JPS6248573B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sleeve lining method in which a lining sleeve having an outer diameter larger than the inner diameter of a pipe to be lined is pushed into the pipe.

TFE with excellent corrosion resistance, heat resistance, abrasion resistance, etc.
(Polytetrafluoroethylene) is praised as a lining material. As shown in Fig. 1, the method for lining a pipe is to tie a string 3 to the tip of a lining sleeve 2 whose outer diameter is larger than the inner diameter of the pipe 1 to be lined, and to pass the string 3 through the pipe 1. A so-called sleeve lining method is used in which the string 3 is pulled by a winch 8 fixed to the wall 7a to forcibly draw the lining sleeve 2 into the pipe 1. This method has been applied to thin-walled TFE sleeves (the outer diameter of the lining sleeve is 100 mm, and the sleeve thickness is limited to about 2 to 3 mm). however,
The thin TFE lining is relatively easily permeable to gases such as fluorine, chlorine, and ammonia, and the base material of the tube could be corroded within a few months to a few years. Therefore, attempts have been made to increase the thickness of the lining, but it is difficult to draw the lining sleeve into the pipe, and the mechanical strength of the part 4 to which the string 3 in FIG. 1 is tied becomes a problem. Also, the first
In the method shown in the figure, a biased force tends to be applied to the lining sleeve 2, so it is difficult to pull it in strongly even though the force is being applied.

For this reason, the outer diameter of the lining sleeve and the inner diameter of the pipe to be lined have been made approximately equal to each other, and the pipe has been drawn in for use. This tendency became particularly noticeable in the case of thick walls. However, the lining pipe made by this method is weak against negative pressure fluid.
Accidents of lining peeling occurred, and lining peeling accidents also occurred frequently at plants where the temperature suddenly changes. For this reason, as shown in Figure 2,
A lining 6 is placed on a tube 1 with a groove 5 in the circumferential direction.
Peel-preventing lining pipes made of cast iron are now available on the market. The melting point of TFE is around 320℃, and the thermal decomposition temperature is also very close to the melting point. For this reason, it is not suitable as a casting material, and lining sleeves are made by performing powder molding and then firing. Therefore, forming as shown in FIG. 2 has been impossible because gas is generated on the tube and lining surface due to evaporation of the binder during firing. To deal with this, we developed FEP (Fully FEP), a material with good castability without losing much of TFE's excellent properties such as high corrosion resistance, heat resistance, and abrasion resistance.
fluorinated copolymerethylene and
propylene) and PFA (Perfluoroalkoxy
resin) was developed. The lining pipe in Figure 2 is
PFA (which has better heat resistance than FEP) is used, but although this structure appears to be resistant to negative pressure, when it is used, it shows that it is weak against negative pressure and many peeling accidents occur, so improvements are desired. ing. The cause of this accident was "sink" during lining casting.

In view of the progress of conventional technology as described above, FEP and PEA using the sleeve lining method, thick-walled TFE
There was a strong demand for a new lining. However, it is nearly impossible to meet this demand using the method shown in FIG.

In order to realize this request, there is a method in which a puller is provided at at least one end of the lining sleeve, the puller is used to pull the lining sleeve into the pipe to be lined, and the puller is removed after the puller is finished. be. This method has made it possible to fully realize the above-mentioned demands. However, this method requires that the pipe into which the lining sleeve is drawn be sufficiently fixed so that the force from the puller is applied evenly to the cross section of the lining sleeve. For this reason, the tube needs to be sufficiently fixed by a large-sized fixing device such as the wall 7. Additionally, a fixture may be required to secure a winch or the like that applies force to the puller. Furthermore, if the direction of the force applied to the puller is not fixed so that it is evenly applied to the cross section of the lining sleeve, the lining sleeve may deform and be pulled in, so a highly accurate pulling device is required.

The present invention has been made in view of the above-mentioned circumstances, and includes a stopper section provided at one end of the lining sleeve, and by pushing the lining sleeve using the stopper section, the lining sleeve has a strong To provide a sleeve lining method which enables pushing with force and allows a thick or hard lining sleeve to be easily pushed into a pipe without using a large fixing device such as a wall.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a principle perspective view showing a lining construction situation by a method according to an embodiment of the present invention. FIG. 4 is a sectional view of a main part showing a stopper portion provided on the lining sleeve in FIG. 3. Third
In the figure, 11 is a pipe to be lined, and a flange 12 is attached to one end. A winch, for example, a long bolt 22, is installed in each hole at a symmetrical position of this flange 12, and the bolt 2
2 is assembled to the push plate 20, and arranged so that the push rod 23 is pushed in by the push plate 20. 13 is a lining sleeve whose outer diameter is the same as the pipe 1 to be lined.
It has dimensions larger than the inner diameter of 1, and is suitable for FEP, PFA,
It is made of thick-walled TFE or the like, and has a stopper part 14 formed in advance at one end thereof. Stopper part 1
4 is the lining sleeve 1 as shown in FIG.
3, with the end portions tapered into a streamlined shape. Then, the push rod 23 is attached to the stopper part 14.
A stopper is set at the inlet of the flange 12 for positioning and passing it through the lining sleeve and into the pipe 11 to be lined. After completing the above setup, push the push rod 23 into the pipe with the long bolt 22, and then push the lining sleeve 13 into the pipe.
is gradually pushed into the tube 11 to be lined.
At this time, a strong force can be applied by the action of the stopper part 14 having the shape shown in FIG. while being pushed into the tube. Therefore,
The pushed-in lining sleeve 13 is prevented from elongating locally, and can have a uniform pressing force against the inner surface of the tube. When the stopper part 14 comes out from the other end of the pipe and the lining sleeve 13 is pushed in until the regular outer diameter part extends the required length from the pipe end, stop the pushing operation and remove the push plate 20, long bolt 22, and push rod. Remove 23. FIG. 5 shows the state in which the lining sleeve 13 has been pushed into the tube 11 which has flanges 12 at both ends. In the next step, the flange 12 is cut at a position A leaving a required length from the end face, and the stopper portion 14 and the excess lining sleeve 13 are removed. after that,
The lining sleeve 13 protruding from the end face of the flange 12 is heated and shaped to form a flared portion 15 as shown in FIG.

