GB2102091A

GB2102091A - Apparatus for connecting together pipework ends

Info

Publication number: GB2102091A
Application number: GB08221577A
Authority: GB
Inventors: Maurice Lackenby; Kenneth Thomas Greenwood
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-07-25
Filing date: 1982-07-26
Publication date: 1983-01-26
Also published as: GB2102091B

Abstract

An expander bobbin is provided for connecting together pipework ends. The bobbin comprises telescopic pipes 1 and 2 provided with flanges 3 and 4 for connection in a gap in pipework. Sealing material 9 arranged between the pipes is disposed in an annular recess 7 extending from an end face 8 a flange 6. An annular follower 10 is urged into the recess against the sealing material by threaded studs 14 and nuts 15 so as to ensure sealing. The axial separation between flanges 3 and 4 is adjustable by means of threaded rods 16 retained in holes 18 in the flange 6. <IMAGE>

Description

SPECIFICATION Improvements in or relating to apparatuses for connecting together pipework ends The present invention relates to apparatuses for connecting together pipework ends.

Pipework installations suffer from the disadvantage that gaps which may arise in the pipework are generally not of standard size, so that expensive custom made "bobbins" have to be fabricated to suit their particular dimensions. This is a slow and costly operation as time must be allowed to measure the gap, select the pipe, measure and cut it, prepare it for accepting flanges, have the flanges "tacked" in place, take it to the site to check that it will fit, weld the flanges in place, grind and dress the flanges. This also has the effect that the pipework installation cannot be used during this period, resulting in loss of profits and delay in commissioning the installation.

In conventional pipework technology, any gap can usually only be made up in increments of a quarter of an inch, this being the joint thickness at both ends, and even this can vary if joints of a lesser gauge are used. Thus in order to fill a gap of even relatively small dimensions, it is necessary to have available a large number of bobbins of various sizes in order to accommodate the variations in dimensions between flanges. Further, such a standard bobbin is frequently useless for any other application, for instance in a gap of different size. In this respect, the bobbin may be refabricated so as to fill a smaller gap, but this process is itself time consuming and expensive, and can only be performed a limited number of times because of the progressive reduction in size of the bobbin.

According to the invention, there is provided an apparatus for connecting together pipework ends, comprising a first pipe, a second pipe telescopically received within the first pipe, connection means disposed at a first end of the first pipe and at an opposite end of the second pipe for connecting the apparatus to the pipework ends, sealing material disposed between the first and second pipe in an annular recess in the first pipe extending from the second end thereof, an annular follower entering the recess, and means for urging the annular follower into the recess against the sealing material.

It is thus possible to provide an apparatus or "bobbin" capable of being used to fill gaps of a range of different sizes in pipework, thus obviating the need to tailor each bobbin to an individual gap or to keep a plurality of standard sized bobbins in stock to meet various gap sizes. The bobbin may be installed very quickly and thus substantially reduces the "down-time" of an installation in which the bobbin is to be fitted. Further, the bobbin may be used as a temporary measure, after which it may be reused a virtually indefinite number of times. For instance, during a stress relieving program in pipework, the bobbin may be used to lock the pipework and may subsequently be removed for reuse elsewhere. Also, in pressure testing, sections of flange to be tested can be temporarily closed while pressure tests are completed.For instance, where no suitable bobbins are available or where valves for installation in the pipework have not yet been provided, the bobbin permits testing to proceed, thus greatly reducing delays in commissioning pipework installations.

Further, during line flushing, valves have to be removed from pipework. The bobbin may be used as a temporary replacement, or to fill gaps where temporary valves have been installed. Similarly, the bobbin may be used during pump removal or replacement in a pipework installation. Also, with instrument on-line tests, the bobbin may be used to accommodate flange length of various instruments.

Another advantage of the bobbin is its simplicity of construction. The only part likely to require attention or replacement is the sealing material and this may readily be inspected or replaced with the apparatus or bobbin installed by moving back the follower to gain access to the annular recess.

The invention will be further described, by way of example, with reference to the accompanying drawings, which is a cross-sectional view of a bobbin constituting a preferred embodiment of the present invention.

