GB2147393A - Valve for grouting - Google Patents

Abstract

A valve for the injection of grout into the annular space (15) around a pipe lining a sewer main (16) or the like comprises a valve body (1) in the form of a sleeve to be fitted in the wall (4) of the pipe, and a coaxial inner portion (7) movably housed in the valve body (1). The valve body (1) has an outer wall (3) with a plurality of apertures (2) arranged off-axis, whilst the inner portion (7) has a single central aperture (11). In a first position of the inner portion (7), defined by snap-engagement of a lip (10) on the portion (7) in a groove (8) of body (1) the portion (7) projects into the pipe interior and the spacing between it and the valve body (1) allows the flow of grout between the central aperture (11) and the off-axis apertures (2). When injection is complete, the inner portion (7) of the valve can be pushed by a remotely controlled machine into a second position in which lip (10) snap-engages groove (9) to close the valve along an annular sealing line (14) of contact between mouth (12) of aperture (11) and centre part (13) of body (1). The combination of a central aperture (11) and off-axis apertures (2) allows a relatively large cross-sectional flow area to be achieved within a valve which, in its closed state, is to a large extent controlled within the thickness of the pipe wall (4). <IMAGE>

Description

SPECIFICATION Grouting valve This invention relates to a valve for mounting in the wall of a pipe or container, primarily for the injection of grout or similar material from the interior of a sewer lining pipe into an annular section space between the lining pipe and an outer sewer wall.

In my co-pending British Patent Application No. 83 00735 I disclose a method of grouting around a polyethylene sewer lining pipe used to line a damaged or leaking sewer.

When the lining pipe has been installed, the annular section space between the pipe and the original sewer wall is grouted by injecting liquid grout by remote control sequentially through a number of holes cut in the lining pipe at spaced intervals along its length.

Grout is injected through each hole from inside the lining pipe until the escape of grout from the next hole is detected, using for example a closed-circuit TV system. In this way, grout can be injected into the annular space along the whole length of the lining pipe in the knowledge that no substantial voids have been left between the lining pipe and the original sewer wall.

When the required amount of grout has been injected at each individual hole, the hole is blocked off before injecting grout through the next hole. This can be done, as described in the above mentioned co-pending application, by fitting, in each hole, a two-position valve which can be operated by remote control.

It is an object of this invention to provide an improved valve suitable for use in the above method. According to this invention, a valve for mounting in the wall of a pipe or container comprises a first portion shaped to be secured in a hole in the said wall, and a second portion shaped to be fitted within the first portion and movable axially between open and closed positions. When the second portion is in its open position, communication between the two sides of the wall is provided by a plurality of annularly arranged apertures in one portion of the valve and a substantially centrally located aperture in the other portion, a radial passageway connecting the central aperture with the annularly arranged apertures.When the second portion is moved to its closed position, by pushing it towards or further into the first portion, the radial passageway is blocked, so interrupting communication between the two sides of the wall.

This arrangement allows a valve of relatively small depth to be produced with a relatively large flow cross-section. The relatively small depth enables the construction of a valve with minimal protrusion on either side of the wall, so that in the grouting method described above the valve can be used when the annular space around the lining pipe is very restricted and also offers the minimum obstruction for remotely controlled devices passing through the pipe interior. Maintaining a relatively large flow cross-section allows liquid grout to be injected through the valve at a practicable pumping rate without the pressure drop across the valve being so great that 'dewatering' of the grout occurs.De-watering is the separation of the liquid and solid constituents of the grout which can occur at an orifice at high pressure differentials, leading to the build-up of solid material and eventual blocking of the orifice.

In the preferred embodiment the second, movable portion of the valve has two snap located positions in the first portion. In the above grouting method, each valve is fitted to its respective hole in the lining pipe prior to installation of the pipe in the sewer. At this stage the movable portion projects into the pipe interior. When sufficient grout has been injected through the valve, from, for example, a remotely manoeuverable injection nozzle, the movable portion of the valve can be pushed into its second, closed position by applying force with the nozzle.

The preferred embodiment is illustrated in the drawings, in which Figure 1 is a perspective view of the valve with the movable portion in the first, open position, and Figure 2 is a sectioned side elevation of the valve showing the two portions spaced apart for clarity.

