JPS63266332A - Aqueous solution for joining and testing joint of gas and waterworks conduit and method for joining and testing joint of gas conduit using said solution - Google Patents

Abstract

PURPOSE:To eliminate the laboriousness in a field work and to ease and simplify administration businesses by using one kind of aq. soln. essentially consisting of potash soap so that said soln. exhibits the functions and roles of both a lubricant and foaming agent. CONSTITUTION:The aq. soln. contg. the potash soap consisting of satd. fatty acid of <=14C prepd. from coconut oil fatty acid, nonionic water soluble high- polymer material such as methyl cellulose, sequestering agent such as ethylenediaminetetraacetic acid 4Na, and nonionic surfactant such as polyoxyethylene alkyl ether as solutes is used as the aq. soln. for joining and testing. An NBR gasket is inserted between conduits 1 and 2 and a flange 5 on the conduit 2 side is fixed by means of a retaining ring 6 and bolts 7 at the time of joining said conduits. The above-mentioned soln. is used in 20-100wt.% concn. as the lubricant at the time of inserting the NBR gaskets 3, 4 between said conduits. This sq. soln. is used in 0.2-20wt.% concn. as a foaming liquid for the airtight test of gas conduits.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an aqueous solution for joining and testing gas and water pipe joints and a method for joining and testing gas pipe joints using the same.

<Conventional technology> Most gas and water pipes are buried pipes, and the joints of these pipes are fully capable of dealing with road surface loads, vibrations, and other unforeseen stress loads from multiple angles. However, gaskets with a structure that does not leak gas or water are used, and the gasket material has excellent aging resistance, chemical resistance, water resistance, etc., and mechanical properties such as tensile strength, anti-foam elasticity, and rigidity. NBR is generally widely used because of its high reliability in terms of its digital properties.

FIG. 1 is a diagram showing a general conduit joint structure using a conduit as an example for explaining both the present invention and the conventional art.

When joining conduit 1.2, use an NBR gasket' (
A round rubber 3 and a square rubber 4) shown in the figure are inserted, and the flange 5 on the conduit 2 side is fixed with a press ring 6 and bolts 7. And, on the surface of this NBR gasket 3.4, there is a "
Apply lubricant and insert.

In this way, the friction between the gasket 3.4 and the conduit 1.2 is reduced and the gasket 3.4 is inserted smoothly.The usual method is to use a water-soluble polymer solution or a detergent solution as a "lubricant". Traditionally used. In addition, in the figure,
8 indicates a Teflon retaining ring.

In addition, "foaming liquid J" has been used for airtightness testing of gas pipe joints for gases such as city gas, propane gas, and even Freon gas for air conditioning. It is used by diluting it with water.As for the type and composition of the "foaming liquid," it may be used by dissolving granular detergent, but in general, liquid detergent is easier to handle. Since then, it has been widely used.

<Problems to be Solved by the Invention> Currently, when considering the lubricant used when joining gas/water pipe joints and the foaming agent for airtightness testing for gas pipe joints from the standpoint of rationalization and technical improvement, it is difficult to find practical solutions. , many problems that need to be resolved are enumerated.

First of all, ``When joining joints of gas and water pipes, the water-soluble polymer solution of the existing lubricant is
When inserting a gasket made of R, the effect of reducing slip resistance is not sufficient, and there are cases where the operation is not smooth and causes a delay in the joint joining operation. Therefore, there has been a demand for the development of a new lubricant that fully satisfies various requirements for on-site work, such as good sliding performance, ease of application, and easy removal of excess deposits. there were.

Secondly, it is necessary to prepare two types of agents, a lubricant and a foaming agent, when fitting the "gas" conduit. To do this, different types of chemicals must be applied and prepared each time at the gas pipeline construction site. Continuously having auxiliary materials with different total heat compared to conduit materials, etc., including purchasing and storing them, is a rather complicated business, and a certain amount of expenses must be accounted for.

Means for Solving the Problems> The present invention has been made to solve the above problems, and the aqueous solution for joining and testing gas/water pipe joints according to the first invention has a carbon number Potassium soap consisting of 14 or less saturated fatty acids, a nonionic water-soluble polymer substance, a sequestering agent,
The method for joining and testing a gas pipe joint according to the second invention comprises aqueous solution containing a nonionic surfactant as a solute. An aqueous solution containing a water-soluble polymer substance, a sequestering agent, and a nonionic surfactant as solutes is used as a lubricant for joining gas pipe joints at a concentration of 20 to 100 wt%, and the concentration is 0.2' to 100% by weight. It is used as a foaming liquid for gas conduit "airtight test angle" at 20% and 1t%.

As the "potassium soap made of a saturated fatty acid having 14 or less carbon atoms", those prepared from coconut oil fatty acids are suitable.

Suitable examples of the "nonionic water-soluble polymeric substance" include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, and polyethylene glycol.

As a “sequestering agent”, ethylenediaminetetraacetic acid 4
Preferred are Na, 3Na hydroxyethyltriacetate, 3Na nitrilotriacetate, and the like.

Suitable examples of the "nonionic surfactant" include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, alkylamine oxide, fatty acid alkanolamide, and the like.

In addition, the composition ratio of each component in the above solute (total 100
wt%) is preferably in the following range.

・Potassium soap ・−−−−−1−−−−・−・−・−
・・60～95%1t%・Nonionic water-soluble polymer substance・・・1～10wt%・Sequestering agent・---
−−−−・−・−・−・−１１１−・−・−・1～10
wt%・Nonionic surfactant---1-・----1・
-・-------・-・1 to 30-1% And in the second invention, the solute having this composition is used at a concentration of 20 to 50%.
It is particularly preferable to use it as a lubricant for joining gas pipe joints at a concentration of 0.2 to 5% by weight and as a foaming liquid for gas pipe tightness tests at a concentration of 1 t%.

<Function> Potassium soap solution is generally prepared from coconut oil fatty acids, and since this fatty acid contains some double bonds, it is easily oxidized in the air, and is oxidized by molecular oxygen to form peroxides. generate. This peroxide normally causes deterioration of synthetic rubbers such as SBR (styrene butadiene rubber) and NBR in addition to natural rubber, but in the case of the present invention, it has no effect on the durability of rubber. Since potassium soap consisting only of a group of saturated fatty acids having 14 or less carbon atoms, which does not cause deterioration, is used, it is possible to prevent deterioration of NBR gaskets and the like and contribute to improving durability.

The aqueous solution according to the first invention can be used as a "lubricant" or "foaming agent" depending on its concentration, so it can be used as a lubricant for joining gas and water pipes with excellent sliding properties, and a foaming test for gas pipe joints. (1) A lubricant/foaming agent liquid that can be used in gas pipe fittings depending on the concentration.

Similarly, the joining/testing method according to the second invention fundamentally reforms the current state of joining/testing methods for gas pipe joints that require a lubricant and a foaming agent, and uses one type of jointing/testing method mainly consisting of potassium soap. An aqueous solution is used to perform both of these functions and roles. In other words, the solute is used as a "lubricant" at a concentration of 20 to 100% and 1 t% relative to the solvent (water), and at the same time, this aqueous solution is Further, it is diluted with tap water or the like to a concentration of 0.2 to 20 wt% and immediately used as a "foaming liquid." By adopting this method, the complexity that has traditionally been pointed out in on-site work has been resolved, and by integrating lubricants and foaming agents, purchasing,
Management operations, including storage and transportation, are also greatly simplified and simplified, which naturally contributes to significant cost reductions.

In addition, problems associated with the use of existing lubricant water-soluble polymer solutions that have been pointed out in the past, such as difficulty in spreading and difficulty in removing excess deposits, have also been addressed.
This is something that can be easily resolved.

<Embodiments> Preferred embodiments of this invention (first invention and second invention) will be described below. First, the following Examples 1 to 3 show the method for producing potassium soap solutions (aqueous solutions) A to C according to the present invention,
Next, test results of the potassium soap solutions A to C will be shown, and comparative examples of potassium soaps and H other than those of the present invention will be shown in order.

□Production method□ Coconut oil fatty acid is hydrogenated under pressure in the presence of a nickel catalyst. After removing the catalyst etc. from the reaction product,
A lauric acid-rich fraction was obtained by distillation under reduced pressure. The composition of this saturated fatty acid fraction is 75% lauric acid and 15% myristic acid.
%, and 10% capric acid, and its acid value is 28
0, and the iodine value was 0.3. This saturated fatty acid was prepared as a common raw material fatty acid for Examples 1' to 3.

Next, 100mj of boiling water at about 70℃! 6 g of hydroxypropyl cellulose (nonionic water-soluble polymer substance),
Add the potassium hydroxide solution gradually while stirring, and after thoroughly and homogeneously dispersing it, add 400 m2 of tap water at room temperature to completely dissolve it. After heating this aqueous solution to 80°C, add the potassium hydroxide solution. (50%) was added, and then 270 g of the above fatty acid was added and reacted. Then, add 20g of ethylenediaminetetraacetic acid/4Na (sequestering agent), and 20g of polyoxyethylene alkyl ether (nonionic surfactant), stir until it becomes transparent and dissolve, making the total volume 1000m2. After adding tap water up to the temperature, the mixture was allowed to cool.

In this way, potassium soap solution A was prepared.

When the components of this potassium soap solution A were investigated, they were as follows.

Solute 36.7wt% (ratio of each component in the solute) ・Potassium soap ・−・−・・−・−・−・−
・−・−・−87.47wt%・Nonionic water-soluble polymer substance・−・−・・−・1.63wt%・Sequestering agent・・−−−−−−−−−−・・・・・・－－－－－
−−−−−・・・−・−・・5.45wt%・Nonionic surfactant・−−−1−−・−・・−−1−−−
-----・5.45wt%? ” 63.3
wt%・------・In other words, concentration 36.7sv
t% aqueous solution.

100 mj of boiling water at about 70°C! While stirring, 2 g of hydroxypropyl cellulose (nonionic water-soluble polymer substance) was gradually added to the solution, and after thoroughly and homogeneously dispersed, 300 mf of tap water at room temperature was added to completely dissolve it. . After heating this aqueous solution to 80°C, 138 g of potassium hydroxide solution (50%) was added, and then the above fatty acid 24
5g was added and reacted. Then, add 20 g of ethylenediaminetetraacetic acid/4Na (sequestering agent) and 100 g of a 30% solution of lauryl amine oxide (nonionic surfactant) and stir until it becomes transparent to dissolve it, making the total volume 1000 ml. After adding tap water up to the temperature, the mixture was allowed to cool. In this way, potassium soap solution B was prepared.

When the components of this potassium soap solution B were investigated, they were as follows.

Solute 34.4wt% (ratio of each component in the solute) ・Potassium soap・・−−−−−−−−−・−・−・−
m-------・----84,88 t%・Nonionic water-soluble polymer substance・---0,58wt
%・Sequestering agent・・−−−−−−1・−−−−−1−・
−−−−−−−−・・−・・−−〜−−・・5.82w
t%・Non-ionic surfactant・−−−−−−−・−・・
−・・・・・−1−−−−−・8.72wt%″
Water 65.6 ivt% - In other words, the aqueous solution had a concentration of 34.4 wt%.

400 mj of room temperature tap water! While stirring, 2 g of hydroxyethyl cellulose (a nonionic water-soluble polymeric substance) was gradually added to the solution and dissolved until it became transparent. This aqueous solution was heated to 80°C, and a potassium hydroxide solution (50%) was added.
138 g was added, and then 245 g of the above fatty acid was added and reacted. Then, ethylenediaminetetraacetic acid 4
Add 20 g of Na (sequestering agent) and 30 g of lauric acid jetanolamide (nonionic surfactant),
Stir until it becomes transparent and dissolve, making the total amount 10100.
O! After adding tap water until it reached , it was allowed to cool.

In this way, potassium soap solution C was prepared.

When the components of this potassium soap solution C were investigated, they were as follows.

'l' 34.4 wt% (proportion of each component in the solute) ・Potassium soap ・・−・−−−−−−−−−−・
-----------84,88wt%・Nonionic water-soluble polymer substance-----1--・0.58w
t%・Sequestering agent・−−−−−−−−−−−−−−−
−−−−−−−−−−−−−−−−−−−−−−−−−
5,82wt%・Nonionic surfactant・−・−・−・−
-------・-・-・8.72 days t% medium 65.
6 wt% ---------- In other words, the aqueous solution had a concentration of 34.4 wt%.

Test results The results of the slip resistance reduction effect test when used are shown below. The exam is
"Floor slip test method (pendulum type) JIS A1407" set for slip test of plastic flooring materials
-1963'', the performance as a lubricant was measured, and the results are shown in Table 1. This is a sheet (made of NBR) made of the same material (product number) as the NBR gasket shown in Fig.
A stainless steel plate with a thickness of 2III11) was prepared, and the resistance value was measured by sliding a stainless steel plate over the surface.

<Table 1> Slip test results of potassium soap solution and existing lubricant Material Slip resistance coefficient ゚) As is clear from this Table 1, potassium soap solution A-C has a slip resistance coefficient of 1/1 compared to existing lubricant (water-soluble polymer solution). It shows a low resistance value of about 2,
This proves that the performance as a lubricant is sufficient. In addition, as a result of measuring the viscosity of these potassium soaps A-C, the viscosity of existing lubricants was 5350 cp (20℃
) and is a fairly viscous liquid, whereas the liquid of the present invention has a viscosity of up to 700 cp (20°C) at most. This can be said to be resolved by

``1. Tests Next, we will present test results regarding the extremely important issue of corrosive properties of lubricants on gas and water pipe materials. In other words, "cast steel" is generally used as a material for gas and water pipes.
However, test solutions A, B, and C according to the present invention exhibited excellent corrosion resistance against these materials, as shown in Table 2 below. For this test, test pieces prepared from gas and water pipe materials (401II11×60mff1×
51ml11) was used. That is, 300 mi of each test solution! 500mj! The test piece was placed in a bottle with a stopper, and suspended using cotton thread so that 1/2 of the length of the test piece was immersed in the test solution. The bottle with this test piece suspended therein was transferred to an incubator and maintained at 40±2° C. for 168 hours (7 days) to conduct a corrosion test.

<Table 2> Corrosion test of undiluted solution The corrosivity of each test solution shown in Table 2 is shown in Table 2 as an average corrosion degree, and this is divided by the specific gravity of cast steel (7, 87) as the average corrosion degree. I raised it. That is, the degree of erosion of the potassium soap solution A-C of the present invention is 3 to 4 X 10-'co+
/7 days, showing perfectly excellent values.

The relationship between this degree of erosion and the evaluation criteria for corrosion resistance is shown in Table 3 below.

<Table 3> Evaluation criteria based on corrosion degree 1) Rank Erosion degree for 7 days Corrosion resistance evaluation Comparing this Table 3 with the test results in Table 2 above, potassium soap solutions A, B, and C were all ranked 1. It is clear that this corresponds to the evaluation of "complete corrosion resistance".

fimJ -f as " ゛ Next, the above-mentioned stock solution potassium soap A-C was diluted 50 times and 100 times with tap water, and the concentrations of each aqueous solution were as follows. Airtightness test for "gas pipe joints" It was used as a foaming liquid.

50x 100x Potassium Soap A 0.73wt% 0.37kgt
% Potassium soap B0.7wt% 0.35gt% Potassium soap C0.7wt% 0.35wt% 3 of the present invention
Potassium soap A-C is a combination of a water-soluble polymer substance, a sequestering agent, and a nonionic surfactant, so it effectively reduces the critical micelle concentration of the soap itself.
We succeeded in dramatically improving the surfactant ability of potassium soap at low concentrations.

As the existing foaming liquid, a commercially available kitchen synthetic acid detergent diluted 50 to 100 times has been commonly used, but it has been determined that dilution to this extent is appropriate for handling. The newly prepared potassium soap solutions A-C according to the present invention can be used without any inferiority compared to conventional foaming solutions even under these conditions of 50 to 100 times dilution, and have excellent foaming properties, especially foam stability. In this respect, we have found that it is actually superior to existing foaming liquids.

In other words, what is required of a foaming liquid for airtightness tests related to gas pipes is that, for example, when the foaming liquid is transferred to a large basin-shaped container and stirred to foam, it must have an abundance of dense and stable air bubbles. It is essential that these conditions are satisfied, and the bubbles must remain for a certain period of time during the operation of the airtightness test without breaking.

Table 4 below shows the comparison results of the foaming power test and foam stability test between the existing foaming agent (commercially available kitchen synthetic detergent A) and the potassium soap A-B diluted as a foaming agent as described above. and listed in Table 5.

Table 4: Foaming power test 1 Table 5: Foam stability test Based on the test results in Table 4, the foaming power of potassium soap solutions A to C is almost the same as that of commercial kitchen detergents. In Although,
On the other hand, the foam stability shown in Table 5 showed excellent results, and the amount of foam remaining after 30 minutes was close to 100%. In other words, it can be seen that the potassium soaps A-C of the present invention are more suitable for the airtightness test of conduits because the bubbles do not disappear easily.

Table 6 and Table 7 show the results of investigating the corrosivity of potassium soap A-C in diluted solutions (50 times and 100 times). The procedure was carried out in the same manner as in the case of lubricant).

<Table 6> Corrosion test of 50 times diluted liquid Soboa.

<Table 7> Corrosion test of 100 times diluted solution Regarding the experimental results of Tables 6 and 7, potassium soap solutions A-C of the present invention
In the case of , signs of cloudiness due to phase separation were observed due to dilution (50 times and 100 times), but no change in overall heat was observed in the color tone of the diluted solution. Comparing the degree of erosion in this experiment with the evaluation criteria for degree of erosion in Table 3, both were '7.0XIO-'cm: 'sufficient corrosion resistance'.
It was demonstrated that the corrosion resistance against gas pipe materials is more than twice as good.

Next, a comparative example will be shown.

Comparison ■Tap water 500mj! was heated to 80° C., 155 g of potassium hydroxide solution (50%) was added, and then 270 g of the same fatty acid as in the previous example was added for reaction. Then, 5 g of ethylenediaminetetraacetic acid/4Na (sequestering agent) was added, and the mixture was stirred and dissolved until it became transparent.
Tap water was added until the temperature reached 100O, and then it was cooled. In this way, potassium soap solution D (soap concentration 32%) was prepared. That is, eight rounds of potassium soap solution containing no nonionic water-soluble polymeric substance and nonionic surfactant were prepared.

This potassium soap liquid has a hardness of 10100 (CaCOs
When diluted by 15 times or more with pp tap water, formation and sedimentation of metal soap were observed, and as a matter of course, a significant decrease in foaming performance was observed.

``This I day'' Kame room temperature tap water 400mj! While stirring, 2 g of hydroxycellulose (a nonionic water-soluble polymer substance) was gradually added to the solution, and the solution was completely dissolved until it became transparent. This aqueous solution was heated to 80°C, and a potassium hydroxide solution (50%) was added.
Add 132 g of hydrogenated coconut oil fatty acids (48% lauric acid, 20% myristic acid, 11% stearic acid, 10% valmitic acid, 6% capric acid and 5% capric acid).
%) was added, stirred until it became transparent to dissolve it, tap water was added until the total amount became 1000 mf, and then cooled. In this way, potassium soap solution E (soap concentration 29%) was prepared.

That is, a potassium soap solution E@ containing no sequestering agent and nonionic surfactant was prepared.

In the case of this potassium soap solution E, when the stone concentration was increased to 30% or more, it solidified at room temperature. In addition, the low-temperature stability of the diluted solution is poor, for example, when diluted 10 times or more, phase separation occurs already at 10'C.
Formation of acidic soap precipitates was observed, and foaming performance was also significantly reduced.

As shown in the above Examples and Comparative Examples, the potassium soap solutions A-C presented in the present invention are compared with existing lubricants (water-soluble polymer solutions) when used as lubricants for joining gas and water pipe joints as undiluted solutions. This lubricant has a small slip resistance coefficient and exhibits excellent sliding performance.At the same time, by diluting this lubricant with tap water, etc., it can be immediately used as a foaming liquid for airtightness tests for gas pipe joints. Furthermore, compared to synthetic kitchen detergents that have traditionally been used, it is possible to secure a rich amount of foam that is stable over time.
It has many characteristics such as being highly effective as a foaming agent and being less corrosive to metals. By using the present invention based on these surprising discoveries, it can be said that the industrial effect exerted in gas/water pipe joint joint joining work and airtightness testing of gas pipe joints is extremely large.

<Effects> This invention (the first invention and the second invention) has the content as explained above, and therefore uses a lubricant used when inserting a gasket and a gas pipe as essential chemicals when joining joints of gas and water pipes. Solving the conventional problem of having to prepare two types of foaming agents for airtightness testing after bonding, we now offer a method that can serve both purposes by preparing only one type of aqueous solution. It's about doing. As a result, it is possible to improve and streamline the complexity of construction work sites where two types of auxiliary drugs, which are different from the pipe materials, are constantly kept separately.
This can be said to greatly contribute to cost savings, including storage, transportation, etc. This contributes to the rationalization of piping work for gas and water pipes in general, and its industrial effects are also worth mentioning.

In addition, by using an aqueous solution with a certain concentration as a stock solution as a lubricant for joining joints of gas and water pipes, problems that have been pointed out with conventional lubricants, namely, the effect of reducing gasket slip resistance is not sufficient. It solves various problems such as difficulty in applying it to the gasket surface and difficulty in removing excess adhesion, and is extremely effective as a lubricant and easy to handle, contributing to improved work when joining pipe joints. In fact, it can be said that it is a huge amount.

Furthermore, since the stock solution is diluted and used as a foaming solution for gas pipe joint test stations, it has sufficient surfactant ability even in the extremely low concentration range (for example, potassium soap concentration of 0.5 wt% or less). We were able to prepare an aqueous solution, and as a result, we were able to prepare a foaming liquid with outstanding foam stability compared to existing commercially available synthetic kitchen detergents. the result,
This made it possible for the first time to integrate the lubricant and foaming agent, which was the original goal.

In addition, a particularly noteworthy feature of the present invention is that the aqueous solution used in the present invention exhibits almost no corrosive effect on gas and water pipe materials. This is an extremely important and useful finding.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a joining structure of a conduit joint for explaining the present invention and the conventional art. 1.2 ・−・ Conduit 3 −・ Round rubber (gasket) 4 ・−・ Square rubber (gasket) 5 ・−・ Flange 6 ・−・ Push ring 7 ・−・ Bolt 8 −・ Teflon retaining ring

Claims (2)

[Claims] (1) Potassium soap made of saturated fatty acid having 14 or less carbon atoms, a nonionic water-soluble polymer substance, and a sequestering agent,
An aqueous solution for joining and testing gas and water pipe joints, consisting of an aqueous solution containing a nonionic surfactant as a solute. (2) a potassium soap made of a saturated fatty acid having 14 or less carbon atoms, a nonionic water-soluble polymer substance, a sequestering agent,
An aqueous solution containing a nonionic surfactant as a solute is used at a concentration of 20 to 100 wt% as a lubricant for joining gas pipe joints, and at a concentration of 0.2 to 20 wt% as a foaming liquid for gas pipe airtightness tests. Joining of gas pipe joints characterized by
Test method.