JPH02133253A - Piping device for tank lorry - Google Patents

Abstract

PURPOSE:To contrive the improvement of work efficiency by providing an opening and closing valve in the second connection pipe, which connects a front end outflow point of a manifold pipe to a discharge pipe, to serve as the check valve impeding a reverse flow from the discharge pipe. CONSTITUTION:When liquid in a tank chamber is unloaded, the liquid is guided to a manifold pipe 12 via bottom valves 10 in opening, forced to be press fed to a discharge pipe 14 by driving a pump 22 and unloaded from delivery valves 16 being opened. Here a reverse flow tends to occur in the second connection pipe 20 from the discharge pipe 14 to a front part outflow point B, but a check valve 26 impedes the reverse flow. While in the time of unloading the liquid by its own weight, a selector valve 21 is switched to a pump bypassing side, and the liquid, fed out to the manifold pipe 12 from the bottom valves 10, is allowed to flow in the discharge pipe 14 through the first connection pipe 18 from an intermediate part outflow point A while through the second connection pipe 20 and the check valve 26 from the front part outflow point B thus unloaded from the delivery valve 16. Thus prior to driving the pump, trouble is eliminated of closing the second connection pipe, while the reverse flow due to forgetting to close the valve can be surely avoided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a piping device for unloading a tank lorry that transports liquid such as petroleum, and more specifically, to prevent liquid from remaining in the unloading piping of a tank lorry. The present invention relates to a piping device for a tank lorry that can prevent such problems.

[Conventional technology]

FIG. 6 is a schematic circuit diagram of conventional piping for discharging oil from a tank of a tank truck. The tank of the tank lorry is divided and partitioned into four tank chambers in the front and rear direction, and a bottom valve 10 is provided at the bottom of each tank chamber and is opened and closed by manual operation. The manifold piping 12 extends in the longitudinal direction of the tank lorry at the bottom of the tank, and is connected to each tank chamber via each bottom valve 10. The intermediate outflow point A and the front end outflow point B are set at the intermediate and front end positions of the manifold piping 12, respectively, with respect to the front-rear direction of the tank lorry, and the manifold piping 12 is in a state where oil is sufficiently loaded into the tank. The manifold pipe 12 is gently inclined downward at a predetermined slope from the front and rear ends of the manifold piping 12 toward the intermediate outlet point A so that the intermediate outlet point A is the lowest point. The discharge pipe 14 extends in the left-right direction at approximately the center in the longitudinal direction of the tank and below the manifold pipe 12, and the discharge valves 16 are attached to both left and right ends of the discharge pipe 14 and are manually opened and closed. . The first connecting pipe 18 connects the middle outlet point A of the manifold pipe 12 and the discharge pipe 14, the second connecting pipe 20 connects the front end outlet point B of the manifold pipe 12 and the discharge pipe 14, The first connecting pipe 18 and the second connecting pipe 20 are sloped downward toward the discharge pipe 14 from the intermediate outlet point A and the front end outlet point B. In order to prevent oil from remaining in the discharge pipe 14 when the oil in the tank is discharged from the discharge valve 16, the discharge pipe 1
4 is inclined downward toward both discharge valves 16 from the connection point between the discharge pipe 14 and the first connecting pipe 18 and the second connecting pipe 20. The pump 22 is provided in the first connecting pipe 18 and pumps the petroleum in the manifold pipe 12 from the intermediate outlet point A to the discharge pipe 14. Manually operated bypass passage 23
selectively directs the oil from the intermediate outlet point A to the pump 22 or to a bypass passage 23 that bypasses the pump 22. The gate valve 24 is provided in the second connecting pipe 20,
The second connecting pipe 20 is opened and closed by manual operation.

As the oil in the tank decreases, the suspension spring on the rear wheel side of the tank lorry recovers, and the height difference between the intermediate outlet point A and the part of the manifold piping 12 on the front side of the intermediate outlet point A decreases. However, oil tends to remain in the manifold piping section 2 in front of the intermediate outlet point A. The second connecting pipe 20 is provided in order to avoid this, and the front end outlet point B of the front end of the manifold piping 12 is provided.
is connected to the discharge pipe 14, thereby preventing oil from remaining in the portion of the discharge pipe 14 on the front side of the intermediate outlet point A, despite the restoration of the rear wheel spring of the tank lorry.

