GB2175885A - Purging of fluid from sealing arrangement - Google Patents

Abstract

A lid to container body sealing arrangement comprises a pair of laterally spaced sealing members 10, 12 which are compressed between the lid 16 and container body 18 to define an endless passage 20. This passage 20 is provided with a port 22 so that leak testing can be carried out. Water trapped in the passage 20 when the lid is fitted under water has to be removed before leak testing is carried out but known methods of doing this are slow and unreliable. An improved method comprises pumping a gas into the passage 20 via a pipe 24, which extends through the port 22, and has a lateral opening 32 so that a circulatory flow is set up around the passage 20. The water-carrying gas exits through a gap 34 between the pipe 24 and port 22. <IMAGE>

Description

SPECIFICATION Purging of fluid from sealing arrangements This invention relates to the purging of fluid, especially water from a sealing arrangement between the lid and body of a container.

In a known container design, there is provided a lid to body sealing arrangement comprising a pair of laterally spaced sealing members which, together with opposed surfaces of the lid and body between which the sealing members are compressed in use, define an endless passage. A single port is provided which communicates with the endless passage so that pressurized gas can be introduced into the passage to test for leakage past and through (by diffusion) the sealing members.

A problem that arises with such an arrangement is the trapping of water in the endless passage which may occur in circumstances where the lid may need to be connected to the container body underwater. The water can be extracted subsequently by means of a vacuum pump connected to the port used for leak testing but this is slow and unreliable.

The object of the present invention is to provide an improved method of extracting water (liquid and vapour) from the endless passage of such a container.

According to the present invention there is provided a method of purging water from the sealing arrangement of a container of the type referred to above, said method comprising injecting gas (for example, air) into the endless passage by means of a nozzle inserted through said port while leaving an exit path to allow the injected gas to escape via the port after at least partial circulation within the endless passage.

The nozzle conveniently comprises a conduit having a lateral discharge opening and, in use, the nozzle may be located so that its discharge opening is directed to set up a flow of purging gas in one particular direction around the endless passage. However, tests have shown that this is not essential to achieving efficient purging of water from the passage.

To promote further understanding of the invention, an embodiment will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a diagrammatic plan view showing the general layout of the seals and port of a container.

Figure 2 is a diagrammatic cross-sectional view taken in the direction 2-2 of a typical sealing arrangement; and Figure 3 is a diagrammatic view taken in the direction 3-3 showing connection of a purging device to the endless passage formed by the sealing arrangement.

Referring firstly to Figs. 1 and 2, the sealing arrangement comprises a pair of endless seals 10, 12 of round section (when unstressed) accommodated in channels 14 with a common interspace 20. In use, when the lid 16 has been tightened onto the container body 18, the seals 10, 12 are trapped and compressed between opposing surfaces of the lid 16 and body 18 as shown in Fig. 2. It will be seen that the seals 10, 12 together with the lid 16 and body 18 surfaces define an endless passage 20.

A port 22 communicates with the passage 20 to enable leak testing to be carried.

Referring now to Fig. 3, the purging device comprises an inlet conduit 24 extending generally concentrically with respect to an outlet conduit 26 so as to form a clearance space therebetween. The outlet conduit 26, here shown as a T-fitting, is screwthreadedly connected to the port 22 and a seal is effected by means of O-ring 28. The inlet conduit 24 is connected to a supply of compressed air, eg. 80 PSI, by pipe 30. The extremity of the inlet conduit 24 is closed off and a lateral discharge opening 32 is formed adjacent the closed end.

In use, purging is effected by injecting compressed air into the passage 20 via the conduit 24 and discharge opening 32 which may be arranged to direct the air jet in the direction of extension of the passage 20 so as to create a circulatory flow. Because there is a clearance space 34 between the conduit 24 and the port 22, the circulating air can escape through the port 22 and leaves the purging device via outlet branch 36, thereby carrying away any water present in the passage 20.

If desired, the air flow into the passage may be pulsed so as to improve, if necessary, dislodgement of adhered water droplets within the passage 20.

A feature of the invention is that effective water purging is possible using only the port provided for leak testing, thereby avoiding the need for modification of existing containers to enable the invention to be put into practice.

1. A method of purging fluid from the sealing arrangement of a container of the type referred to, said method comprising injecting gas into said endless passage by means of a nozzle inserted through said port while leaving an exit path to allow the injected gas to escape via said port after at least partial circulation within said passage.

2. A method of purging fluid from a sealing arrangement as claimed in Claim 1 wherein said gas is injected through a lateral discharge opening in said nozzle and said nozzle is located so that a flow of said gas is set up in one particular direction around said endless passage.

