KR101712875B1 - Apparatus for testing airtightness of gas injection valve for gas engine - Google Patents

Abstract

The present invention relates to an apparatus to test an airtightness of a gas injection valve for a gas engine capable of testing if a gas leaks to an undesired place with the gas injection valve for a gas engine sealed with seal oil. That is, the present invention provides an apparatus to test the airtightness of the gas injection valve for the gas engine, comprising: an air-driving liquid pump which forms a supply oil pressure of sealing oil which seals the gas injection valve, and controls oil which opens a spindle guide in the gas injection valve; and a gas booster which supplies test gas to a common unit for testing airtightness formed within the gas injection valve. The apparatus of the present invention simultaneously supplies gas to the common unit for testing gas with sealing the gas injection valve with sealing oil, and is able to precisely test if gas leaks to an undesired place.

Description

TECHNICAL FIELD [0001] The present invention relates to a gas injection valve for a gas engine,

The present invention relates to a gas injection valve airtightness testing apparatus for a gas engine, and more particularly, to a gas injection valve for a gas engine, which can test whether gas is leaked to an unneeded state in a state where a gas injection valve for a gas engine is sealed, And more particularly to a gas injection valve airtightness testing apparatus for a gas engine which can test the performance of valves for gas engines.

The gas engine is a kind of internal combustion engine that converts heat energy into mechanical one by driving the piston by the combustion gas generated by the combustion of the gas fuel and by acting on the piston so that the fuel cost is lower than that of the internal combustion engine using other fuel, Because it is close to consuming, it has high efficiency and is mainly applied to marine internal combustion engine.

Wherein the gas engine includes a piston for transmitting a mechanical force generated by performing a reciprocating motion by compression and explosion of a gas fuel and air mixed mixer to the outside and a cylinder for providing a reciprocating space of the piston, A gas injection valve for introducing new gaseous fuel and air into the combustion chamber by a lift operation, and a gas injection valve for injecting new gas fuel and air into the combustion chamber by a lift operation, An exhaust valve for exhausting the combustion gas, a valve lift control device for controlling the lift of the intake valve and the exhaust valve, and the like.

The gas injection valve includes a separate gas-tight structure (e.g., a gasket, etc.) so as to inject gas only toward the combustion chamber.

Nevertheless, if the gas leaks to a location other than the combustion chamber, a gas explosion can cause a serious accident.

Therefore, a process for precisely and completely testing the presence or absence of gas tightness in a state of being separated before assembling the gas injection valve into the gas engine must be essential.

Korean Patent Laid-Open Publication No. 10-2015-0119424 (Oct. 22, 2013)

SUMMARY OF THE INVENTION It is an object of the present invention to provide an air-driven liquid pump that forms sealing oil for sealing a gas injection valve and a supply oil pressure of a control oil for opening a spindle guide in a gas injection valve, A gas booster for supplying a test gas to the gas tightness test cavity formed in the gas tight chamber is separately provided so that the gas injection valve is sealed to the sealing channel and the gas is supplied to the gas tightness test cavity, And to provide a gas injection valve airtightness testing apparatus for a gas engine which can be accurately tested.

According to an aspect of the present invention, there is provided a fuel cell system including: a sealing oil filled space which is a path through which a combustion gas flows, a control oil filled space for raising and lowering an inner spindle guide, A gas injection valve airtightness testing apparatus for a gas engine for testing the airtightness of a gas injection valve having an airtight test cavity including a gas sensing path, the apparatus comprising: a sealing oil filled in a sealing oil filled space of the gas injection valve; A hydraulic pressure forming pump for forming a supply oil pressure of control oil for opening and operating the spindle guide in the injection valve; A gas booster for directly supplying a test gas to an airtight test cavity formed in the gas injection valve; Is connected to the gas injection valve so as to form a separate independent batch line.

Particularly, the gas booster is a kind of pump operated by air pressure, in which the test gas supply container is connected to the inlet side line, the first gas shutoff valve and the gas pressure are measured in the outlet side line connected to the airtight test cavity And a second gas shutoff valve are mounted side by side.

Further, the hydraulic pressure forming pump is employed as an air driven liquid pump or an electric hydraulic pump operated by air pressure. The reservoir filled with hydraulic oil for sealing oil and control oil is connected to the inlet side line, A sealing oil pressure shutoff valve, a sealing oil pressure gauge and a sealing oil release valve are mounted side by side on the first outlet side line connected to the sealing oil filled space of the outlet side line, and a second outlet side line connected to the control oil filled space is provided with electric A solenoid valve operated by a switch, a pressure reducing valve, a control hydraulic pressure gauge, and a control fluid release valve are mounted side by side.

