JPS623713Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a manometer used for leakage inspection of gas meters, gas piping, etc.

A well-known manometer used for leakage inspection has a U-shaped glass tube (U-shaped tube) attached to a flat plate with scales, and an appropriate amount of water is poured into this U-shaped tube. Excessive pressure may cause water to overflow, or the amount of water may decrease due to evaporation, causing the water level to change, changing the positional relationship between the scale and the water surface, making it inconvenient for workers to read the scale on the water surface. In addition, the presence or absence of a leak is determined by the amount of pressure drop, as described below, but conventionally this was determined by visually following the scale of the water surface position on a manometer, which required skill and personal effort. It has the disadvantage that differences tend to appear, and it is difficult to automate testing.

In view of the above, the object of this invention is to propose an improved manometer, which is particularly suitable for use in leak testing, and is equipped with means for refilling the U-tube with water.

Next, a description will be given based on the embodiments shown in the drawings. In FIG. 1, 1 is a U-shaped tube, and when measuring pressure, measurement pressure is applied to the upper end of the left tube 1a. A water replenishing means 20 and a water surface sensor 30 are attached to the upper end of the right pipe 1b. The water refilling means 20 includes a bottom plate 23 which is fixed to the pipe 1b in a watertight manner with a gasket 21 and screws 22.
A transparent outer cylinder 24 whose lower end is held in a watertight manner by the stepped portion 23a of the bottom plate 23, an upper lid 25 which is airtightly fixed to the upper end of this outer cylinder, and one end of which is secured to the upper lid and pressurized. A connecting pipe 26 that acts as a port and a plug 2
7, a transparent inner cylinder 28 held by an upper lid 25 and a stopper 27, and a gasket 29. This water replenishing means 20 constitutes a water tank with an outer cylinder 24, an inner cylinder 28, and a bottom plate 23, and has a storage part _W1 for storing water.
and form W ₂ . The reservoirs W ₁ and W ₂ communicate with each other through a plurality of grooves 27 a cut in the stopper 27 . Note that the inner cylinder 28 extends upward from the upper end of one tube 1b of the U-shaped tube. 25a is the upper lid 25 and the inner cylinder 28
A narrow passage provided between the connecting pipe 26 and the reservoir
Connect with W ₁ . The water surface sensor 30 is connected to the inner cylinder 2
8, a movable electrode 32 that is attached to the lid 31 so as to be movable up and down, a screw 33 that fixes the movable electrode, and a screw 33 that is electrically insulated from the movable electrode 32 and fixed to the lid 31. fixed electrode 3
4, and the lower end extension portion of the fixed electrode 34 is arranged along the inner wall of the upper end of the right tube 1b of the U-shaped tube 1. Further, the lower end of the fixed electrode 32 is pointed as shown in the figure, and is disposed opposite to the center of the upper end of the tube 1b. 31a is an atmospheric communication hole.

Before using the manometer shown in Figure 1,
until reaching approximately level B-B within the water tank storage portions W _{1 and W 2 of the water replenishing means 20, and approximately level D-D within the water tank storage portions W 1} and W ₂ of the water replenishing means 20.
To add water in this way, first add water from the top of the left tube 1a of U-shaped tube 1 until the U-shaped tube is almost full.
When air pressure of approximately 300 mm of water column is applied to the upper end of pipe 1a, the water level of pipe 1a drops to level C-C, and pipe 1b
The water inside overflows from the upper end and enters the reservoir _W2 , and at the same time flows into the reservoir _W1 through the groove 27a. In this way, the U-shaped tube 1 and the water tank (reservoir) of the water refilling means 20 are filled with water in advance.

A case where the operation of the manometer shown in FIG. 1 is used for a leakage test of a gas meter shown in FIG. 2 will be described. In FIG. 2, 3 is a plate to which the U-shaped tube 1, water replenishment means 20 and water level sensor 30 are attached, 4 is a gas meter, 5 is a pipe whose one end is connected to a pressurized air source, and a two-way valve 6 is connected. The inlet 4a of the gas meter 4 communicates with the upper end of the left tube 1a of the U-shaped tube 1 through the inlet 4a of the gas meter 4. 7 is a rubber stopper with a hole in the center for connecting pressurized air to the inlet 4a of the gas meter without leakage. 8 is a rubber tube for communication, and 9 is a stopper for closing the outlet 4b of the gas meter 4. In addition, in the drawing, three gas meters and three manometer U-shaped tubes corresponding to each gas meter are connected to the piping 5, but the right end extension of the piping 5 is connected to the U-shaped tubes of other gas meters and manometers as well. Usually about 10 gas meters are inspected at the same time.

