 which sits on a ledge 32 
formed in the interior of the flange passageway 22. By the provision of 
lip 30 and ledge 32, when the closure member is inserted into the 
flange,it is automatically properly positioned relative to the flange. 
Flange 12 includes an internal circumferential groove 34 positioned above 
the ledge 32. 
The cylindrical body 26 has a plurality (three are shown in the illustrated 
embodiment) of radially extending T-shaped grooves 36. The cylindrical 
body 26 is further defined by a circumferential groove 38 which receives 
an elastomeric seal 40. When the closure member 24 is positioned within 
flange 12 the seal 40 compresses against the interior sidewall of 
passageway 22, thereby closing the passageway. 
Formed within the cylindrical body 26 is a reduced diameter pressure relief 
passageway 42 which preferably includes an internal ledge 44 and an 
increased internal diameter upper portion 46. 
Affixed to the top surface 26A of the cylindrical body are a plurality 
(three being shown in the illustrated embodiment) of leaves 48. Each of 
the leaves has an outer end 48A and an inner end 48B. Each leaf has, 
extending integrally from its underneath surface, a T-shaped portion 50 
which is slidably received in one of the T-shaped grooves 36. Thus, the 
leaves 48 are reciprocally extendable in a radial direction relative to 
the closure member. 
Extending upwardly from the upper surface of each leaf is a pin 52 which is 
used for extending or retracting the leaves in a manner to be described 
subsequently. 
Received in the pressure relief passageway 42 is a pressure relief member 
54 which may be, as illustrated, in the form of a bolt having a head 56 at 
the lower end and an enlarged diameter portion 58 threaded on the upper 
end. The portion 58 is receivable in the increased internal diameter 
recess 46 formed in the cylindrical body when the pressure relief member 
is in the downward position as shown in FIG. 3. The spring 60 is 
compressibly positioned between the ledge 44 and the enlarged diameter 
portion 58 to constantly urge the pressure relief member 54 in the upward 
direction. 
Fluid bypass openings are provided in the pressure relief member, best 
shown in FIG. 6. The central opening 62 extends from the upper end of the 
member to adjacent the head portion 56. Lateral openings 64A and 64B 
communicate with the central opening 62. Further, the enlarged diameter 
head portion 58 has openings 66. Positioned on the pressure relief member 
54 is a washer 68 having an integral elastomeric seal 70. When the 
pressure relief member 54 is in the upward position the pressure relief 
passageway 42 is closed, but when the pressure relief member is in the 
downward position, as shown in FIGS. 3 and 6, fluid can freely flow 
through the passageway 42, thereby permitting pressure to be equalized to 
either side of the closure member. 
FIGS. 6 and 7, along with FIG. 1, show a means of inserting and removing 
the closure member from the interior of a flange. The attachment mechanism 
is generally indicated by numeral 72 and is of a type commonly employed in 
industry and not a direct part of the invention and therefore will not be 
described in detail except for a flange plate 74 illustrated in FIGS. 8 
and 9. The flange plate has a central hexagonal opening 76 and curved 
slots 78, there being one slot for each of the leaves 48. the slots 78 are 
dimensioned to receive the ends 52 extending upwardly from the leaves. 
When the came plate 74 is positioned in engagement with the closure 
members so that ends 52 are received within slot 78, the rotation of the 
cam plate serves tomove the leaves radially inwardly and outwardly. 
The attachment mechanism 72 includes a downwardly extending plunger, the 
lower end 80 of which is hexagonal and is slidably received in the 
hexagonal opening 76 in the flange plate. 
To install a closure member 24 within flange 12, referring to FIG. 1, the 
valve 18 is open as shown. the closure member 24 is lowered by tool 16 to 
the interior of flange 12. The closure member seats properly within the 
interior of the flange when lip 30 rests against ledge 32 as shown in FIG. 
5. To secure the closure member within the flange, the plunger is rotated, 
the lower end 80 of which rotates the cam plate 74 to radially outwardly 
extend leaves 48. As the outer end 48A of the leaves extends within groove 
34 within the flange, it can be seen that the flange is securely locked in 
position. Further, it can be seen that the seal 40 closes flange 
passageway 22. It should still further be observed that when the closure 
member is inserted with the leaves withdrawn, the pressure relief member 
54 must be downwardly depressed to the position shown in FIGS. 2 and 3 
thereby permitting fluid to flow through the pressure relief member to 
equalize pressure on each side of the closure member. After the leaves 
have been outwardly extended and the plunger 80 upwardly withdrawn, spring 
60 move the pressure relief member to the upper position as shown in FIGS. 