Preferably, the hydraulic pressure forming pump and the gas booster are connected to an air pressure supply source, and the first connection line connecting the pump for forming the hydraulic pressure and the air pressure supply source, and the second connection line connecting the gas booster and the air pressure supply source. A first air regulator, an air pressure gauge and a second air regulator are mounted side by side.

Through the above-mentioned means for solving the problems, the present invention provides the following effects.

First, it is possible to precisely test whether or not gas is leaked to an unnecessary portion by supplying gas to the gas tightness test cavity of the gas injection valve with the gas injection valve sealed in the sealing flow path.

Secondly, an air-driven pump (hydraulic pressure forming pump) for forming the supply oil pressure of the seal oil and the control oil and a gas booster for directly supplying the test gas to the airtight test cavity formed in the gas injection valve It is possible to prevent the phenomenon that the hydraulic oil (sealing oil or control oil) penetrates and is mixed into the gas booster.

Thirdly, if nitrogen is consumed during the test in the gas booster, the recharging time must be given. However, the present invention does not require unnecessary gas consumption and the performance test of the gas injection valve can be repeated.

Fourth, preliminary work to remove oxygen gas and the like in gas valve and equipment is simple and time is shortened.

In other words, in order to reduce the nitrogen consumption, the gas release valve is opened. -> The control oil release valve is closed. -> The pneumatic pressure control. It is necessary to carry out a complicated process such as increasing the gas pressure by controlling the pneumatic pressure, controlling the pneumatic pressure, opening the control oil release valve -> pneumatic '0'bar control -> gas injection -> gas shutoff -> control oil release valve, There is a very favorable advantage in operation method and test preparation time by closing the gas release valve -> removing oxygen by injecting gas -> increasing the gas booster by pneumatic control.

1 is a configuration diagram showing an embodiment of a gas injection valve airtightness testing apparatus for a gas engine according to the present invention;
2 is a cross-sectional view showing a gas injection valve which is a test object of a gas injection valve airtightness testing apparatus for a gas engine according to the present invention,
3 is a configuration diagram showing another embodiment of a gas injection valve airtightness testing apparatus for a gas engine according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention can be used not only for the airtightness test of the gas engine valve but also for the performance test of the valve for the gas engine. In addition to the gas injection valve, the present invention can also be applied to gas valves (GAS INJECTOR, WINDOW VALVE, BLOW- Such as a gas valve, a valve, a valve, a valve, a valve, a valve, a valve, a valve, a valve, a valve, a valve, a valve, a valve, and a valve.

FIG. 1 is a block diagram showing an embodiment of a gas injection valve airtightness testing apparatus for a gas engine according to the present invention, and FIG. 2 is a block diagram of a gas injection valve airtightness testing apparatus for a gas engine according to the present invention Sectional view showing a target gas injection valve, and reference numeral 10 denotes a gas injection valve.

The gas injection valve 10 is provided with a sealing oil filled space 11 which is a path through which the combustion gas originally flows for gas tightness test, a control oil filled space 12 for raising and lowering the spindle guide 14 inside, The airtightness testing cavity 13 is formed.

The sealing oil filled space 11 is a gas flow path for injecting gas into the combustion chamber of the gas engine and refers to a space filled with sealing oil for sealing the inside of the gas injection valve in the airtightness test.

The control fluid filling space 12 is a hydraulic pressure flow path for raising and lowering the spindle guide 14 mounted in the gas injection valve 10 such that the spindle guide 14 is raised and lowered. It refers to the space to be filled.

At this time, when the control oil is filled in the control fluid filling space 12, the spindle guide 14 is lifted and lowered, and the lower end nozzle portion of the gas injection valve 10 is opened.

The gas tightness test cavity 13 is a space arbitrarily formed in the gas injection valve 10 within a range that does not affect the function and performance of the gas injection valve and tests whether or not the gas leaks out to an unnecessary part Gas filling space.

At this time, the airtight test cavity 13 includes a test gas filling space 13-1 to which test gas is supplied, a test gas discharge line 13-2 to which the test gas is discharged, a gas sensing path 13- 3).