When unloading oil from the tank chamber, it is determined whether to unload using the pump 22 or to open the gate valve 24 and unload by gravity depending on the type of oil. pump 22
In the case of unloading by using the switching valve 21,
While connecting the intermediate outlet point A side to the pump 22 side,
In order to prevent oil from flowing backward from the discharge pipe 14 side to the manifold pipe 12 side via the second connecting pipe 20, the gate valve 24 is closed.

In the case of unloading by gravity, the gate valve 24 is opened and the oil in the manifold piping 12 is discharged from the intermediate outlet point A and the front end outlet point B through the first connecting pipe 18 and the second connecting pipe 20, respectively. It is guided to piping 14.

[Problems to be Solved by the Invention] In the conventional tank lorry piping system, the gate valve 24 is opened and closed manually, so if you forget to close the gate valve 24 when discharging oil from the tank chamber by gravity, the oil may leak out. From the discharge pipe 14 via the second connecting pipe 20 to the front end outlet point B
There is a problem that the water flows backward into the tank chamber from some open bottom valves 10.

An object of the invention as claimed in claim 1 is to provide a piping device for a tank lorry that can prevent backflow due to forgetting to close the valve.

The object of the invention according to claims 2 and 3 is to prevent liquid from remaining on the upstream side of the valve body of the check valve or in the valve chamber in the check valve used in the piping device for a tank lorry according to claim 1. It is.

[Means to solve the problem]

The piping device for a tank lorry according to claim 1 includes a tank partitioned into a plurality of tank chambers in the front-rear direction, and an intermediate outlet point extending in the front-rear direction and connected to each tank chamber via a bottom valve, and intermediate in the front-rear direction. A manifold pipe with a downward slope toward the front end of the manifold pipe, and a front end outlet point set at the front end of the manifold pipe.

A discharge pipe that extends in the left-right direction below the manifold pipe and has a discharge valve at its end, a first connection pipe that connects the intermediate outlet point to the discharge pipe, and a first connection pipe that connects the intermediate outlet point to the outlet pipe. a switching valve that bypasses the pump in the first connection pipe and directs the liquid from the middle outlet point to the discharge pipe; and a second connection that connects the front end outlet point to the discharge pipe. Piping and this second
and an on-off valve provided in the connecting pipe. The on-off valve is a check valve that prevents liquid from flowing backward from the discharge pipe to the front end outlet point.

In the piping device for a tank lorry according to claim 2, the check valve has an inlet passage communicating with the front end outlet point, and an inlet passage communicating with the discharge pipe, the center line of which is parallel to the center line of the inlet passage, and the lower side. a valve seat formed obliquely with respect to a vertical plane at the downstream end of the inlet passage so that its lower end projects toward the outlet passage with respect to its upper end; The valve body is supported at the upper end so as to be able to swing freely and is spaced apart from the valve seat at the lower end in a free state.

In the piping device for a tank lorry according to claim 3, the check valve has a passage forming a part of the second connection pipe, and is rotatably disposed within the passage, and is in a vertical position in a free state and is disposed at a lower end thereof. It has a valve body that leaves a gap between it and the passage, and a stopper that can come into contact with the upper end of the valve body to prevent the lower end of the valve body from swinging toward the front end outflow point. are doing.

[Effect]

In the invention of claim 1, when the liquid in the tank chamber is discharged by the pump, the liquid led to the manifold piping through the open bottom valve is forced to be sent from the manifold piping to the discharge piping by driving the pump. The high pressure liquid in the discharge pipe is discharged through the discharge valve which is open. In addition, the high-pressure liquid in the discharge pipe flows from the discharge pipe toward the front end outlet point.
However, the check valve prevents the flow toward the front end outflow point.

If unloading is carried out by gravity, the switching valve 21 bypasses the pump and allows the liquid from the intermediate outlet to flow into the first connecting pipe. The liquid that has exited into the manifold piping via the bottom valve flows to the intermediate outlet point and the front end outlet point of the manifold piping, and further flows into the first connecting pipe and the second connecting pipe.
The liquid introduced into the first connecting pipe bypasses the pump and flows to the discharge pipe. On the other hand, the check valve allows liquid to flow from the front end outflow point of the second connecting pipe to the discharge pipe, so the liquid guided towards the second connecting pipe passes through the check valve and is discharged. It reaches the pipe and joins with the liquid from the first connecting pipe.

guided to the discharge valve.

