Patent Description:
Conventionally, as illustrated in, for example, <FIG>, such a watertight testing device includes a cylindrical body <NUM> fit into a pipe joint part <NUM>, an annular first water-stop bag <NUM> that is expandable and shrinkable to provide sealing between the outer surface of one end of the cylindrical body <NUM> and the inner surface of one pipe <NUM>, an annular second water-stop bag <NUM> that is expandable and shrinkable to provide sealing between the outer surface of the other end of the cylindrical body <NUM> and the inner surface of the other pipe <NUM>, an injection pipe <NUM> for injecting compressed air into the first and second water-stop bags <NUM> and <NUM> so as to expand the first and second water-stop bags <NUM> and <NUM>, and a water filling pipe <NUM>.

The water filling pipe <NUM> is a pipe for filling a test space <NUM> with water from the inside of the cylindrical body <NUM>. The test space <NUM> is formed between the outer surface of the cylindrical body <NUM> and the inner surfaces of the pipes <NUM> and <NUM> in a pipe diameter direction B and between the first water-stop bag <NUM> and the second water-stop bag <NUM> in a pipe axial direction A.

With this configuration, as illustrated in <FIG>, the cylindrical body <NUM> is set in the pipe joint part <NUM> with the shrunk first and second water-stop bags <NUM> and <NUM>. Compressed air is then injected into the first and second water-stop bags <NUM> and <NUM> from the injection pipe <NUM>. Thus, as illustrated in <FIG>, the first and second water-stop bags <NUM> and <NUM> are expanded in the pipe diameter direction and are pressed to the inner surfaces of the pipes <NUM> and <NUM>, so that the first water-stop bag <NUM> provides sealing between the outer surface of one end of the cylindrical body <NUM> and the inner surface of one pipe <NUM>, and the second water-stop bag <NUM> provides sealing between the outer surface of the other end of the cylindrical body <NUM> and the inner surface of the other pipe <NUM>.

Thereafter, the test space <NUM> is filled with water from the water filling pipe <NUM>, and then a watertight test is conducted on the pipe joint part <NUM> by checking the presence or absence of water leakage from an elastic seal member <NUM> of the pipe joint part <NUM>.

After the completion of the watertight test, water in the test space <NUM> is drained, compressed air in the first and second water-stop bags <NUM>, <NUM> is exhausted from the injection pipe <NUM>, the first and second water-stop bags <NUM>, <NUM> are shrunk as illustrated in <FIG>, and the cylindrical body <NUM> is removed from the pipe joint part <NUM>.

See <CIT> for a description of such a watertight testing device.

<CIT> discloses a watertight testing device according to the preamble of claim <NUM>. A first pressing member presses an annular first seal member into a sealing position; the same is true for a second pressing member and an annular second seal member. Here, the front side of the respective pressing member pushes against the backside of the respective seal member.

A similar watertight testing device is disclosed in <CIT>.

<CIT> and <CIT> both disclose watertight testing devices, in which the annular first and the annular second seal member are each pressed by two respective pressing members being moved to each other. The respective seal member is released by moving the respective pressing members away from each other.

In the conventional form, however, if the first and second water-stop bags <NUM> and <NUM> are thin and one of the first and second water-stop bags <NUM> and <NUM> is broken when being handled, one of the first and second water-stop bag <NUM> and <NUM> may be easily holed. The holed first or second water-stop bag <NUM> or <NUM> is not sufficiently expanded, disadvantageously reducing sealing performance between the outer surface of the cylindrical body <NUM> and the inner surfaces of the pipes <NUM> and <NUM>.

If the first and second water-stop bags <NUM> and <NUM> are increased in thickness to be hardly holed, the first and second water-stop bags <NUM> and <NUM> are less likely to be deformed and expanded. Unfortunately, this may reduce sealing performance between the outer surface of the cylindrical body <NUM> and the inner surfaces of the pipes <NUM> and <NUM> when a watertight test is conducted.

A disadvantage of the watertight testing device of above-mentioned <CIT> is its indeterminacy regarding the guidance of the first and annular seal member by the respective pressing member during pressing and especially retracting of said pressing member.

An object of the present invention is to provide a watertight testing device that can improve sealing performance between the outer surface of a core and the inner surface of a pipe when a watertight test is conducted.

The above-mentioned technical problem is solved by a watertight testing device comprising the features of claim <NUM>.

According to the watertight testing device of the present invention, it is preferable that the first seal-member insertion space is reduced in the pipe diameter direction along a pressing direction of the first seal member,.

