GB1603814A

GB1603814A - Closure for pipes or vessels

Info

Publication number: GB1603814A
Application number: GB3410677A
Authority: GB
Original assignee: SWINNEY ENG
Current assignee: SWINNEY ENG
Priority date: 1977-08-15
Filing date: 1977-08-15
Publication date: 1981-12-02

Description

(54) IMPROVED CLOSURE FOR PIPES OR VESSELS (71) We, SWINNEY ENGINEERING LIMITED, a British Company, of Morpeth, Northumberland, NE6 11 HR, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to an improved closure for pipes or vessels and to a safety assembly for closures for pipes or vessels.

In our prior British Patent Specification No.

1181757 there is disclosed a closure for an opening in a pressure pipe or vessel adapted to co-operate with a circular groove or bead around the opening, the closure comprising a circular cover, an angularly displaceable member pivoted at the centre of the cover, and at least two arcuate locking members positioned around the periphery of the cover, each locking member being linked at one end to the angularly displaceable member and pivoted at the other end of the cover adjacent to the periphery of the cover, so that in operation when the closure is fitted to the container and the angularly displaceable member tumed in the required direction relative to the cover, the locking members move into engagement with the groove or bead thereby locking the closure in position.

The present invention is preferably an additional safety feature for a closure of the type described in our prior British Patent No. 1181 757 but may be incorporated on any other suitable closure.

The invention provides additional safety features to protect operating personnel as much as possible against incorrect and dangerous operating procedures when working with pipes and vessels which may be at a pressure above atmospheric.

According to the present invention there is provided a closure for closing an opening in a pipe or vessel having a locking groove or bead on the inside of the opening the closure comprising at least one locking member at the periphery of the closure, an angularly displaceable member operative to engage the or each locking member with the groove or bead to lock the closure to the pipe or vessel and a releasable bridge member for interconnection between the closure and the pipe or vessel arranged so that initially on disengagement of the or each locking member, the closure can only be partially opened into a position in which the bridge member may be released to allow the closure to be completely opened.

Preferably the bridge member is secured to one of the closure or the pipe or vessel and has three operational positions; a first position in which the closure is closed and in which the bridge member cannot be released from said position to allow opening of the closure, a second position in which the closure is partially open and in which the bridge member cannot be released from said position to allow opening of the closure, and a third position different from the first and second positions in which the bridge member may be released to allow the closure to be fully opened. The bridge member therefore prevents the closure being fully opened for example by pressure within a pipe or vessel thus protecting operating personnel from injury.

Preferably the closure of the invention also includes a safety vent which is operably connected with the angular displaceable member to prevent release of the closure until the safety vent is opened. The angularly displaceable member is suitably an elongate handle and preferably the handle includes a safety bar arranged to prevent the handle being moved to a closed position without the safety vent first being engaged.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a sectional side elevation of a closure in a closed position; Figure 2 is a sectional side elevation of a closure in a partially open position; Figure 3 is a sectional side elevation of a closure in the release position; Figure 4 is a sectional side elevation of a closure being closed.

Figure 5 is a sectional view of a first embodiment of safety vent to be incorporated in a closure in accordance with the present invention; Figure 6 is a sectional view of a second embodiment of safety vent in the open position but with residual pressure in pipe or vessel; Figure 7 is a sectional view of the embodiment of Figure 6 with the safety vent in the closed position; Figure 8 is a side elevation of a similar embodiment to the embodiment shown in Figure 5 showing an additional safety modification in the closed position and from which the releasable bridge member has been omitted for clarity; Figure 8a is a view on Arrow A in Figure 8; Figure 9 is a side elevation of the arrangement in Figure 8 showing the additional safety modification in the open position with the releasable bridge member omitted; and Figure 9a is a view on arrow A in Figure 9.

