1. An insert (10) for use in connecting two lengths of pipe each of which has a plastics liner, the insert comprising:
an inner tubular member (12) of a plastics material for connection at either end to the liners of two pipe lengths;
an insulating sleeve (14) surrounding a central portion of the inner tubular member (12); and
a ring (16) of heat-resistant material overlying part of the insulating sleeve (14) to be positioned, in use, beneath a location at which the pipe lengths are butt welded;
the insulating sleeve (14) comprising an insulating material (22) which is at least partially enclosed by a sheath (24) such that the sheath can be mechanically connected to the interior of one of said pipe lengths.
2. An insert (10) according to claim 1, in which the insulation material (22) is totally enclosed by the sheath (24).
3. An insert (10) according to claim 1, in which the sheath (24) is a metal sheath.
4. An insert (10) according to claim 1, in which the length, thickness and materials of the insulating sleeve (14) are chosen such that the temperature at the inner tubular member (12) during welding is below a predefined temperature.
5. An insert (10) according to claim 1, in which the insulating sleeve (14) is adapted to partially collapse under the application of pipeline pressure in order to reduce the intrusion of the insert (10) into the pipeline bore.
6. An insert (10) according to claim 1, in which the insulating sleeve (14) has one axial end formed at an acute angle, which end is received in a corresponding annular groove in the inner tubular member (12).
7. An insert (10) according to claim 1, in which the outer surface of the inner tubular member (14) is formed with a plurality of grooves (20) to provide a drainage path for gases.
8. An insert (10) according to claim 1, in which said insulating material (22) is a foam.
9. A method of connecting a first pipe (40) containing a first liner (42) to a second pipe (44) containing a second liner (46), the method comprising the steps of:
providing an insert (10) in accordance with claim 1;
stretching the first liner (42) so as to extend from an end of the first pipe (40);
cutting the extended portion of the first liner (42) at a location calculated to cause the cut end of the first liner (42), upon release of the stretching force, to lie at a given position within the first pipe (40);
securing one end of the inner tubular member (12) of the insert (10) to the cut end of the first liner (42);
applying a bonding material to the insulating sleeve (14);
releasing the stretching force to cause the cut end of the first liner (42) to retract to said given position and the bonding material to bond to the internal surface of the first pipe (40);
stretching the second liner (46) so as to extend from an end of the second pipe (44);
cutting the extended portion of the second liner (46) at a location calculated to cause the cut end of the second liner (46), upon release of the stretching force, to lie at a given position within the second pipe (44);
securing the other end of the inner tubular member (12) of the insert (10) to the cut end of the second liner (46);
releasing the stretching force to cause the cut end of the second liner (46) to retract to said given position within the second pipe (44) while brining the ends of the first and second pipes (40, 44) into abutment; and
welding the abutting ends of the first and second pipes (40, 44) together.
10. A method according to claim 9, in which the bonding material is epoxy resin.
11. A method according to claim 10, in which the epoxy resin is applied to the sheath (24) of the insert (10).
12. A method according to claim 9, in which, before the first liner (42) is stretched and cut, the liner (42) is first stretched and released to allow estimation of the cutting position required to bond the insert in a position such that the butt weld overlies the ceramic ring (16).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Plant for amusement parks of the kind comprising a circuit which a series vehicles for the transport of the passengers joined one to another in an articulated way, which move along a rail track or the like, wherein said means for the transport of passengers can accommodate the passengers at different heights.
2. Plant for amusement parks according to claim 1, wherein the passengers are placed accommodated at a progressively increasing height, starting from the one of the passengers of the first row.
3. Plant for amusement parks according to claim 1, wherein said means accommodating the passengers at different heights are seats placed at different heights andor arranged in a different way with various slopes of the back.
4. Plant for amusement parks according to claim 3, wherein said seats are arranged in a position, becoming more and more straight starting from the first row.
5. Plant for amusement parks according to claim 1, wherein said means accommodating the passengers at different heights are supports whose aim is to give to the passengers the support which is necessary to bear the forces of inertia maintaining the same in an straight position.
6. Plant for amusement parks according to claim 3, wherein said means for the transport of passengers are equipped with stuffing which can eliminate the effects of eventual collision of the passengers against said means.