JPH046096A - Check valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is provided on the suction side of a pump device of a plurality of refueling devices connected to a single suction pipe connected to an underground tank of a refueling station. Regarding check valves.

[Prior Art] A check valve is provided on the suction side of a pump device of a refueling machine to prevent oil from dropping when the pump is not in operation.

As shown in FIG. 4, a conventional check valve 10A is provided in a suction pipe 2, and a valve body 12 is seated on a valve seat 13 from above. The valve is closed by the weight of the valve body 12 when not in operation, and when the pump device is driven during refueling, the valve is opened by the suction negative pressure of the pump.

[Problem to be solved by the invention] At a filling station where one suction pipe connected to an underground tank is connected to two refueling machines, for example, one of the refueling machines is used to refuel, and the pump device is stopped after refueling is completed. Then, a water hammer effect occurs due to the flow of oil, and the check valve 10A of the other fueling machine
Pressure is applied to the valve body 12 from below, the valve body 12 opens, and oil is sent to the pump device, albeit in small amounts. If this water hammer effect is repeated, oil will accumulate in the air separator of the pump device, and eventually the oil will overflow from the air vent.

SUMMARY OF THE INVENTION An object of the present invention is to provide a check valve that prevents the valve from opening due to pressure such as water hammer.

[Means for Solving the Problems] In the check valve according to the present invention, the lower end of the valve shaft extending downwardly of the valve body seated from above is connected to lowering means during processing that moves downward when pressurized.

The body of the above-mentioned check valve is formed into an elbow shape below the valve seat, and the lower part of the valve body is opened, and the lowering means during machining includes a disk with a diameter larger than the diameter of the valve seat, and the disk and the opening. It is preferable to configure the valve with a bellows pipe connected to the valve seat, or to configure a piston with a diameter larger than the diameter of the valve seat and a piston formed in an opening.

[Operation] In the check valve configured as described above, when refueling, the bellows tube contracts due to suction negative pressure and the disk moves upward, or the piston slides and moves upward to open the valve.

Furthermore, when a water hammer effect or the like occurs, a disk or piston with a larger diameter than the inner diameter of the valve seat of the valve body presses the valve body against upward movement and prevents the valve from opening.

[Example] The present invention will be described in detail below with reference to the drawings.

In Figure 1, a suction pipe 2 connected to an underground tank 1
are suction pipes 2a, 2b (hereinafter referred to collectively as 2
). One branch pipe 2a
is connected via a check valve 10 to the suction side of a pump device 4 driven by a motor 3 of a refueling machine A1. A flow meter 7 connected to a display meter 6 is interposed in the discharge pipe 5 of the pump device 4, and a nozzle 9 is connected to the end via a hose 8. The other suction pipe 2b is connected via a check valve 10 to a pump device 4 of a fueling machine A2 similar to the fueling machine A1.

The pump device 4 is also provided with an air separator 41, and the separated air is discharged into the atmosphere from an air vent 42.

In FIG. 2, a check valve 1 installed in a suction pipe 2
0, the lower part of the valve seat 13 is the elbow part 14.
, and an opening 15 is formed in the portion facing the valve body 12 .

The valve body 12 is seated on a valve seat 13 from above, and its valve stem 16 is slidably supported by a support portion 17 and extends downward;
It protrudes from the opening 15. A disk 18 having a diameter larger than the inner diameter of the valve seat 13 of the valve body 12 is attached to the lower end of the valve stem 16.
is fixedly installed, and its disk 18 and opening 15 are connected to the bellows pipe 1.
9, and the disk 18 and bellows tube 19 constitute a means for moving downward during processing.

Therefore, during refueling, the bellows tube 19 contracts due to the suction negative pressure of the pump device 4, the disk 18 moves upward, and the valve body 12 is separated from the valve seat 13 to open the valve.

Further, when pressure is applied due to water hammer or the like, the disk 18 of the valve body 12, which has an area larger than the inner diameter of the valve seat 13, is pressed and presses the valve body 12 against the valve seat 13, thereby preventing the valve body 12 from opening. . As a result, oil does not flow to the pump device 4 side, and oil does not overflow from the air vent 42 of the air separator 41.

FIG. 3 shows another embodiment of the invention, in which a check valve 10a
This is an example in which the lowering means during processing is composed of a piston 20 attached to the valve stem 16 of the valve body 12 and a cylinder 21 formed in the opening 15 of the body lla on which the piston 20 slides. This embodiment also has the same effects as the previous embodiment.

[Effects of the Invention] Since the check valve of the present invention is configured as explained above, it can prevent the valve from opening due to pressure such as water hammer effect, and can prevent oil from overflowing from the air vent. can.

[Brief explanation of drawings]

FIG. 1 is a front view showing a refueling machine equipped with a check valve embodying the present invention, and FIGS.
FIG. 4 is a side sectional view showing a conventional check valve. 10.10a...Check valve 12...Valve body
13... Valve seat 15... Opening 16... Valve stem
18... Disk 19... Bellows tube 20...
・Piston 21...Cylinder assembly 2 times Fig. 3

Claims (1)

[Claims] A check valve characterized in that a lower end of a valve shaft extending below a valve body seated from above is connected to downward movement means during pressurization that moves downward when pressurization is applied.