The bobbin comprises an outer pipe 1 in which is telescopically arranged an inner pipe 2. The outer pipe 1 has a flange 3 welded to a first end thereof for connection to pipework at one end of a gap to be closed, whereas the inner pipe 2 has a flange 4 disposed at the opposite end of the apparatus for connection to the other end of the gap. Both flanges 3 and 4 are provided with holes 5 for fixing to flanges at either side of the gap. The flanges 3 and 4 are welded to the respective pipes.

The other end of the outer pipe 1 is welded to a further flange 6 in which is formed an annular recess 7 extending from an end face 8 of the flange. The recess 7 contains sealing or packing material 9 for sealing the joint between the first and second pipes. A generally annular follower 10 is slidable on the inner pipe 2 and has a cylindrical portion 1 1 which enters the recess 7 for the purpose of compressing the sealing material 7.

The follower 10 also has a flange-like portion 12 in which are formed a plurality of holes 13. A plurality of studs 14 are screwed into threaded bores in the flange 6 and extend parallel to the axis of the bobbin. The other ends of the studs 14 are screw-threaded and pass freely through the holes 13 to receive respective nuts 15 on the side of the follower 10 distant from the flange 6.

Several rods 16 have first ends screwed into threaded bores 17 in the flange 4 and extend parallel to the axis of the bobbin. The rods 1 6 pass freely through holes 18 in the flange 6 and have threaded portions 19 extending throughout the majority of their length. The ends of the rods distant from the flange 4 are provided with abutment washers 20 held in place by split pins or cotter pins 21 passing through holes at the end of the rods. Nuts 22, 23, and 24 are screwed on to the threaded portion 19 of each rod with the nuts 23 and 24 being disposed on opposite sides of the flange 6.

In order to fix the bobbin in place in a gap between pipework ends, the nuts 22, 23 and 24 are released from the flange 6 on each of the rods so as to allow telescoping of the pipes 1 and 2 for the bobbin to achieve the desired length. If necessary, the follower 10 may also be released by unscrewing the nuts 1 5 to permit freer movement. The flanges 3 and 4 are bolted into place at the opposite ends of the gap after which the follower 10 is urged into the recess 7 but the nuts 15 and the nuts 22, 23 and 24 on the rods 16 are screwed to the flange 6 so as to lock the bobbin in place. The washer 20 serves to restrict telescopic opening of the outer and inner pipes 1 and 2, the maximally opened position of the pipe 2 being shown in broken lines in the drawing.

If it is desired to inspect or replace the sealing material 9, then it is merely necessary to remove the nuts 15 and pull back the follower 10 to gain access to the material 9. Thus, the sealing material may be inspected or replaced with the bobbin installed in pipework.

Claims

1. An apparatus for connecting together pipework ends, comprising a first pipe, a second pipe telescopically received within the first pipe, connection means disposed at a first end of the first pipe and at an opposite end of the second pipe for connecting the apparatus to the pipework ends, sealing material disposed between the first and second pipes in an annular recess in the first pipe extending from the second end thereof, an annular follower entering the recess, and means for urging the annular follower into the recess against the sealing material.

2. An apparatus as claimed in claim 1, in which the urging means comprise a plurality of studs fixed to the second end of the first pipe and extending slidably through holes in a flange of the follower parallel to the axis thereof, and a plurality of nuts screwed onto screw-threading on the studs and disposed on the opposite side of the follower flange from the first pipe.

3. An apparatus as claimed in claim 2, in which the studs are screwed into threaded bores in the second end of the first pipe.

4. An apparatus as claimed in any one of the preceding claims, in which the connection means comprise first and second flanges fixed to or integral with the first end of the first pipe and the opposite end of the second pipe respectively.

5. An apparatus as claimed in any one of the preceding claims, in which means are provided for limiting telescopic opening of the first and second pipes.

6. An apparatus as claimed in claim 5, in which the limiting means comprise a plurality of rods extending parallel to the axes of the first and second pipes and fixed to the opposite end of the second pipe, each rod passing slidably through a respective hole in a further flange disposed at the second end of the first pipe and having an enlargement at its end distant from the opposite end of the first pipe for abutting against the further flange to limit telescopic opening.

7. An apparatus as claimed in claim 6, in which first and second nuts disposed on opposite sides of the further flange are screwed into screwthreading on each rod to fix the relative positions of the first and second pipes.

8. An apparatus as claimed in claim 6 or 7 when dependent on claim 4, in which the rods are screwed into threaded bores in the second flange.

9. An apparatus for connecting together pipework ends, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.