In the Figures, the first portion of the valve referred to above is the generally cylindrical valve body 1, moulded in a resilient plastics material such as nylon. It has a series of outlet apertures 2 arranged annularly in an outer wall 3, the central part of the wall having no apertures. The valve body 1 is shaped externally to fit closely in a hole in a pipe wall 4, as shown by the dotted lines, and has a locating lip 5 which abuts the inner surface of the pipe wall. A second, less prominent lip 6 holds the valve body 1 in position in the pipe wall once it has been pushed home.

The second, movable portion 7 of the valve, also formed in flexible plastics material, fits into the interior space of the valve body 1 in either of two positions, these being defined by two internal grooves 8 and 9 in the valve body which receive a flexible rim 10 on the movable portion. A central inlet aperture 11 is provided in the movable portion, the diameter of the aperture being less than the distance between the innermost parts of opposite located pairs of the outlet apertures 2. Thus, when the portion 7 is in the open position defined by the innermost (with respect to the pipe) groove 8, a radial passageway exists between the inlet aperture 11 and the outlet apertures 2, but movement of the portion 7 to the second position defined by the groove 9 blocks the passageway due to the bevelled surface 12 engaging the central part 13 of the wall 3. To be precise the surface 12 engages a circular edge 14 surrounding a downwardly projecting portion of the wall 3.

The total cross-sectioned area of the outlet apertures 2 is preferably approximately equal to that of the inlet aperture 11, and each area is preferably approximately equal to the area of the injection pipe and nozzle so that no sharp pressure drop occurs across the valve.

The main advantageous features of the valve are visible in the drawing, viz. the relative shallowness, particularly when closed, and the relatively large size of the apertures for a valve of this depth. As shown, the annular space 15 between the lining pipe 4 and the original sewer wall 16 is greater than may be encountered. The minimal protrusion of the valve body 1 beyond the outer surface of the lining pipe allows the lining pipe 4 to be fitted with a much reduced annular space 15.

Claims (10)

1. A valve for mounting in the wall of a pipe or container, comprising a first valve portion shaped to be secured in a hole in the said wall, and a second valve portion shaped to be fitted within the first portion and movable axially between a first portion in which the valve is open and a second position in which the valve is closed.

2. A valve according to claim 1, wherein the second portion is held in the second position by snap location.

3. A valve according to claim 1 or claim 2, wherein one of the portions has a central closure part, a first annular contact surface portion surrounding the central closure part, and a plurality of apertures located outside the contact surface portion, and wherein the other portion of the valve has a central aperture surrounded by a second annular contact surface portion, the arrangement of the contact surface portions being such that they contact each other in the second position of the second portion to interrupt communication between the apertures of the said one portion and the central aperture of the other portion.

4. A valve according to any preceding claim, wherein the first valve portion comprises a sleeve of circular cross-section having at one end a flange for engaging an inner surface of the said pipe or container wall, a wall extending across the other end of the sleeve and having a plurality of apertures arranged annularly around a solid central part of the wall, and wherein the second valve portion comprises a ring defining a central aperture and slidable coaxially inside the sleeve of the first valve portion between the said first position in which an annular passageway connects the central aperture of the second valve portion with the apertures of the first valve portion and the said second position in which the ring engages the wall of the first valve portion along an annular engagement line to close the said passageway.

5. A valve according to any preceding claim, wherein at least one of the valve portions is of a flexible plastics material.

6. A grout injection and shut-off valve for mounting in a hole in the wall of a pipe, comprising a hollow outer valve member shaped to be secured in the said hole, and an inner valve member housed in the outer valve member, the inner valve member being movable axially in the outer valve member between a first position and a second position, one of the said valve members having a central aperture surrounded by a first annular contact portion, and the other of the said valve members having a plurality of off-centre apertures lying outside a second annular contact portion, the mounting of the inner valve member in the outer valve member being such that, in the said second position, the two contact portions engage each other to interrupt a flow path between the central aperture and the off-centre apertures.

7. A valve according to claim 6, wherein the inner valve member projects from the outer valve member when in its first position, and is substantially flush with or totally received within the outer valve member when in its second position.

8. A valve according to claim 6 or claim 7, wherein the outer valve member has flange means for engaging the inner surface of the pipe.

9. A valve according to any of claims 6 to 8, wherein at least one of the contact portions has a frusto conical surface.

10. A valve constructed and arranged substantially as herein described and shown in the drawing.