In the invention of claim 2, when unloading by one gravity, in the check valve, the liquid guided from the front end outflow point to the inlet passage collides with the valve body, and the valve body rotates at the upper end due to this collision force. It swings around the moving point and moves away from the valve seat. This causes the liquid to flow through the valve seat into the outlet passage and into the discharge pipe.

When the flow of liquid from the front end outflow point of the second connecting pipe to the discharge pipe stops, the collision force of the liquid from the inlet passage side of the check valve to the valve body disappears, and the valve body The valve element rotates around the rotation point of the upper end and becomes free, leaving a predetermined gap between the lower end of the valve body and the valve seat.

The inlet passage is located at a higher level than the outlet passage, and the liquid remaining in the inlet passage passes through the gap between the valve seat and the valve body, falls into the outlet passage, and flows by gravity to the discharge pipe.

During unloading by the pump, the high pressure liquid in the discharge pipe flows in the second connecting pipe towards the check valve. The liquid collides with the valve body of the check valve from the outlet passage side, and the collision force presses the valve body against the valve seat. In this way, the liquid is prevented from flowing from the outlet passage side to the inlet passage side at the check valve.

In the invention of claim 3, when unloading by gravity, in the check valve, the liquid guided from the front end outflow point side to the passage portion collides with the valve body, and the valve body is rotated by this collision force, Increase opening. As a result, the liquid passes through the check valve through the gap between the open valve body and the passage, and reaches the discharge pipe.

When the flow of liquid from the front end outlet point of the second connection pipe to the discharge pipe stops, the collision force of the liquid from the front end outlet point side of the check valve to the valve body disappears, and the valve body It becomes a free state, rotates due to gravity, and assumes a vertical position.
A predetermined gap is left between the lower end of the valve body and the passage.

The liquid remaining on the front end outflow point side of the valve body flows to the discharge pipe by gravity through the gap between the valve body and the passage.

During unloading by the pump, the high pressure liquid in the discharge pipe flows in the second connecting pipe towards the check valve. The liquid collides with the valve body from the discharge piping side of the check valve.

The impact force urges the valve body so that its lower end swings toward the front end outflow point. As a result, the upper end of the valve body comes into contact with the stopper, and the valve body is held in an approximately vertical position.
The passage portion is maintained in a substantially fully open state, and the liquid is substantially prevented from flowing from the discharge pipe side to the front end outlet side at the check valve.

〔Example〕

Hereinafter, the present invention will be described with reference to embodiments shown in the drawings. Note that the parts already described in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 is a schematic circuit diagram of piping for discharging oil from a tank of a tank truck. The check valve 26 is.

It is provided in the second connecting pipe 20 instead of the gate valve 24 in FIG. 6, and prevents oil from flowing from the discharge pipe 14 to the front end outlet point B.

To explain the operation of the embodiment shown in FIG.
When discharging oil from the tank chamber, the intermediate outlet point A side of the switching valve 21 is connected to the pump 22 side, and the pump 22 is driven.

The oil guided to the manifold piping 12 via the open bottom valve 10 is driven by the pump 22 to the manifold piping 1.
2 to the discharge pipe 14. The high-pressure petroleum in the discharge pipe 14 is discharged through the discharge valve 16 which is open. In addition, the high-pressure petroleum in the discharge pipe 14 attempts to flow backward through the second connecting pipe 20 from the discharge pipe 14 toward the front end outflow point B, but the check valve 26 prevents the oil from flowing back toward the front end outflow point B. The flow to is blocked.

When unloading is performed by gravity, the switching valve 21 connects the intermediate outlet point A side to the bypass passage 23 side, and the pump 22 is stopped. The oil that has exited into the manifold piping 12 via the bottom valve 10 flows to the intermediate outlet point A and the front end outlet point B of the manifold piping 12, and then to the first connection IP! 18 and second connecting pipe 20
will be introduced to The oil guided to the first connecting pipe 18 bypasses the pump 22, flows through the bypass passage 23, and reaches the discharge pipe 14. In addition, since the check valve 26 allows oil to flow from the front end outlet point B of the second connecting pipe 20 to the discharge pipe 14, the oil flowing into the second connecting pipe 20 is
It passes through the check valve 26 and reaches the discharge pipe 14. As a result, the oil from the first connecting pipe 18 and the second connecting pipe 20 join together in the discharge pipe 14, and further, the oil from the discharge valve 16
be led to.