According to the watertight testing device of the present invention, it is preferable that the moving device moves the first pressing member and the second pressing member in a pressing direction that moves the pressing members toward each other in the pipe axial direction and a release direction that moves the pressing members away from each other in the pipe axial direction.

According to the watertight testing device of the present invention, it is preferable that the moving device includes a movable rod that is attached to one of the first pressing member and the second pressing member and is movable in the pipe axial direction, a receiving member provided on the movable rod, and an extendable drive that is extendable in the pipe axial direction,.

According to the watertight testing device of the present invention, it is preferable that when the first and second pressing members each move in the release direction and return to a release position, the first and second seal members are released, and
the core is provided with a moving-range regulating member that limits an excessive movement of the first and second pressing members beyond the release position in the release direction.

The watertight testing device of the present invention further includes a plurality of wheels for movement in one of the pipes and the other pipe,
wherein the wheels are omni wheels rotatable in the pipe axial direction and a pipe circumferential direction.

As has been discussed, according to the present invention, the core is set in the pipe joint part, and the moving device moves the first and second pressing members in the pipe axial direction, so that the first pressing member presses and compresses the first seal member into the first seal-member insertion space, and the second pressing member presses and compresses the second seal member into the second seal-member insertion space. Thus, the compressed first seal member provides sufficient sealing between the outer surface of the core and the inner surface of the one pipe, and the compressed second seal member provides sufficient sealing between the outer surface of the core and the inner surface of the other pipe, thereby improving seal performance between the outer surface of the core and the inner surface of the pipe.

Thereafter, the water is fed into the test space by the test fluid feeder, and a watertight test is conducted on the pipe joint part by checking, for example, the presence or absence of leakage of water from the seal member of the pipe joint part.

In a first embodiment, as illustrated in <FIG>, reference numeral <NUM> denotes a pipe joint where a socket <NUM> of one pipe <NUM> receives an inserted spigot <NUM> of the other pipe <NUM>. The pipes <NUM> and <NUM> are, for example, PN pipes made of ductile. The pipes <NUM> and <NUM> are disposed to be joined to each other in a pipeline construction shaft <NUM> formed in the ground and constitute a pipeline <NUM>.

As illustrated in <FIG>, the inner surface of the socket <NUM> has a lock-ring storage groove <NUM> and a seal-member attachment recess <NUM>. The lock-ring storage groove <NUM> is located between the seal-member attachment recess <NUM> and an opening end <NUM> of the socket <NUM> in a pipe axial direction A.

The lock-ring storage groove <NUM> accommodates a lock ring <NUM> for preventing removal. In the seal-member attachment recess <NUM>, an annular seal member <NUM> made of an elastic material such as rubber is attached. The seal member <NUM> is interposed between the inner surface of the socket <NUM> and the outer surface of the spigot <NUM> and is compressed in a pipe diameter direction B. This provides sealing between the socket <NUM> and the spigot <NUM>.

Reference numeral <NUM> denotes a watertight testing device of the pipe joint <NUM>. The watertight testing device <NUM> is configured as follows:.

The watertight testing device <NUM> includes a core <NUM>, first and second seal members <NUM> and <NUM>, first and second pressing members <NUM> and <NUM>, a moving device <NUM>, a test fluid feeder <NUM>, and a support member <NUM>.

As illustrated in <FIG>, the core <NUM> includes a cylindrical body <NUM> fit into the pipe joint <NUM>, a pair of support plates <NUM> and <NUM> provided on both ends of the body <NUM>, and a short pipe <NUM> provided between the support plates <NUM> and <NUM>.

The body <NUM> has an extended part <NUM>, which extends outward in the pipe diameter direction B, at the center in the pipe axial direction A. The outer diameter of the extended part <NUM> is set larger than the outer diameters of both ends <NUM> and <NUM> of the body <NUM> in the pipe axial direction A. As illustrated in <FIG> and <FIG>, a pair of tapered surfaces <NUM> and <NUM> that gradually increase in diameter from the ends <NUM> and <NUM> to the extended part <NUM> are circumferentially formed at the boundaries between the outer surfaces of the ends <NUM> and <NUM> of the body <NUM> and the outer surface of the extended part <NUM>.

The support plates <NUM> and <NUM> are opposed to each other in the pipe axial direction A. The short pipe <NUM> is disposed at the center in the body <NUM> such that the body <NUM> and the short pipe <NUM> are coaxially arranged.

The first seal member <NUM> is an annular member made of an elastic material such as rubber and provides sealing between the outer surface of the core <NUM> and the inner surface of the one pipe <NUM>. The second seal member <NUM> is an annular member made of an elastic material such as rubber and provides sealing between the outer surface of the core <NUM> and the inner surface of the other pipe <NUM>.

The first and second seal members <NUM> and <NUM> each have a valve part <NUM> circular in cross section and a proximal-end part <NUM> rectangular in cross section. The hardness of the proximal-end part <NUM> is set higher than that of the valve part <NUM>. The first and second seal members <NUM> and <NUM> each have an engagement recess <NUM> circumferentially formed on the outer surface of the proximal-end part <NUM>.

Between the outer surface of the core <NUM> and the inner surface of the one pipe <NUM>, a first seal-member insertion space <NUM> is circumferentially formed. Between the outer surface of the core <NUM> and the inner surface of the other pipe <NUM>, a second seal-member insertion space <NUM> is circumferentially formed.

As illustrated in <FIG>, <FIG>, and <FIG>, the first pressing member <NUM> presses and compresses the first seal member <NUM> into the first seal-member insertion space <NUM>. The first pressing member <NUM> includes a cylindrical pressing part <NUM>, a disk part <NUM> provided on the pressing part <NUM>, a circular short cylinder <NUM> provided at the center of the disk part <NUM>, and an engagement protrusion <NUM> circumferentially formed on the inner surface of the pressing part <NUM>.

As illustrated in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, the second pressing member <NUM> presses and compresses the second seal member <NUM> into the second seal-member insertion space <NUM>. The second pressing member <NUM> includes a pressing part <NUM>, a disk part <NUM>, a short cylinder <NUM>, and an engagement protrusion <NUM> like the first pressing member <NUM>. The disk part <NUM> has circular holes <NUM>.

In a part where the tapered surface <NUM> is formed, the first seal-member insertion space <NUM> is reduced in the pipe diameter direction B along a pressing direction C of the first seal member <NUM>. Moreover, in a part where the tapered surface <NUM> is formed, the second seal-member insertion space <NUM> is reduced in the pipe diameter direction B along a pressing direction C of the second seal member <NUM>. Thus, as illustrated in <FIG> and <FIG>, the first seal member <NUM> is compressed in the pipe diameter direction B while being pressed into the first seal-member insertion space <NUM>, whereas the second seal member <NUM> is compressed in the pipe diameter direction B while being pressed into the second seal-member insertion space <NUM>.

As illustrated in <FIG> and <FIG>, the engagement protrusion <NUM> of the first pressing member <NUM> is fit into the engagement recess <NUM> of the first seal member <NUM>, allowing the first seal member <NUM> and the first pressing member <NUM> to engage with each other in the pipe axial direction A. Furthermore, the engagement protrusion <NUM> of the second pressing member <NUM> is fit into the engagement recess <NUM> of the second seal member <NUM>, allowing the second seal member <NUM> and the second pressing member <NUM> to engage with each other in the pipe axial direction A.

The moving device <NUM> moves the first pressing member <NUM> and the second pressing member <NUM> in the pressing direction C (<FIG>) that moves the pressing members toward each other in the pipe axial direction A and a release direction D (<FIG>) that moves the pressing members away from each other in the pipe axial direction A.

As illustrated in <FIG>, <FIG>, and <FIG>, the moving device <NUM> includes a movable rod <NUM> that is attached to the second pressing member <NUM> and is movable in the pipe axial direction A, a receiving member <NUM> provided on the distal end of the movable rod <NUM>, and a plurality of double-acting jacks <NUM> (an example of an extendable drive) that are extendable in the pipe axial direction A.

The movable rod <NUM> is a cylindrical member that is inserted from the second pressing member <NUM> into the short pipe <NUM>, penetrates the core <NUM>, is inserted into the short cylinder <NUM>, is inserted into the first pressing member <NUM>, and penetrates the backside of the first pressing member <NUM> on the opposite side from the second pressing member <NUM>. The receiving member <NUM> is opposed to the backside of the first pressing member <NUM> in the pipe axial direction A. The double-acting jacks <NUM> are attached between the first pressing member <NUM> and the receiving member <NUM>.

The double-acting jack <NUM> includes a jack body <NUM> and an extendable plunger <NUM>. The jack body <NUM> is attached to the receiving member <NUM> while the tip of the plunger <NUM> is attached to the first pressing member <NUM>.

As illustrated in <FIG>, <FIG>, <FIG>, and <FIG>, the support member <NUM> is a member for supporting the core <NUM>, the first and second pressing members <NUM> and <NUM>, and the moving device <NUM>. The support member <NUM> includes a shaft body <NUM> inserted into the movable rod <NUM>, a plurality of leg frames <NUM> provided on both ends of the shaft body <NUM>, and wheels <NUM> provided on the lower ends of the leg frames <NUM>.

Two of the leg frames <NUM> are provided at <NUM>° from each other on each end of the shaft body <NUM> in a pipe circumferential direction E. As illustrated in <FIG>, the wheels <NUM> are omni wheels, each including a wheel body 65a and a plurality of small auxiliary wheels 65b provided around the wheel body 65a. The wheels <NUM> are movable in the rotation direction of the wheel body 65a and a direction orthogonal to the rotation direction.

As illustrated in <FIG> and <FIG>, an operation bar <NUM> for moving the watertight testing device <NUM> from a remote location is detachably connected to the rear and of the support member <NUM>.

As illustrated in <FIG> and <FIG>, when the first and second pressing members <NUM> and <NUM> each move in the pressing direction C and reach a pressing position P1, the disk parts <NUM> of the first and second pressing members <NUM> and <NUM> are each brought into contact with one end of the body <NUM> of the core <NUM> and stop the first and second pressing members <NUM> and <NUM>.

As illustrated in <FIG> and <FIG>, when the first and second pressing members <NUM> and <NUM> each move in the release direction D and return to a release position P2, the first and second seal members <NUM> and <NUM> are released. The support plates <NUM> and <NUM> of the core <NUM> are each provided with a plurality of moving-range regulating members <NUM> that limit an excessive movement of each of the first and second pressing members <NUM> and <NUM> beyond the release position P2 in the release direction D. The moving-range regulating members <NUM> are, for example, bolts with heads 69a. The moving-range regulating members <NUM> are inserted into through holes <NUM> formed on the disk parts <NUM> of the first and second pressing members <NUM> and <NUM>.

When the watertight testing device <NUM> is set in the pipe joint <NUM>, a test space <NUM> is circumferentially formed between the outer surface of the core <NUM> and the inner surfaces of the pipes <NUM> and <NUM> in the pipe diameter direction B and between the first seal member <NUM> and the second seal member <NUM> in the pipe axial direction A. The test space <NUM> communicates with the seal-member attachment recess <NUM> via a gap <NUM> between the rear end of the socket <NUM> and the distal end of the spigot <NUM>.

As illustrated in <FIG> and <FIG>, the test fluid feeder <NUM> is a device for feeding water <NUM> (an example of a test fluid) into the test space <NUM> from the inside of the core <NUM>. The test fluid feeder <NUM> includes a feeding hose <NUM> connected to the lower part of the inner periphery of the body <NUM>, and a hydraulic pump <NUM> provided on the distal end of the feeding hose <NUM>.

Connected to the upper part of the inner periphery of the body <NUM> of the core <NUM> is an air bleeding hose <NUM> for bleeding air in the test space <NUM>. As illustrated in <FIG>, the feeding hose <NUM> and the air bleeding hose <NUM> pass through the holes <NUM> on the disk parts <NUM> of the second pressing member <NUM>.

A watertight test method for conducting a watertight test on the pipe joint <NUM> by using the watertight testing device <NUM> will be described below.

As illustrated in <FIG> and <FIG>, the spigot <NUM> is inserted into the socket <NUM> so as to join the one pipe <NUM> to the other pipe <NUM>. After that, the plungers <NUM> of the double-acting jacks <NUM> of the watertight testing device <NUM> are retracted to return the first and second pressing members <NUM> and <NUM> to the release position P2. In this state, the operation bar <NUM> is pushed and pulled to move the watertight testing device <NUM> in the pipe axial direction A to the inside of the pipe joint <NUM>.

Thereafter, as illustrated in <FIG>, the plungers <NUM> of the double-acting jacks <NUM> are extended to move the first pressing member <NUM> in the pressing direction C to the pressing position P1 and move the movable rod <NUM> of the moving device <NUM> in an opposite direction G to the first pressing member <NUM>. Thus, the second pressing member <NUM> moves in the pressing direction C to the pressing position P1.

Thus, as illustrated in <FIG>, the first pressing member <NUM> presses and compresses the first seal member <NUM> into the first seal-member insertion space <NUM>, and the second pressing member <NUM> presses and compresses the second seal member <NUM> into the second seal-member insertion space <NUM>. This allows the compressed first seal member <NUM> to provide sufficient sealing between the outer surface of the core <NUM> and the inner surface of the one pipe <NUM> and the compressed second seal member <NUM> to provide sufficient sealing between the outer surface of the core <NUM> and the inner surface of the other pipe <NUM>. Thus, seal performance improves between the outer surface of the core <NUM> and the inner surfaces of the pipes <NUM> and <NUM>.

At this point, the first and second seal-member insertion spaces <NUM> and <NUM> are reduced in the formation parts of the tapered surfaces <NUM> and <NUM> in the pipe diameter direction B. Thus, the first seal member <NUM> is compressed in the pipe diameter direction B while being pressed into the first seal-member insertion space <NUM>, whereas the second seal member <NUM> is compressed in the pipe diameter direction B while being pressed into the second seal-member insertion space <NUM>. This can easily and securely compress the first and second seal members <NUM> and <NUM>.

Thereafter, the hydraulic pump <NUM> is driven to feed the water <NUM> into the test space <NUM> from the feeding hose <NUM>. This fills the seal-member attachment recess <NUM> with the water <NUM>, which is fed into the test space <NUM>, through the gap <NUM> while bleeding air in the test space <NUM> and the seal-member attachment recess <NUM> through the air bleeding hose <NUM>. In a state where the test space <NUM> and the seal-member attachment recess <NUM> are filled with the water <NUM> at a predetermined pressure, a watertight test is conducted on the pipe joint <NUM> by checking, for example, the presence or absence of leakage of the water <NUM> from the seal member <NUM>.

After the completion of the watertight test, the water <NUM> in the test space <NUM> and the seal-member attachment recess <NUM> is drained. Thereafter, as illustrated in <FIG> and <FIG>, the plungers <NUM> of the double-acting jacks <NUM> are retracted to move and return the first pressing member <NUM> in the release direction D to the release position P2 and move the movable rod <NUM> of the moving device <NUM> in an opposite direction H to the first pressing member <NUM>. Thus, the second pressing member <NUM> moves in the release direction D to the release position P2.

At this point, the first seal member <NUM> is engaged with the first pressing member <NUM> via the engagement recess <NUM> and the engagement protrusion <NUM> and thus securely moves integrally with the first pressing member <NUM> in the release direction D. This releases the first seal member <NUM>.

The second seal member <NUM> is engaged with the second pressing member <NUM> via the engagement recess <NUM> and the engagement protrusion <NUM> and thus securely moves integrally with the second pressing member <NUM> in the release direction D. This releases the second seal member <NUM>.

When the first pressing member <NUM> returns to the release position P2, the disk part <NUM> of the first pressing member <NUM> comes into contact with the heads 69a of the moving-range regulating members <NUM>. When the second pressing member <NUM> returns to the release position P2, the disk part <NUM> of the second pressing member <NUM> comes into contact with the heads 69a of the moving-range regulating members <NUM>.

This can prevent the first and second pressing members <NUM> and <NUM> from excessively moving beyond the release position P2 in the release direction D. Thus, the first and second pressing members <NUM> and <NUM> can be easily and accurately returned to the release position P2.

The hardness of the proximal-end parts <NUM> of the first and second seal members <NUM> and <NUM> is set higher than that of the valve part <NUM>, and the engagement recess <NUM> is formed on the proximal-end part <NUM>. Thus, the proximal-end parts <NUM> are hardly deformed when the first and second seal members <NUM> and <NUM> move, thereby securely moving the first and second seal members <NUM> and <NUM>.

Thereafter, by pushing and pulling the operation bar <NUM>, the watertight testing device <NUM> is moved in the pipe axial direction A and is collected from the inside of the pipe joint <NUM>. At this point, as illustrated in <FIG> and <FIG>, the first and second pressing members <NUM> and <NUM> are returned to the release position P2 and release the first and second seal members <NUM> and <NUM>, thereby easily moving the watertight testing device <NUM>. Since the wheels <NUM> for movements are omni wheels, the watertight testing device <NUM> can easily move in the pipes <NUM> and <NUM> in the pipe axial direction A and the pipe circumferential direction E, so that the watertight testing device <NUM> can be easily removed from the pipe joint <NUM>.

In the watertight testing device <NUM>, the first and second pressing members <NUM> and <NUM> can be moved in the pressing direction C and the release direction D by using the double-acting jacks <NUM> shared by the first and second pressing members <NUM> and <NUM>, thereby reducing the kinds and the number of double-acting jacks <NUM>.