In Figures 1 to 4 of the drawings a closure 1 has locking pieces 2 for locking the closure 1 in the opening 3 of a pipe or vessel 4. The locking pieces 2 are operable to lock the closure 1 in position on angular movement of a handle 5 to which the locking pieces 2 are connected. For a more particular description of this aspect of the closure 1 reference is directed to our prior British Patent Specification No. 1,181,757. The closure 1 and the pipe or vessel 4 also includes various seals of known type generally indicated 6.

The bridge member 7 of the present invention is seen at the bottom of Figures 1 to 4 and comprises an elongate plate 8 having a downwardly inclined leading edge 9. One end of the plate 8 is secured to the closure 1 by a bolt 10 having a spring 11 between its head 21 and the plate 8 so as to allow the plate 8 to pivot relative to the axis of the bolt 10 as indicated by dotted lines 12 in Figure 3. Intermediate the ends of the plate 8 there is an opening 13 which engages with the head 14 of a bolt 15.

In the closed position of the closure 1 as shown in Figure 1 the plate 8 is prevented from pivotal movement for release by engagement of the head 14 of the bolt 15 with a rear edge 22 of the opening 13. Figure 2 illustrates a partially open position of the closure 1 in which the plate 8 is similarly prevented from pivotal movement for release by engagement of the bolt 15 with the opposed forward edge 23 of the opening 13.

Release of the plate 8 is effected at a position intermediate the limit positions shown in Figures 1 and 2 and can be seen from Figure 3 in which the dotted lines 12 indicate the pivotal release of the plate 8. In this way if an excess pressure exists behind the closure, on opening, the closure will only be flung between the limits shown in Figures 1 and 2 preventing serious injury to an operator.

Figure 4 illustrates the closure 1 being shut, the inclined leading edge 9 automatically causing the plate 8 to latch with the bolt head 14 so that the bridge member 7 is always in operative position when the closure 1 is shut.

The bridge member 7 may be in plate form as disclosed or may be of any other suitable form for example the bridge member may be a rod or strut.

Although not shown in Figures 1 to 4 a safety vent interlock may also be provided as afurther safety feature preventing angular movement of the handle and various embodiments in this respect are illustrated in Figures 5 to 9.

In the first embodiment of safety vent shown in Figure 5 the closure 1 has a handle 152 and a safety vent 153 normally screwed into the position shown. The safety vent 153 is linked with the handle 152 by a locking plate 154 which, in the position shown, prevents angular movement of the handle 152.

The safety vent 153 has a central passage 155 extending substantially from midway of the vent plug to the outer end. At the outer end there is a clear dome 156 which retains a moving flow indicator 157 for a visible warning and gas escape holes 158 for an audible warning.

Extending from the inner end of the safety vent 153 is a second passage 159 which, in the closed position of the vent, is separated and sealed from the central passage 155 by a 'Dowty' seal 160.

The locking plate 154 has a key-hole slot 111 wider at the bottom thereby providing a shoulder 112 which normally rests on the outside of the larger diameter portion of the vent 153. On release of the vent plug 153 a portion of smaller diameter is aligned with the plate 154 so that the locking plate 154 moves or may be moved away from the handle 152 to allow the handle to be operated. However the release of the safety vent plug 153 causes the seal 160 to be broken so that the central passage 155 and the second passage 159 come into fluid communication.

If a pressure exists in the pipe or vessel a visible and audible warning will be given so that the operator will not open the closure until the warnings have ceased i.e. until the pressure is atmospheric. The fluid in the pipe or vessel may be liquid or gas or any combination thereof.

Figures 6 and 7 illustrate an alternative embodiment of safety vent actually preventing release of the handle until pressure within the pipe or vessel is vented. In this embodiment the audible and visible warnings may be incorporated as well but this has not been illustrated. In the second embodiment the closure 121 has a handle 122 and a vent plug 123. The handle 122 and vent plug 123 are interlocked, in the closed position, by a locking member 124. As with the previous embodiment the vent plug 12:- has a central passage 125 and a second passage 126 is formed between the plug and the closure body, the two passages being separated in the closed position by a seal 127. However in addition the vent plug 123 has a piston member 128 fixed thereto and a movable cylinder 129 surrounding the body of the vent plug 123. The cylinder 129 is movable along the body of the vent plug 123 between the piston 128 and a fixed flange 130 on the plug 123 by a spring biassed plunger 131.