Assume that the air pressure of 300 mm of water column is present in the pipe 5 and the two-way valve 6 is closed. It is assumed that the U-shaped tube and water refilling means of each manometer are filled with water up to levels BB and DD as shown in FIG. First, apply air pressure to the connecting pipe 26 of the water refilling means 20 to lower the water level in the reservoir _W1 .
Raise the water level of W ₂ to above the upper end level of the U-shaped tube A-A, replenish the water into the tube 1b, and then remove the air pressure.

Next, a pressure of 300 mm of water column determined for gas meter leakage inspection is applied to the gas meter 4 and the left pipe 1a of the U-shaped pipe 1 using the two-way valve 6. Then, the water surface of tube 1b is at level A, which is the upper end of the tube.
-A, the excess water overflows from the upper end of the pipe 1b and flows into the reservoir _W2 . When the two-way valve 6 is closed in this state, the pressure on the left side of the U-shaped tube of the manometer will remain at 300 mm water column unless there is a leak, and the lower end of the movable electrode 32 of the water surface sensor 20 will remain in contact with the water surface. Since electrical continuity is established between the fixed electrode 34 and the fixed electrode 34 via water, the state can be determined by an external electric circuit connected to both electrodes, and the presence or absence of leakage can be notified by an appropriate lamp, buzzer, etc.
If there is a leak in the gas meter, the pressure applied to the U-shaped tube will gradually decrease from 300 mm of water column, so the water level in the tube 1b will drop and separate from the lower end of the movable electrode 32, and the external electric circuit will determine that there is a leak. Notice. In addition, since the pressure to be applied and the test time are determined for the leakage test, the presence or absence of a leak can be determined by checking whether the water surface sensor is conductive or non-conductive after a predetermined period of time has elapsed after pressurizing and closing the two-way valve. I can judge. By adjusting the position of the movable electrode 32 up and down, the amount of leakage to be detected can be continuously changed from a small value to a large value.

According to this invention, when the water level in the U-shaped pipe changes due to evaporation or the like, air pressure is applied to the connecting pipe 26,
When the water level in the reservoir _W1 in the outer cylinder 24 is lowered by air pressure, the amount of water corresponding to the lowered water level is transferred to the inner cylinder 28.
The water level in the reservoir W ₂ in the inner cylinder 28 is raised to the upper end of one pipe 1b of the U- _shaped pipe, and water can be replenished. By applying a constant air pressure to the end of the pipe 1a for leak detection, the water level is automatically adjusted, so it is convenient to use for leak detection, and a water surface sensor automatically detects a leakage amount above a certain level. becomes possible. In conventional leak testing using only U-shaped pipes, the water level was adjusted two to three times per day. In this way, the water level can always be maintained at a constant level, making it possible to turn on the lamp and issue a water alarm using an electronic circuit.
It becomes possible to save labor in inspection work. In addition, water can be replenished simply by applying air pressure, and water level adjustment time can be shortened.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of this invention, and FIG. 2 is a diagram of a gas meter leakage inspection system using the manometer of FIG. 1. 1... U-shaped tube, 1a... Left side pipe, 1b... Right side pipe (one pipe), 20... Water replenishment means, 24
... Outer cylinder, 26 ... Connection pipe as pressurizing port, 28
...Inner cylinder, 30...Water surface sensor, 32...Movable electrode, 33...Fixed electrode, _W1 ...Reservoir surrounded by outer cylinder, _W2 ...Reservoir surrounded by inner cylinder.

Claims (1)

[Scope of utility model registration request] A U-shaped tube filled with water, an inner tube arranged to surround one tube constituting the U-shaped tube and extending upward from the upper end of the one tube, and an outer tube surrounding the inner tube. a water replenishment means having a water tank, a storage part as a water tank surrounded by an inner cylinder of the water replenishment means and a storage part as a water tank surrounded by an outer cylinder are in communication at the lower part of these storage parts, and A manometer that can automatically adjust the water level, and the outer cylinder has a pressurizing port for applying pressurized air.