Particularly, a boundary between the gas sensing path 13-3 and the test gas filling space 13-1 and a boundary between the gas sensing path 13-3 and the test gas discharging line 13-2 are provided with a gasket Is hermetically mounted.

Therefore, it is normal that the gas sensing path 13-3 and the test gas filling space 13-1 are separated from each other by the gasket sealing part and are kept in a hermetic state. The gas sensing path 13-3 and the test gas It is required to be sealed between the discharge lines 13-2 by the gasket sealing portion so as to be hermetically sealed.

When the gasket sealing portion is abnormal, gas is supplied to the airtightness testing cavity 13 through the gas nozzle sealing portion (for example, the gasket sealing portion) other than the lower nozzle portion of the gas injection valve 10 You can test to see if it is leaked.

Here, as the hydraulic pressure forming means for filling the sealing oil filled space 11 and the control oil filled space 12 of the gas injection valve 10 with sealing oil and control oil, respectively, the hydraulic pressure forming pump 20 is connected And a gas booster 30 for directly supplying a test gas is connected to the airtightness test cavity 13 formed in the gas injection valve 10. The oil pump 20 and the gas booster 30 are connected to the gas injection valve 10 while forming separate independent batch lines.

The oil pressure forming pump 20 is an air driven liquid pump operated by air pressure. The reservoir 21 filled with hydraulic oil for sealing oil and control oil is connected to the inlet side line HL1, The first outlet side line HL2-1 connected to the sealing oil filled space 11 of the outlet side lines HL2-1 and HL2-2 is provided with a sealing oil shutoff valve 22 and a sealing hydraulic pressure gauge 23 The sealing oil release valve 24 is mounted side by side.

The second outlet side line HL2-2 connected to the control oil filled space 12 of the two outlet side lines HL2-1 and HL2-2 is provided with a solenoid valve A pressure reducing valve 27, a control hydraulic pressure gauge 28 and a control oil release valve 29 are mounted side by side.

The gas booster 30 is a kind of pump operated by the air pressure. The test gas supply vessel 31 (nitrogen tank in which nitrogen is stored) is connected to the inlet line GL1, A gas pressure gauge 33 for measuring the gas pressure and a second gas shutoff valve 34 are mounted side by side on the outlet side line GL2 connected to the outlet side line GL2.

The hydraulic pressure forming pump 20 and the gas booster 30 are connected to one air pressure supply source 40 and connected to a first connection line 40 connecting the hydraulic pressure forming pump 20 and the air pressure supply source 40. [ The first air regulator 43 and the air pressure gauge 44 and the second air regulator 45 are connected to the second connection line 42 connecting the gas booster 30 and the air pressure supply source 40, Are mounted side by side.

3, the hydraulic pressure generating pump 20 is constructed by an electric hydraulic pump instead of the air-driven liquid pump. In this embodiment, And the means for providing the air pressure can be omitted when the hydraulic pressure forming pump 20 is adopted as the electric hydraulic pump.

Hereinafter, an operational flow of the gas injection valve airtightness testing apparatus having the above-described configuration will be described.

First, the gas injection valve 10 to be tested is fixed to a predetermined jig.

Then, the first gas shut-off valve 32 mounted on the outlet line GL2 of the gas booster 30 is opened and the second gas shut-off valve 34 is closed.

At this time, a line branched from the connection line between the first gas shutoff valve 32 and the second gas shutoff valve 34 is connected to a separate gas discharge valve 35 formed in the jig, 35) is temporarily opened and operated.

Subsequently, the nitrogen tank is opened so that nitrogen flows to the outlet line GL2 of the gas booster 30, so that the air existing in the outlet line GL2 is discharged to the outside through the gas discharge valve 35 Removed.

At this time, the reason why the air existing in the outlet side line GL2 is removed is that when the gas for airtightness test is supplied to the gas injection valve 10, if the air is contained, the gas flow is obstructed and the gas tightness test is performed accurately I can not do it.

Next, an air pressure from the air pressure supply source 40 is supplied to the hydraulic pressure forming pump 20. At this time, a first connection line (not shown) for connecting the hydraulic pressure forming pump 20 and the air pressure supply source 40 The air pressure is regulated to a predetermined level by the first air regulator 43, the air pressure gauge 44, and the second air regulator 45 mounted on the first air regulator 41.

The hydraulic pressure forming pump 20 is operated to allow the hydraulic fluid from the reservoir 21 to pass through the sealing oil shutoff valve 22 (check valve) mounted on the first outlet line HL2-1, To the sealing oil filled space 11 of the gas injection valve 10 as shown in Fig.