The locking member 124 has an abutment edge 132 which in the closed position shown in Figure 7 rests on the top of the piston 128 preventing release of the handle 122. The locking member 124 also has an extension portion 133 having a key-hole slot 134. The shape of the key-hole slot 134 is such that in the position shown in Figure 6 the shoulder 135 rests on the body of the cylinder 129 but, on movement of the cylinder 129 towards the left in Figure 6 the locking member 124 is able to slide down between the fixed flange 130 and the cylinder 129 about the smaller diameter of the plug body thereby allowing release of the handle 122.

In operation on release of the vent plug 123 the seal 127 is broken and the passages 125 and 126 brought into fluid communication. Vent holes 136 pass from the central passage 125 to between the piston 126 and cylinder 129 so that, in the event of pressure within the pipe or vessel the cylinder 129 is forced against the fixed flange 130 until the pressure has been released - see the position shown in Figure 6. Until the pressure has been released the cylinder 129 cannot be pushed to the left by the plunger 131 so that the locking member 124 is prevented from movement to release the handle 122 by engagement of the abutment shoulder 135 with the body of the cylinder 129.When there is no residual pressure in the pipe or vessel the cylinder 129 may be moved to the left in Figure 6 by the plunger 131 allowing the locking member 124 to slide downwardly between the cylinder and the flange 130 and thereby release the handle 122.

It is understood that in a vertical disposition the cylinder may be arranged to return by gravity preventing the necessity of plunger 131.

Also the fact that cylinder 129 is moved outwardly against the flange 130 provides a visible waming of a pressure within the pipe or vessel.

In Figures 8, 8a and 9, 9a which show a modification to a similar embodiment to Figure 5, the handle 152 is angularly movable about a central hub 140 to open and close the closure 1.

The safety vent 153 is shown with its associated locking plate 154 engaging the handle 152. The modification comprises a bar 141 which is pivoted from the central hub 140 by a hinge pin 142 and is guided through a guide 143 to prevent the handle 152 being engaged without the safety vent 153 being operated. To open the closure from the position shown in Figure 8 safety vent 153 is unscrewed and the locking plate 154 is moved out of engagement with the handle 152 i.e. to the right in Figure 8a. The handle 152 is then moved to the open position and the bar 141 moves to the release position indicated in Figures 9 and 9a. On closing the closure handle 152 the bar 141 will prevent complete closure unless the safety vent 153 has been released from preventing complete angular movement of the handle 152 into the engaged position. The safety vent 153 is then replaced.This acts as an additional safety measure preventing the closure being shut without the safety vent being operated.

Although not illustrated in Figures 5 to 9 it will be understood that the closure also includes the door restraining mechanism disclosed in Figures 1 to 4 of this application.

WHAT WE CLAIM IS: 1. A closure for closing an opening in a pipe or vessel having a locking groove or bead on the inside of the opening the closure comprising at least one locking member at the periphery of the closure, an angularly displaceable member operative to engage the or each locking member with the groove or bead to lock the closure to the pipe or vessel and a releasable bridge member for interconnection between the closure and the pipe or vessel arranged so that initially, on disengagement of the or each locking member, the closure can only be partially opened into a position in which the bridge member may be released to allow the closure to be completely opened.

2. A closure according to Claim 1, wherein the bridge member is secured to one of the closure or the pipe or vessel and has three operational positions; a first position in which the closure is closed and in which the bridge member cannot be released from said position to allow opening of the closure, a second position in which the closure is partially open and in which the bridge member cannot be released from said position to allow complete opening of the closure, and a third position different from the first and second positions in which the bridge member may be released to allow the closure to be fully opened.