3. A method as claimed in Claim 1 or 2 wherein said fluid is water.

4. A method of purging fluid from a sealing arrangement, substantially as hereinbefore

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

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Purging of fluid from sealing arrangements This invention relates to the purging of fluid, especially water from a sealing arrangement between the lid and body of a container. In a known container design, there is provided a lid to body sealing arrangement comprising a pair of laterally spaced sealing members which, together with opposed surfaces of the lid and body between which the sealing members are compressed in use, define an endless passage. A single port is provided which communicates with the endless passage so that pressurized gas can be introduced into the passage to test for leakage past and through (by diffusion) the sealing members. A problem that arises with such an arrangement is the trapping of water in the endless passage which may occur in circumstances where the lid may need to be connected to the container body underwater. The water can be extracted subsequently by means of a vacuum pump connected to the port used for leak testing but this is slow and unreliable. The object of the present invention is to provide an improved method of extracting water (liquid and vapour) from the endless passage of such a container. According to the present invention there is provided a method of purging water from the sealing arrangement of a container of the type referred to above, said method comprising injecting gas (for example, air) into the endless passage by means of a nozzle inserted through said port while leaving an exit path to allow the injected gas to escape via the port after at least partial circulation within the endless passage. The nozzle conveniently comprises a conduit having a lateral discharge opening and, in use, the nozzle may be located so that its discharge opening is directed to set up a flow of purging gas in one particular direction around the endless passage. However, tests have shown that this is not essential to achieving efficient purging of water from the passage. To promote further understanding of the invention, an embodiment will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a diagrammatic plan view showing the general layout of the seals and port of a container. Figure 2 is a diagrammatic cross-sectional view taken in the direction 2-2 of a typical sealing arrangement; and Figure 3 is a diagrammatic view taken in the direction 3-3 showing connection of a purging device to the endless passage formed by the sealing arrangement. Referring firstly to Figs. 1 and 2, the sealing arrangement comprises a pair of endless seals 10, 12 of round section (when unstressed) accommodated in channels 14 with a common interspace 20. In use, when the lid 16 has been tightened onto the container body 18, the seals 10, 12 are trapped and compressed between opposing surfaces of the lid 16 and body 18 as shown in Fig. 2. It will be seen that the seals 10, 12 together with the lid 16 and body 18 surfaces define an endless passage 20. A port 22 communicates with the passage 20 to enable leak testing to be carried. Referring now to Fig. 3, the purging device comprises an inlet conduit 24 extending generally concentrically with respect to an outlet conduit 26 so as to form a clearance space therebetween. The outlet conduit 26, here shown as a T-fitting, is screwthreadedly connected to the port 22 and a seal is effected by means of O-ring 28. The inlet conduit 24 is connected to a supply of compressed air, eg. 80 PSI, by pipe 30. The extremity of the inlet conduit 24 is closed off and a lateral discharge opening 32 is formed adjacent the closed end. In use, purging is effected by injecting compressed air into the passage 20 via the conduit 24 and discharge opening 32 which may be arranged to direct the air jet in the direction of extension of the passage 20 so as to create a circulatory flow. Because there is a clearance space 34 between the conduit 24 and the port 22, the circulating air can escape through the port 22 and leaves the purging device via outlet branch 36, thereby carrying away any water present in the passage 20. If desired, the air flow into the passage may be pulsed so as to improve, if necessary, dislodgement of adhered water droplets within the passage 20. A feature of the invention is that effective water purging is possible using only the port provided for leak testing, thereby avoiding the need for modification of existing containers to enable the invention to be put into practice. CLAIMS

1. A method of purging fluid from the sealing arrangement of a container of the type referred to, said method comprising injecting gas into said endless passage by means of a nozzle inserted through said port while leaving an exit path to allow the injected gas to escape via said port after at least partial circulation within said passage.

2. A method of purging fluid from a sealing arrangement as claimed in Claim 1 wherein said gas is injected through a lateral discharge opening in said nozzle and said nozzle is located so that a flow of said gas is set up in one particular direction around said endless passage.

3. A method as claimed in Claim 1 or 2 wherein said fluid is water.

4. A method of purging fluid from a sealing arrangement, substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.

5. A nozzle for use with the sealing arrangement of a container of the type referred to comprises an outlet conduit provided with means for connecting said nozzle to said port and an inlet conduit extending through said outlet conduit so that the discharge opening of said inlet conduit locates in said endless passage, and there is provided a space between said outlet conduit and said inlet conduit so that fluid injected into said endless passage by way of said inlet conduit can exit from said endless passage through said space.

provided between said inlet conduit and said outlet conduit.

6. A nozzle as claimed in Claim 5 wherein said means for connecting said nozzle to said port comprises a screwthread.

7. A nozzle as claimed in Claim 6 or 5 wherein said discharge opening is a lateral discharge opening.

8. A nozzle substantially as hereinbefore described with reference to, and as shown in Fig. 3.