The stopper portion 14 is not limited to the one shown in FIG.
A hole is provided at the end of the push rod 23 to form a stopper portion 14a, and a tightening portion 23b provided at the end of the push rod 23 is inserted into this hole. And this tightening part 23b
By tightening the lining sleeve 13 with the push rod 23, deformation of the stopper portion 14 in contact with the push rod 23 can be prevented.

In the sleeve lining method by pushing according to the present invention, the lining sleeve can be pushed into the pipe 11 to be lined by applying force to a winch assembled to the pushing plate 20. This eliminates the need for large-sized fixing devices such as walls for fixing pipes and fixing objects for fixing winches, etc., which were required in the case of the sleeve lining method by drawing, and the device can be made more compact.

Furthermore, if a plurality of long bolts 22, for example four, are used as a winch, the force of each long bolt can be easily adjusted according to the pushing state of the lining sleeve so that an even force is applied to the cross section of the lining sleeve.

In addition, although a long bolt was used as the winch in the embodiment, a hydraulic cylinder, an electric winch, etc. may also be used.

Furthermore, in the sleeve lining method according to the present invention, the outer surface of the lining sleeve is sanded (sand blasted) to roughen the surface, or the inner surface of the pipe is also sanded to roughen the contact surface between the two. It is also possible to bond with epoxy resin, etc., and the effect of preventing peeling of the lining can be increased.

As described in detail above, in the sleeve lining method according to the present invention, a stopper portion is provided by molding or attachment at at least one end of the lining sleeve having an outer diameter larger than the inner diameter of the pipe to be lined, and this stopper portion is used. Since the lining sleeve is pushed into the pipe using the lining sleeve, a stronger force can be applied compared to the conventional method in which a string is tied to the end of the lining sleeve to pull it in. Furthermore, the force is applied to the lining sleeve through the stopper. Since the lining sleeve is applied evenly to the cross section of the pipe, it can be pushed into the pipe while giving uniform elastic deformation to the lining sleeve. For this reason, corrosion resistance,
Thick-walled or highly hard lining sleeves made of materials such as FEP, PFA, and TFE, which have excellent heat and abrasion resistance, can be pushed into pipes at room temperature. Since the lining sleeve is pushed into the pipe while undergoing uniform elastic deformation, the lining sleeve is not unevenly stretched after being pushed in, resulting in a uniform pressing force being maintained against the inner surface of the pipe. , the peeling prevention function against negative pressure fluid and temperature changes is enhanced. The sleeve lining method of the present invention essentially eliminates the problem of "sink marks" during casting because it is a method of pushing in while applying elastic deformation at room temperature.Furthermore, the sleeve lining method according to the present invention has a peel-preventing structure formed by a combination of dovetail grooves and protrusions in the axial direction. It can also be used in combination with lining pipes that have even higher anti-peeling properties.

Furthermore, it becomes possible to push the lining sleeve into the pipe to be lined using a winch assembled to the pusher plate, thereby reducing the size of the device used when inserting the lining sleeve. Further, by adjusting the force of the winch depending on the pushing state of the lining sleeve, it becomes possible to easily apply a uniform force to the cross section of the lining sleeve.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional sleeve lining method, Fig. 2 is a sectional view showing a peel-preventing lining pipe by a casting method, and Figs. 3 and 4 explain a method according to an embodiment of the present invention. Fig. 3 is an explanatory diagram explaining the construction status of the sleeve lining method according to the present invention, Fig. 4 is a sectional view of the main part showing the structure of the stopper part in Fig. 6 is a cross-sectional view of the lining sleeve shown in FIG. 5 with a flared portion formed therein; FIG. 7 is a stopper portion used in the present invention FIG. 7 is a sectional view of a main part showing another embodiment of the invention. 11... Pipe to be lined, 13... Lining sleeve, 14... Stopper part.

Claims (1)

[Scope of Claims] 1. In a sleeve lining method in which a lining sleeve having an outer diameter larger than the inner diameter of the pipe is inserted into a pipe to be lined, a stopper part is formed at one end of the lining sleeve, and the stopper part is formed at one end of the lining sleeve. lining the pipe while pushing the part into the pipe with a push rod, and when the lining is applied to the pipe and the stopper part comes out the required length from the end of the pipe, the pushing is finished, and after the pushing is finished, the stopper part is removed. Features a sleeve lining method. 2. The sleeve lining method according to claim 1, wherein the stopper portion is formed by molding the lining sleeve.