At this time, the supply pressure of the sealing oil supplied to the sealing oil filled space 11 of the gas injection valve 10 is checked by the sealing oil pressure gauge 23, and the sealing oil of the reference value or more is supplied to the sealing oil release valve 24 And then returned to the reservoir.

Therefore, the sealing oil filling space 11 of the gas injection valve 10 is sealed by the sealing oil filled in the sealing oil filling space 11 of the gas injection valve 10.

Next, both the first gas shut-off valve 32 and the second gas shut-off valve 34 mounted on the outlet line GL2 of the gas booster 30 are opened and then the gas booster 30 is operated .

That is, the air pressure from the air pressure supply source 40 is supplied to the gas booster 30 to operate the gas booster 30. At this time, the air booster 30 and the air pressure supply source 40 The air pressure is regulated to a predetermined level by the first air regulator 43, the air pressure gauge 44 and the second air regulator 45 mounted on the second connection line 42. [

Therefore, the gas booster 30 is operated so that the test gas in the test gas supply container 31, that is, the nitrogen in the nitrogen tank, flows into the gas filling space 13- 1).

At this time, the gas discharge line (13-2) of the airtight test cavity (13) is connected to a separate gas discharge valve (35) formed in the jig, and the gas discharge valve (35) The gas is kept filled in the gas filling space 13-1 of the airtightness testing cavity 13.

A gasket (not shown), which is an essential component of the gas injection valve 10, exists between the gas filling space 13-1 of the gas tightness testing cavity 13 and the gas sensing path 13-3 , The gas filled in the gas filling space 13-1 in the steady state is sealed by the gasket and does not leak to the gas sensing path 13-3, so that the gas injection valve can be judged as good.

On the other hand, when the gasket is defective, the gas filled in the gas filling space 13-1 passes through the gasket and leaks to the gas sensing path 13-3, and flows to the outside through the gas sensing path 13-3 The leaking gas can be detected by using various sensors, bubble generating means and the like. If it is judged that the gas leaks through the gasket, the gas injection valve can be judged as defective.

On the other hand, when the gas tightness test is completed, the gas filled in the gas filling space 13-1 of the gas tightness test cavity 13 is discharged to the outside to complete the test.

When the solenoid valve 26 is opened by switching the electric switch 25 mounted on the second outlet line HL2-2 connected to the control fluid filling space 12, 20 is filled in the control oil filling space 12 as control oil. At this time, the spindle guide 14 is lifted and lowered by the control oil to be filled and the lower end nozzle portion of the gas injection valve 10 is opened.

Thus, the gas filled in the gas filling space 13-1 of the airtight test cavity 13 is discharged to the outside through the lower nozzle portion of the gas injection valve 10, thereby completing the airtightness test.

On the other hand, in order to effectively prevent and prevent the adhesion of contaminants to the surfaces of the sealing oil pressure gauge 23, the control hydraulic pressure gauge 28, the gas pressure gauge 33, and the air pressure gauge 44, An anti-fouling application layer to which the composition for application is applied is formed. The antifouling coating composition contains boric acid and sodium carbonate in a molar ratio of 1: 0.01 to 1: 2, and the total content of boric acid and sodium carbonate is 1 to 10 wt% with respect to the total aqueous solution. In addition, sodium carbonate or calcium carbonate may be used as the material for improving the coating property of the anti-fouling coating layer, but sodium carbonate is preferably used.

The molar ratio of boric acid to sodium carbonate is preferably 1: 0.01 to 1: 2. If the molar ratio is out of the above range, the coating property of the base material is lowered or the moisture adsorption on the surface is increased.

The boric acid and sodium carbonate are preferably used in an amount of 1 to 10% by weight in the aqueous solution of the composition. If less than 1% by weight, the coating property of the base material is deteriorated. If the amount is more than 10% by weight, It is easy to occur.

On the other hand, as a method of applying the present anti-contamination coating composition to surfaces of the sealing oil pressure gauge 23, the control hydraulic pressure gauge 28, the gas pressure gauge 33 and the air pressure gauge 44, . In addition, the final coating film thickness is preferably 500 to 2000 angstroms, and more preferably 1000 to 2000 angstroms. When the thickness of the coating film is less than 500 ANGSTROM, there is a problem that it deteriorates in the case of a high-temperature heat treatment. When the thickness is more than 2000 ANGSTROM, crystallization of a coated surface tends to occur.