3. A closure according to Claim 2, wherein the bridge member is elongate and is secured to the closure at one end by a bolt and a spring is included between the head of the bolt and the bridge member to allow the bridge member to pivot relative to the axis of the bolt.

4. A closure according to Claim 3, wherein the bridge member includes an opening which in use engages a projection on the pipe or vessel to prevent complete release of the closure without pivotal movement of the bridge member.

5. A closure according to Claim 4, wherein the projection is a bolt having a head which in the first position of the bridge member engages a rear edge of the opening preventing pivotal movement of the bridge member.

6. A closure according to Claim 4, wherein in the second position of the bridge member the head of the bolt engages a forward edge of the opening preventing pivotal movement of the bridge member.

7. A closure according to Claim 4, wherein the third position of the bridge member is intermediate the first and second positions and allows the head of the bolt to pass through the opening so that the bridge member may be pivoted to effect release thereof and thereby allow complete opening of the closure.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

The locking member 124 has an abutment edge 132 which in the closed position shown in Figure 7 rests on the top of the piston 128 preventing release of the handle 122. The locking member 124 also has an extension portion 133 having a key-hole slot 134. The shape of the key-hole slot 134 is such that in the position shown in Figure 6 the shoulder 135 rests on the body of the cylinder 129 but, on movement of the cylinder 129 towards the left in Figure 6 the locking member 124 is able to slide down between the fixed flange 130 and the cylinder 129 about the smaller diameter of the plug body thereby allowing release of the handle 122.

In operation on release of the vent plug 123 the seal 127 is broken and the passages 125 and

126 brought into fluid communication. Vent holes 136 pass from the central passage 125 to between the piston 126 and cylinder 129 so that, in the event of pressure within the pipe or vessel the cylinder 129 is forced against the fixed flange 130 until the pressure has been released - see the position shown in Figure 6. Until the pressure has been released the cylinder 129 cannot be pushed to the left by the plunger 131 so that the locking member 124 is prevented from movement to release the handle 122 by engagement of the abutment shoulder 135 with the body of the cylinder 129.When there is no residual pressure in the pipe or vessel the cylinder 129 may be moved to the left in Figure 6 by the plunger 131 allowing the locking member 124 to slide downwardly between the cylinder and the flange 130 and thereby release the handle 122.

It is understood that in a vertical disposition the cylinder may be arranged to return by gravity preventing the necessity of plunger 131.

Also the fact that cylinder 129 is moved outwardly against the flange 130 provides a visible waming of a pressure within the pipe or vessel.

In Figures 8, 8a and 9, 9a which show a modification to a similar embodiment to Figure 5, the handle 152 is angularly movable about a central hub 140 to open and close the closure 1.

The safety vent 153 is shown with its associated locking plate 154 engaging the handle 152. The modification comprises a bar 141 which is pivoted from the central hub 140 by a hinge pin 142 and is guided through a guide 143 to prevent the handle 152 being engaged without the safety vent 153 being operated. To open the closure from the position shown in Figure 8 safety vent 153 is unscrewed and the locking plate 154 is moved out of engagement with the handle 152 i.e. to the right in Figure 8a. The handle 152 is then moved to the open position and the bar 141 moves to the release position indicated in Figures 9 and 9a. On closing the closure handle 152 the bar 141 will prevent complete closure unless the safety vent 153 has been released from preventing complete angular movement of the handle 152 into the engaged position. The safety vent 153 is then replaced.This acts as an additional safety measure preventing the closure being shut without the safety vent being operated.

Although not illustrated in Figures 5 to 9 it will be understood that the closure also includes the door restraining mechanism disclosed in Figures 1 to 4 of this application.

WHAT WE CLAIM IS: 1. A closure for closing an opening in a pipe or vessel having a locking groove or bead on the inside of the opening the closure comprising at least one locking member at the periphery of the closure, an angularly displaceable member operative to engage the or each locking member with the groove or bead to lock the closure to the pipe or vessel and a releasable bridge member for interconnection between the closure and the pipe or vessel arranged so that initially, on disengagement of the or each locking member, the closure can only be partially opened into a position in which the bridge member may be released to allow the closure to be completely opened.
2. A closure according to Claim 1, wherein the bridge member is secured to one of the closure or the pipe or vessel and has three operational positions; a first position in which the closure is closed and in which the bridge member cannot be released from said position to allow opening of the closure, a second position in which the closure is partially open and in which the bridge member cannot be released from said position to allow complete opening of the closure, and a third position different from the first and second positions in which the bridge member may be released to allow the closure to be fully opened.
3. A closure according to Claim 2, wherein the bridge member is elongate and is secured to the closure at one end by a bolt and a spring is included between the head of the bolt and the bridge member to allow the bridge member to pivot relative to the axis of the bolt.
4. A closure according to Claim 3, wherein the bridge member includes an opening which in use engages a projection on the pipe or vessel to prevent complete release of the closure without pivotal movement of the bridge member.
5. A closure according to Claim 4, wherein the projection is a bolt having a head which in the first position of the bridge member engages a rear edge of the opening preventing pivotal movement of the bridge member.
6. A closure according to Claim 4, wherein in the second position of the bridge member the head of the bolt engages a forward edge of the opening preventing pivotal movement of the bridge member.
7. A closure according to Claim 4, wherein the third position of the bridge member is intermediate the first and second positions and allows the head of the bolt to pass through the opening so that the bridge member may be pivoted to effect release thereof and thereby allow complete opening of the closure.
8. A closure according to any one of Claims

4 to 7, wherein the bridge member has an inclined leading edge causing the bridge member to latch with the projection on the pipe or vessel automatically thereby ensuring that the bridge member is always in the operative position when the closure is shut.
9. A closure according to any one of the preceding Claims including a safety vent which is operably connected with the angularly displaceable member to prevent release of the closure until the safety vent is opened.
10. A closure according to Claim 9, wherein the safety vent includes a pressure-operated interlock which on release of the safety vent continues to prevent the angularly displaceable member being released until there is little or no residual pressure within the pipe or vessel.
11. A closure according to Claim 9 or 10, wherein the safety vent includes visible and/or audible means indicating the escape of pressure from within the pipe or vessel.
12. A closure according to any one of Claims 9 to 11, wherein the angularly displaceable member is an elongate handle, and the handle and the safety vent are operably connected by a locking plate, the safety vent having two surface portions engageable with a keyhole slot in the locking plate, one surface portion having a larger diameter than the other surface portion so that in the closed position the surface portion of larger diameter is in engagement with the locking plate preventing movement thereof but when the safety vent is released the other surface portion is brought into engagement with the locking plate and is able to pass into a smaller part of the keyhole slot enabling the locking plate to be moved away from the handle allowing release thereof.
13. A closure according to any one of Claims 9 to 12, wherein the safety vent comprises a first passage from the interior of the pressure pipe or vessel to a position intermediate the ends of the vent, a second passage in the vent in com- munication with the exterior of the pressure pipe or vessel, and sealing means operative to seal the two passages from one another when the vent is closed and to open communication between the two passageways when the vent is released.
14. A closure according to Claim 13 as dependent upon any Claim dependent upon Claim 10, wherein the pressure-operated interlock comprises a piston fixedly secured to the safety vent and a movable cylinder slidably received on the safety vent, the second passage being in communication with the piston and cylinder arrangement so that, in the event of pressure within the pipe or vessel, the angularly displaceable member is prevented from release until the pressure has been released through a clearance between the piston and the cylinder.
15. A closure according to any one of the preceding Claims 9 to 14, wherein the angular displaceable member is an elongate handle and the handle includes a safety bar arranged to prevent the handle being moved to a closed position without the safety vent first being engaged.
16. A closure for closing an opening in a pressure pipe or vessel substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.