FIG. 2 is a sectional view of a check valve 28, which may be applied as the check valve 26 in FIG. 1, but whose structure itself is already known. In the check valve 28, a passage 30 is formed in the casing 32 so as to pass through the casing 32, and a centerline 34 of the passage 30 is aligned in a substantially horizontal direction within the casing 32. The valve chamber 36 is.

The diameter of the casing 3 is larger than that of both ends of the passage 30.
2, that is, at the center of the passage 30, the valve seat 38 is provided so as to face the valve chamber 36 from the front end outlet point B side, is not perpendicular to the center line 34, and has a lower end. It is inclined with respect to the vertical plane so as to protrude toward the discharge pipe 14 from the upper end. The valve body 40 is disposed within the valve chamber 36, and its upper end portion is rotatably supported by a support portion 42 protruding from the upper surface of the valve chamber 36 via a pin portion 44. When oil flowing from the front end outflow point B side to the wandering piping 14 side collides with the valve body 40, the valve body 40 rotates around the axis of the pin part 44 due to the collision force, and the lower end part is moved toward the valve seat. 38
away from. As a result, oil passes through the gap between the valve seat 38 and the valve body 40.

It flows to the discharge piping 14 side. Further, when the oil tries to flow from the discharge pipe 14 side to the front end outlet point B side, the oil collides with the valve body 40 from the discharge pipe 14 side, and the valve body 40 is moved to the valve seat 38.
to press. As a result, oil is prevented from flowing backward from the discharge pipe 14 to the front end outlet point B. Such a check valve 28
can be used as the check valve 26 in FIG.
6 is depressed relative to the passage 30, there is a problem that oil remains in the lower part of the valve chamber 36. Further, when the flow force of the oil from the front end outlet point B side decreases and becomes less than the rotational force of the valve body 40 due to gravity, the valve body 40 moves toward the valve seat 3.
8, the oil valve disengages due to gravity and enters a closed state, resulting in oil remaining on the front end outlet point B side of the valve body 40.

FIG. 3 is a sectional view showing an example of the check valve 26 shown in FIG. 1. Components common to those in FIG. 2 are designated by the same reference numerals, and explanations thereof will be omitted. In the check valve 26a of FIG. 3, the inlet side passage part 46 and the outlet side passage part 48 are connected to the front end outlet point B side and the discharge pipe 14 side, respectively.
The center lines 50 and 52 of the outlet side passage section 48 are parallel to each other and extend substantially horizontally, and the center line 50 is parallel to the center line 50.
It is higher than 2 by Ll. Further, the valve seat 54 is formed as an opening at the end of the inlet side passage 46 on the outlet side passage 48 side, and is not perpendicular to the center line 34 like the valve seat 38 in FIG. part is connected to the upper end of the discharge pipe 1
It is inclined with respect to the vertical plane so as to protrude toward the 4th side.

However, the amount of protrusion is smaller than that of the valve seat 38,
It is closer to the vertical direction than in the case of the valve seat 38.

As a result, in the free state where the valve body 40 is in a substantially vertical position, the lower end of the valve body 40 is separated from the lower end of the valve seat 38 by L2. The lower peripheral wall of the outlet side passage section 48 is connected to the valve seat 54.
It is parallel to the center line 52 all the way to the bottom, and has a shape with no depressions in the middle.

When the check valve 26a shown in FIG. 3 is used together with the check valve 26 shown in FIG. The oil collides with the valve body 40, and the valve body 40 swings around the axis of the pin portion 44 due to this collision force and separates from the valve seat 54. As a result, oil passes through the valve seat 54 into the outlet side passage section 4.
8 and reaches the discharge pipe 14.

When the flow of oil from the front end outflow point B of the second connecting pipe 20 toward the discharge pipe 14 stops, the collision force of the oil from the uneven side passage section 46 side of the check valve 26a to the valve body 40 disappears. However, the valve body 40 rotates around the axis of the pin portion 44 due to gravity and becomes free.