5 and 7. This serves two functions. First, it closes fluid flow through 
the reduced diameter passageway 42. Second, the enlarged upper end portion 
58 of the pressure relief member prohibits the leaves 48 from being 
inwardly withdrawn, that is, moved out of engagement with the flange 
groove 34. The passageway through the flange is now completely sealed and 
the closure member is locked in position. This will enable the operator to 
completely remove the tapping machine 16 and the valve 18 if desired and a 
blind flange could then be bolted on the flange. 
Later, if it is desired to again provide entry into the interior of the 
pipeline 10, the operator can remove the blind flange (not shown) if it is 
affixed to flange 12. Thereafter, the valve 18 and the tapping machine 
mechanism 16 is attached. To remove the closure member 24, the operating 
mechanism isfirst lowered and before effort can be made to remove the 
closure member, the plunger 80 must be downwardly positioned. This moves 
the pressure release member 54 downwardly to provide fluid communication 
through the passageways in the pressure relief member so that pressure can 
be quickly equalized to either side of the closure member. Thereafter, as 
a separate and distinctive step, the plunger is rotated, rotating the cam 
plate to retract the leaves. Note that the leaves can not be retracted 
until the pressure relief member is first downwardly positioned to insure 
that pressure is equalized to either side of the closure member. This 
action which requires two separate and distinct actions of the operator 
insures that the closure member can not be released from engagement within 
the interior of the flange without first the operator intentionally taking 
the step necessary to relieve the pressure across the closure member. 
The invention is shown utilizing three leaves 48 although obviously four or 
mroe may be employed. While only two leaves may be used, a preferred 
arrangement contemplates at least three such leaves. 
FIGS. 10 and 11 shown an alternate embodiment of the invention in which the 
closure member 24 has a circumferential groove 82 therein and wherein each 
of the leaves is formed to two basic portions, that in a crescent shaped 
segment portion 84 and a linkage member 86. Each linkage member is 
received in a radially extending opening 88. 
In the illustrated arrangement each of the radial openings 88 is 
cylindrical in cross-section and each of the linkage members 86 is 
likewise of generally cylindrical cross-sectional configuration and is 
slideable within the openings 88. 
Each of the segment portions 84 has an outr frustocircular edge 84A which 
is of about the diameter of the outer cylindrical surface of the internal 
circumferential groove 34 in flange 12 and the segment portions 84 are 
inwardly and outwardly slideable within the circumferential groove 82. The 
outer end of each of the linkage members 86 is affixed to a segment 
portion 84 such as by means of a pin 90 which is received in an opening 92 
in each of the segments. 
Affixed to each of the linkage members 86 adjacent the inner end thereof is 
an upstanding pin 52A which has the same purpose as pin 52 of the leaves 
previously described; that is, the pins 52A are received in slots 78 of a 
cam plate 74. When the cam plate is rotated in one direction the linkage 
members 86 are moved inwardly, thereby moving the segments 84 inwardly and 
when the cam plate is rotated in the opposite direction the linkage member 
and therefore the segments are pushed outwardly. In the outward direction, 
as illustrated in FIGS. 10 and 11, the segments extend within the internal 
groove 34 of flange 12. It can be seen that the embodiment of Figure 10 
and 11 functions essentially the same as that of the first described 
embodiment except that the leaves are arranged differently. 
The pressure relief member 54A of FIG. 10 functions in the same manner as 
that of the pressure relief member previously described with a slight 
exception in the method of sealing. A circumferential groove 94 is formed 
in the pressure relief member 54A adjacent the bottom thereof and receives 
an O-ring 96. In the upward, closed position, the O-ring is received 
within the pressure relief passageway 42 to close fluid flow through it. 
In addition, in this upward position the enlarged diameter portion 58 
prevents the linkage members 86 from being moved inwardly, thereby 
preventing the lcosure member 24 from being inadvertently removed from the 
flange until the pressure relief member 54A has been downwardly displaced. 
The passageways 62, 64A and 64B provide a channel so that when the 
pressure relief member is downwardly displaced communication is provided 
to relieve pressure differential whichmay exist across the closure member. 
This assures that the closure member of FIGS. 10 and 11 is provided with 
the safety feature the same as that described for the first embodiment. In 
FIGS. 10 and 11 a circular recess 98 is formed in the top surface of the 
plug member body 26 which receives the cam plate 74 but otherwise the 
operation of the cam plate remains the same. 
While the invention has been described with a certain degree of 
particularity it is manifest that many changes may be made in the details 
of construction and the arrangement of components without departing from 
the spirit and scope of this disclosure. It is understood that the 
invention is not limited to the embodiments set forth herein for purposes 
of exemplification, but is to be limited only by the scope of the attached 
claim or claims, including the full range of equivalency to which each 
element thereof is entitled.