The present anti-contamination coating composition may be prepared by adding 0.1 mol of boric acid and 0.05 mol of sodium carbonate to 1000 mL of distilled water and stirring.

In addition, the outer surface of the first air regulator 43 and the second air regulator 45 can be coated with a discoloring portion that changes color depending on the temperature. This discoloring portion is coated with two or more temperature discoloring materials whose color changes when the temperature is equal to or higher than a predetermined temperature is applied to the surfaces of the first air regulator 43 and the second air regulator 45 and separated into two or more sections Whereby a step change in temperature can be judged, and a protective film layer is applied on the discolored portion to prevent the discolored portion from being damaged.

Here, the discoloring portion may be formed by applying a temperature discoloring material having a discoloration temperature of not less than 40 DEG C and not less than 60 DEG C, respectively. The discoloring portion is for detecting changes in the temperature of the paint by changing the color according to the temperatures of the first air regulator 43 and the second air regulator 45.

The discoloring unit may be formed by applying a coloring material having a color change to a surface of the first air regulator 43 and the second air regulator 45 when the temperature of the discoloring unit is higher than a predetermined temperature. In addition, the temperature discoloring substance is generally composed of a microcapsule structure having a size of 1 to 10 탆, and the microcapsules can exhibit a colored and transparent color due to the bonding and separation phenomenon depending on the temperature of the electron donor and the electron acceptor.

In addition, the temperature-changing materials can change color quickly and have various coloring temperatures such as 40 ° C, 60 ° C, 70 ° C, and 80 ° C, and such coloring temperature can be easily adjusted by various methods. Such a temperature-coloring material may be various kinds of temperature-coloring materials based on principles such as molecular rearrangement of an organic compound and spatial rearrangement of an atomic group.

For this purpose, it is preferable that the discoloring unit is formed so as to be divided into two or more sections according to the temperature change by applying two or more temperature-coloring materials having different discoloration temperatures. The temperature-coloring layer preferably uses a temperature-coloring material having a relatively low temperature of the discoloration temperature and a temperature-discoloring material having a relatively high discoloration temperature, more preferably a discoloration temperature of not lower than 40 ° C and not lower than 60 ° C A color change portion can be formed by using a temperature coloring material.

Accordingly, the temperature change of the first air regulator 43 and the second air regulator 45 can be checked step by step, so that the change of the temperature of the paint can be detected. Accordingly, the first air regulator 43 and the second air regulator The regulator 45 can be operated in an optimal state and damage to the first air regulator 43 and the second air regulator 45 due to overheating can be prevented in advance.

In addition, the protective film layer is coated on the discolored portion, thereby preventing the discolored portion from being damaged due to external impact, easily recognizing discoloration of the discolored portion, and considering the weakness of the temperature discolored material, Is preferably used.

The first connection line 41 and the second connection line 42 may be made of metal. The first connection line 41 and the second connection line 42 of the metal material may be formed of a metal, An anti-corrosion coating layer made of a coating composition can be applied.

This coating composition was prepared by mixing 100 parts by weight of a water-soluble resin composition prepared by mixing 80% by weight of resorcinol diglycidyl ether and 20% by weight of propanol amine, And 1 to 10 parts by weight of hexamethylated-hexamethylol melamine.

In the present invention, by utilizing characteristics such as excellent chemical resistance and dimensional stability of resorcinol diglycidyl ether, corrosion resistance of propanolamine, and excellent lubrication characteristics of melamine derivatives, a more eco-friendly first connection line 41 And the second connection line 42 can be formed.

The method of applying such a coating composition for corrosion prevention is preferably applied to the surfaces of the first connection line 41 and the second connection line 42 such that the dry film thickness is 10 to 30 μm.

If the dry film thickness is less than 10 mu m, the service life can be shortened. If the dry film thickness is more than 30 mu m, there is no problem in function, but the economic advantage is reduced.

The first connection line 41 and the second connection line 42 coated with the coating composition for preventing non-woven fabric are air-dried for 10 to 30 minutes and then dried at 100 to 200 ° C, preferably at 150 to 180 ° C for 10 to 50 minutes It is possible to obtain a coating film which is non-sticky and excellent in gloss.