A predetermined gap is left between the lower end of the valve body 40 and the valve seat 54. The inlet side passage part 46 is located at a higher position than the outlet side passage part 48, and the oil remaining in the inlet side passage part 46 is removed from the valve seat 5.
4 and the valve body 40, it falls into the outlet side passage part 48, and flows to the discharge pipe 14 by gravity.

When unloading by the pump 22, the high-pressure petroleum in the discharge pipe 14 flows in the second connecting pipe 20 toward the check valve 26a. The oil collides with the valve body 40 from the outlet side passage portion 48 side of the check valve 26a, and the collision force presses the valve body 40 against the valve seat 54. In this way, oil is prevented from flowing from the outlet side passage section 48 side to the muddy side passage section 46 side at the check valve 26a.

FIG. 4 is a sectional view showing another example of the check valve 26 shown in FIG.
FIG. 5 is a view of the check valve 26b shown in FIG. Second
Portions common to those in the figures are indicated by the same reference numerals, and description thereof will be omitted. In the check valve 26b shown in FIG. 4 and FIG. constitute a part. The plurality of insertion holes 60 are formed in the flesh F of the casing 58 at equal angular intervals in the circumferential direction,
A bolt for assembling the casing 58 in the middle of the second connecting pipe 20 is inserted. The circular plate-shaped valve body 62 is connected to the passage portion 56.
It has a diameter slightly smaller than the diameter of , and is arranged in the first passage part 56 so as to leave a small gap L3 between it and the wall surface of the passage part 56. The pin 64 is integrally fixed to the valve body 62 at a location slightly lower than the upper end of the valve body 62, extends in a horizontal direction perpendicular to the passage portion 56, and is attached to the casing 5 at both ends.
It is rotatably supported by the thick wall portion of 8.

Thereby, the valve body 62 becomes rotatable around the axis of the pin 64, and the degree of opening in the passage portion 56 can be changed. The stopper 66 is formed at the upper part of the end of the passage section 56 on the discharge pipe 14 side so as to be directed toward the front end outlet point B side and project downward, and comes into contact with the upper end of the valve body 62. It is now possible. The valve body 62 has a stopper 6 at the upper end.
6, the lower end is prevented from swinging toward the front end outflow point B based on the vertical position of the valve body 62 in its free state.

The check valve 26b in FIGS. 4 and 5 is the same as the check valve 26b in FIG.
When unloading by gravity, oil guided from the front end outflow point B side to the passage part 56 collides with the valve body 62 in the check valve 26b, and the valve body 62 is moved by this collision force. It rotates around the axis of the pin 64 to increase the opening degree. As a result, oil.

It passes through the check valve 26b through the gap between the valve body 62 in the open state and the passage portion 56, and reaches the discharge pipe 14.

When the flow of oil from the front end outlet point B of the second connecting pipe 20 toward the discharge pipe 14 stops, the collision force of the oil from the front end outlet point B side of the check valve 26b to the valve body 62 disappears. Then, the valve body 62 becomes free and rotates around the axis of the pin 64 due to one gravitational force, and assumes a vertical position, leaving a gap of dimension L3 between the lower end of the valve body 62 and the passage portion 56. It will be done. The oil remaining on the front end outflow point B side with respect to the valve body 62 flows through the aforementioned gap between the valve body 62 and the passage portion 56 to the discharge pipe 14 side by gravity.

When unloading by the pump 22, the high-pressure oil in the discharge pipe 14 flows through the second connecting pipe 20 toward the check valve 26b. Oil flows from the discharge pipe 14 side to the valve body 6 at the check valve 26b.
2, and the impact force urges the valve body 62 so that its lower end swings toward the front end outflow point B side. As a result, the upper end of the valve body 62 comes into contact with the stopper 66, and the valve body 62 comes into contact with the stopper 66.
2 is held in an almost vertical position.

The valve body 62 is maintained in an almost fully open state leaving only a small gap L3 between the valve body 62 and the wall surface of the passage portion 56.

As a result, a negligible amount of petroleum flows from the discharge pipe 14 side to the front end outlet point B side in the check valve 26b, and the oil flow is substantially blocked.

〔Effect of the invention〕

In the invention of claim 1, the first connection pipe that connects the front end of the manifold pipe and the discharge pipe is provided with a check valve, and the check valve is manually opened and closed by an operator. This allows the liquid to flow from the front end outflow point to the discharge piping, and prevents the liquid from flowing back from the discharge piping to the front end outflow point. Therefore, the effort of closing the second connecting pipe prior to driving the pump is omitted, improving work efficiency. Further, backflow caused by forgetting to close the on-off valve in the second connection pipe can be reliably avoided.