In the first embodiment, as illustrated in <FIG>, the engagement recess <NUM> is formed on each of the first and second seal members <NUM> and <NUM> while the engagement protrusion <NUM> is formed on each of the first and second pressing members <NUM>. The engagement protrusion <NUM> may be formed on each of the first and second seal members <NUM> and <NUM>, and the engagement recess <NUM> may be formed on each of the first and second pressing members <NUM>.

In the first embodiment, as illustrated in <FIG>, the engagement protrusion <NUM> of the first pressing member <NUM> is fit into the engagement recess <NUM> of the first seal member <NUM>. This engages the first seal member <NUM> and the first pressing member <NUM> in the pipe axial direction A and fits the engagement protrusion <NUM> of the second pressing member <NUM> into the engagement recess <NUM> of the second seal member <NUM>, so that the second seal member <NUM> and the second pressing member <NUM> are engaged with each other in the pipe axial direction A. However, the present invention is not limited to this configuration. For example, a second embodiment discussed below may be applied instead.

In the second embodiment, as illustrated in <FIG>, a pressing part <NUM> of a first pressing member <NUM> and a proximal-end part <NUM> of a first seal member <NUM> are connected to each other with a plurality of screws <NUM>, thereby engaging the first seal member <NUM> and the first pressing member <NUM> in a pipe axial direction A. Likewise, a pressing part <NUM> of a second pressing member <NUM> and a proximal-end part <NUM> of a second seal member <NUM> are connected to each other with a plurality of screws <NUM>, thereby engaging the second seal member <NUM> and the second pressing member <NUM> in the pipe axial direction A.

In the foregoing embodiments, as illustrated in <FIG>, the movable rod <NUM> is attached to the second pressing member <NUM> and penetrates the backside of the first pressing member <NUM>, and the receiving member <NUM> is opposed to the first pressing member <NUM>. The movable rod <NUM> may be attached to the first pressing member <NUM> and penetrate the back side of the second pressing member <NUM>, and the receiving member <NUM> may be opposed to the back side of the second pressing member <NUM>.

In the foregoing embodiments, the double-acting jack <NUM> is an example of an extendable drive. Multiple single-acting jacks in different orientations may be used instead. Alternatively, a hydraulic cylinder or the like may be used.

Claim 1:
A watertight testing device (<NUM>) for a pipe joint part, the watertight testing device (<NUM>) conducting a watertight test on the pipe joint part in which a socket (<NUM>) of one pipe (<NUM>) receives an inserted spigot (<NUM>) of another pipe (<NUM>),
the pipe joint part being provided with a seal member (<NUM>) between an inner surface of the socket (<NUM>) and an outer surface of the spigot (<NUM>),
the watertight testing device (<NUM>) comprising:
a cylindrical core (<NUM>) fit into the pipe joint part;
an annular first seal member (<NUM>) for sealing between an outer surface of the core (<NUM>) and an inner surface of the one pipe (<NUM>);
an annular second seal member (<NUM>) for sealing between the outer surface of the core (<NUM>) and an inner surface of the other pipe (<NUM>);
a first pressing member (<NUM>) for pressing and compressing the first seal member (<NUM>) into a first seal-member insertion space (<NUM>) formed between the outer surface of the core (<NUM>) and the inner surface of the one pipe (<NUM>);
a second pressing member (<NUM>) for pressing and compressing the second seal member (<NUM>) into a second seal-member insertion space (<NUM>) formed between the outer surface of the core (<NUM>) and the inner surface of the other pipe (<NUM>);
a moving device (<NUM>) for moving the first and second pressing members (<NUM>, <NUM>) in a pipe axial direction (A); and
a test fluid feeder (<NUM>) for feeding water (<NUM>) into a test space (<NUM>) formed between the outer surface of the core (<NUM>) and the inner surface of the one and other pipe (<NUM>, <NUM>) in a pipe diameter direction (B) and between the first seal member (<NUM>) and the second seal member (<NUM>) in the pipe axial direction (A),
characterized in that
the annular first seal member (<NUM>) is engaged with the first pressing member (<NUM>) via a first engagement recess (<NUM>) and a first engagement protrusion (<NUM>), and
the annular second seal member (<NUM>) is engaged with the second pressing member (<NUM>) via a second engagement recess (<NUM>) and a second engagement protrusion (<NUM>).