10: Gas injection valve
11: Sealed oil filled space
12: Controlled filling space
13: Cavity for airtight test
13-1: Test gas filling space
13-2: Task gas discharge line
13-3: Gas detection path
14: Spindle guide
20: Pump for forming hydraulic pressure
HL1: inlet line
21: Reservoir
HL2-1: first outlet line
HL2-2: second outlet side line
22: Sealing oil shutoff valve
23: Sealing oil pressure gauge
24: Sealing oil release valve
25: Electric switch
26: Solenoid valve
27: Pressure reducing valve
28: Controlled hydraulic pressure gauge
29: Controlled release valve
30: Gas booster
GL1: inlet line
31: Test gas supply container
GL2: Exit line
32: first gas shutoff valve
33: Gas pressure gauge
34: second gas shutoff valve
40: Air pressure source
41: first connection line
42: second connection line
43: first air regulator
44: Air pressure gauge
45: second air regulator

Claims (4)

A control oil filling space 12 for raising and lowering the internal spindle guide 14 and a test gas filling space 13-1 and a discharge line 13- A gas injection valve airtightness testing device for a gas engine for testing the airtightness of a gas injection valve (10) formed with an airtight test cavity (13) including a gas sensing path (13-3) sealed by a gasket, In this case,
A sealing oil filled in the sealing oil filled space 11 of the gas injection valve 10 and a hydraulic pressure forming pump for forming a control oil supply pressure for opening and opening the spindle guide 14 in the gas injection valve 10 20);
The gas booster 30 for directly supplying the test gas to the airtight test cavity 13 formed in the gas injection valve 10 is connected to the gas injection valve 10 so as to form a separate independent batch line;
The gas booster 30 is a kind of pump operated by the air pressure. The test gas supply vessel 31 is connected to the inlet line GL1 and the outlet line GL2 are mounted with a first gas shutoff valve 32, a gas pressure gauge 33 for measuring the gas pressure and a second gas shutoff valve 34 side by side;
The oil pressure forming pump 20 is an air driven liquid pump or an electric hydraulic pump operated by the air pressure. The inlet line HL1 is connected to a reservoir 21 filled with hydraulic oil for sealing oil and control oil And the first outlet side line HL2-1 connected to the sealing oil filled space 11 of the two outlet side lines HL2-1 and HL2-2 is connected with a sealing oil shutoff valve 22 and a sealing The hydraulic pressure gauge 23 and the sealing oil release valve 24 are mounted side by side and the second outlet side line HL2-2 connected to the control oil filled space 12 is provided with a solenoid A valve 26, a pressure reducing valve 27, a control hydraulic pressure gauge 28 and a control fluid release valve 29 are mounted side by side;
The hydraulic pressure forming pump 20 and the gas booster 30 are connected to one air pressure supply source 40 and connected to a first connection line 41 for connecting the hydraulic pressure forming pump 20 and the air pressure supply source 40 A first air regulator 43, an air pressure gauge 44 and a second air regulator 45 are connected to the second connection line 42 connecting the gas booster 30 and the air pressure supply source 40 ;
The surface of the sealing oil pressure gauge 23, the control hydraulic pressure gauge 28, the gas pressure gauge 33 and the air pressure gauge 44 is provided with an antifouling coating layer coated with a composition for antifouling coating, Wherein the composition for preventing application comprises boric acid and sodium carbonate in a molar ratio of 1: 0.01 to 1: 2, and the coating thickness of the anti-fouling coating layer is 500 to 2000 Å;
The first air regulator (43) and the second air regulator (45) are coated with a discoloring portion that changes color depending on the temperature, and the discoloring portion has two or more temperature discoloring materials whose color changes Is applied to the surfaces of the first air regulator (43) and the second air regulator (45) and separated into two or more sections according to the temperature change, so that it is possible to judge the temperature change stepwise, and the discoloration part A protective film layer is applied;
The first connection line 41 and the second connection line 42 are coated with an anti-corrosive coating layer of a coating composition comprising 80% by weight of resorcinol diglycidyl ether and 40% by weight of propanol 1 to 10 parts by weight of hexamethylated-hexamethylol melamine relative to 100 parts by weight of a water-soluble resin composition prepared by mixing 20% by weight of an amine (propanol amine) The first connection line 41 and the second connection line 42 to which the coating composition is applied are air dried for 10 to 30 minutes and then dried at 100 to 200 DEG C for 10 to 50 minutes Wherein the gas-injection-valve air-tightness testing device is configured to be cured. delete delete delete

Images