In the invention of claim 2, when the valve body of the check valve is in a free state, the valve body rotates due to one gravity, leaving a predetermined gap between it and the valve seat, and the inlet passage is further away from the outlet passage. It's getting expensive. Therefore, the remaining liquid in the inlet passage can flow through the gap between the valve body and the valve seat to the outlet passage, and it is possible to prevent liquid from remaining on the front end outflow point side of the valve body.

In the invention of claim 3, in the free state of the valve body of the check valve, the valve body rotates due to gravity and assumes a nearly vertical position, and there is a predetermined gap between the lower end and the wall of the passage. leave. Therefore, the remaining liquid on the front end outflow point side of the valve body flows from the gap between the valve body and the wall of the passage to the discharge piping side, preventing liquid from remaining on the front end outflow point side of the valve body. can do.

[Brief explanation of the drawing]

Figures 1 to 5 relate to embodiments of the present invention, Figure 1 is a schematic circuit diagram of piping for discharging oil from the tank of a tank lorry, and Figure 2 is a diagram showing an example of the piping applied as the check valve in Figure 1. 3 is a sectional view showing an example of the check valve shown in FIG. 1, and FIG. 4 is another example of the check valve shown in FIG. 1. FIG. 5 is a cross-sectional view showing the check valve shown in FIG. 4 in the direction of the ■ arrow, and FIG. 6 is a schematic circuit diagram of conventional piping for discharging petroleum from the tank of a tank lorry. 10... Bottom valve, 12... Manifold piping, 14
...Discharge piping, 16...Discharge valve, 18...First connection pipe, 20...Second connection pipe, 21...Switching valve,
22...Pump, 26.26a. 26b...Check valve, 38...Valve seat, 40,62...
- Valve body, 46... Inlet side passage, 48... Outlet side passage, 50.52... Center line, 54... Valve seat, 56
...Passway part, 66...Stopper, A...Middle part outflow point, B...Front end part outflow point. Cause Diagram Manifold Piping Exhaust 6 Piping Discharge Valve First Connecting Pipe Second Connecting Pipe t71 Saisuke 22: Pump 26: Check Valve A: Middle Outlet Point B: Front End Outlet Point Diagram R/' 1 Figure

Claims (3)

[Claims] (1) A tank partitioned into multiple tank chambers in the front-rear direction, extending in the front-rear direction and connected to each tank chamber via a bottom valve, with a downward slope toward the outlet point in the middle of the front-rear direction. A manifold pipe having a front end outlet point set at the front end of the manifold pipe, a discharge pipe extending in the left-right direction below the manifold pipe and having a discharge valve at an end, and a discharge pipe having a discharge valve at an end thereof, a first connection pipe connected to the pipe; a pump that sends liquid from the intermediate outflow point to the discharge pipe via the first connection pipe; and a pump that bypasses the pump in the first connection pipe to It has a switching valve that guides the liquid from the intermediate outflow point to the discharge pipe, a second connection pipe that connects the front end outflow point to the discharge pipe, and an on-off valve provided in the second connection pipe. A piping device for a tank lorry, characterized in that the opening/closing valve is a check valve that prevents backflow of liquid from the discharge piping to the front end outlet point. (2) The check valve has an inlet passage communicating with the front end outflow point, and a center line communicating with the discharge pipe, which is parallel to and below the center line of the inlet passage. an outlet passage section; a valve seat formed obliquely with respect to a vertical plane at a downstream end of the inlet passage section such that a lower end projects toward the outlet passage section relative to an upper end; and a valve seat seated on the valve seat. 2. The piping device for a tank lorry according to claim 1, further comprising a valve body which is supported at an upper end so as to be able to swing freely and is spaced apart from the valve seat at a lower end in a free state. (3) The check valve has a passage forming a part of the second connection pipe, and is rotatably disposed within the passage, and is in a vertical position in a free state, and has a lower end connected to the passage. It has a valve body leaving a gap therebetween, and a stopper that can come into contact with the upper end of the valve body so as to prevent the lower end of the valve body from swinging toward the front end outflow point. The piping device for a tank lorry according to claim 1, characterized in that: