JPH0334822B2 - - Google Patents
Info
- Publication number
- JPH0334822B2 JPH0334822B2 JP58220242A JP22024283A JPH0334822B2 JP H0334822 B2 JPH0334822 B2 JP H0334822B2 JP 58220242 A JP58220242 A JP 58220242A JP 22024283 A JP22024283 A JP 22024283A JP H0334822 B2 JPH0334822 B2 JP H0334822B2
- Authority
- JP
- Japan
- Prior art keywords
- buried pipe
- defect
- test piece
- defective part
- ground
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000002950 deficient Effects 0.000 claims description 44
- 230000007547 defect Effects 0.000 claims description 34
- 238000012360 testing method Methods 0.000 claims description 31
- 230000007797 corrosion Effects 0.000 claims description 27
- 238000005260 corrosion Methods 0.000 claims description 27
- 238000000034 method Methods 0.000 claims description 20
- 239000011248 coating agent Substances 0.000 claims description 16
- 238000000576 coating method Methods 0.000 claims description 16
- 238000005259 measurement Methods 0.000 claims description 16
- 230000005611 electricity Effects 0.000 claims description 4
- 238000010586 diagram Methods 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 4
- 238000009412 basement excavation Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 238000012423 maintenance Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000009933 burial Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
- G01N17/02—Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
Description
【発明の詳細な説明】
本発明は、塗覆装埋設管の被覆欠陥測定方法に
関するもので、さらに詳言すれば、塗覆装埋設管
の保守・管理を良好にかつ安全に達成することを
目的とするものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring coating defects in coated buried pipes, and more specifically, to achieve good and safe maintenance and management of coated buried pipes. This is the purpose.
埋設配管については、塗覆装による防食を行つ
ているのが一般である。 For buried pipes, corrosion protection is generally performed by coating them.
この塗覆装埋設配管の塗覆装に欠陥部があるよ
うな場合、この欠陥部から腐食を生じ、この埋設
配管による流体輸送に障害を生じることになる。 If there is a defective part in the coating of the coated buried pipe, corrosion will occur from the defective part, which will impede fluid transport through the buried pipe.
そこで、塗覆装埋設配管の塗覆装の欠陥部を探
知し、この欠陥部の面積ならびに腐食電流量から
管体寿命を知ることが可能ならば、塗覆装埋設配
管の維持・管理上、非常に有用であり、さらに入
取替とか管体修理等についても、その費用を大幅
に低減出来る。 Therefore, if it is possible to detect defects in the coating of coated underground pipes and determine the lifespan of the pipe from the area of the defective parts and the amount of corrosion current, it would be possible to improve the maintenance and management of coated buried pipes. It is very useful and can also significantly reduce the cost of replacement and pipe repair.
従来の欠陥部探知法には、欠陥部の大きさや腐
食電流を地上測定によつて知る方法がないため、
腐食による貫通孔生成により深刻な事態の予想さ
る箇所では、掘削による直接調査が行われること
になり、多大な時間と労力そして機材とを必要と
していた。 With conventional defect detection methods, there is no way to know the size of the defect or corrosion current through ground measurements.
In areas where a serious situation is expected due to the formation of through holes due to corrosion, direct investigation by excavation is required, which requires a great deal of time, labor, and equipment.
このため、塗覆装埋設管の塗覆装の欠陥部を地
上から検出が出来ると共に、この欠陥部の大き
さ、ならびに腐食の進行程度をも知ることが出来
る手段の出現が強く望まれていた。 For this reason, there was a strong desire for a method that would be able to detect defects in the coating of coated buried pipes from the ground, as well as determine the size of these defects and the degree of corrosion. .
本発明は、上記した従来例の欠点を解消すると
共に従来からの要望を満たすべく創案されたもの
で、塗覆装埋設配管の塗覆装欠陥部と全く同じ腐
食条件下に置かれたテストピースの対地電位およ
び腐食電流を知ることによつて、塗覆装埋設配管
の塗覆装の欠陥部の有無およびその大きさ、さら
には腐食の進行程度の予測を知るようにしたもの
である。 The present invention was devised to solve the above-mentioned drawbacks of the conventional example and to satisfy the conventional demands. By knowing the potential to the ground and the corrosion current, it is possible to predict the presence or absence of defects in the coating of coated buried pipes, their size, and the extent to which corrosion will progress.
以下、本発明を図面を参照しながら説明する。 Hereinafter, the present invention will be explained with reference to the drawings.
塗覆装埋設配管の塗覆の欠陥の有無を探知する
方法としては、ピアソンサーベイに代表される如
く、大地から管体へ通電し、管上に現れる電位勾
配を探知する方法が一般的であり、現在の各種の
探知方法の殆どは、この原理に基づいている。 A common method for detecting defects in the coating of coated buried pipes is to pass electricity from the ground to the pipe body and detect the potential gradient that appears on the pipe, as typified by the Pearson survey. Most of the current detection methods are based on this principle.
本発明方法は、上記した方法の内の針電極によ
る地表面電位勾配測定を利用している。 The method of the present invention utilizes ground surface potential gradient measurement using a needle electrode among the methods described above.
第１図は、この測定方法の概念図であり、第２
図は、計測結果の一例である。 Figure 1 is a conceptual diagram of this measurement method, and the second
The figure shows an example of the measurement results.
第１図において、１は塗覆装を施した埋設配管
で、この埋設配管１の適当な箇所に欠陥部１ａが
形成されている。 In FIG. 1, reference numeral 1 denotes a coated buried pipe, and defective portions 1a are formed at appropriate locations on the buried pipe 1.
この埋設配管１に、電流２を介して電気的に接
続された接地電極５を通して通電を行う。 This buried pipe 1 is energized through a ground electrode 5 electrically connected via a current 2.
この接地電極５を通して埋設配管１に断続して
通電を行つた状態のまま、埋設配管１に沿つて大
地電位勾配測定用電圧計４の検出電極７を地表上
で移動させて、通電断続時の地表面電位差を、配
管上の地表を順次切れ目なく測定すると、この埋
設配管１の地表上の大地電位勾配は、第２図のよ
うになる。 While the buried pipe 1 is intermittently energized through the ground electrode 5, the detection electrode 7 of the earth potential gradient measurement voltmeter 4 is moved on the ground surface along the buried pipe 1, and the If the ground surface potential difference is measured continuously on the ground surface above the pipe, the ground potential gradient on the ground surface of this buried pipe 1 will be as shown in FIG.
なお、第１図において、３は電圧計、６は照合
電極である。 In addition, in FIG. 1, 3 is a voltmeter, and 6 is a reference electrode.
この第２図に示す如く、埋設配管１に欠陥部１
ａが生じていると、埋設配管１の地表上の大地電
位勾配は、この欠陥部１ａに対抗する箇所で急激
な変化を示す。 As shown in FIG. 2, there is a defect 1 in the buried pipe 1.
When a occurs, the ground potential gradient on the ground surface of the buried pipe 1 shows a sudden change at a location opposing this defective portion 1a.
この時の電位変化VHは、次式で近似出来るこ
とが知られている。 It is known that the potential change VH at this time can be approximated by the following equation.
VH＝IH・ρ／2πD ……(1)
ここで、IHは欠陥部１ａに流れる電流、ρは
土壌抵抗率、Ｄは埋設配管１の埋設深さである。 VH=IH・ρ/2πD (1) Here, IH is the current flowing through the defective portion 1a, ρ is the soil resistivity, and D is the burial depth of the buried pipe 1.
ところで、VSを埋設配管１と地表面との間の
電位差とし、rHを欠陥部１ａの等価半径とする
と、
IH＝VS・2πrH／ρ ……(2)
であるので、
rH＝DVH／VS ……(3)
となるが、この方法では、電位差VSを正確に求
めることが出来ないので、算出された等価半径
rHの値はあまり正確であるとは言えない。 By the way, if VS is the potential difference between the buried pipe 1 and the ground surface, and rH is the equivalent radius of the defective part 1a, then IH=VS・2πrH/ρ...(2), so rH=DVH/VS... ...(3) However, since it is not possible to accurately determine the potential difference VS with this method, the calculated equivalent radius
The value of rH cannot be said to be very accurate.
そこで、本発明は、第３図に示す如く、さらに
欠陥部１ａの形成する大地電位勾配と互いに作用
し合わない至近距離の埋設配管１の近傍に、疑似
欠陥部としてのテストピース９（裸の鋼片）を、
埋設位置させ、このテストピース９を絶縁リード
線によつて電流計８を介して埋設配管１に接続す
ることによつて、このテストピース９における大
地電位変化に従つて、等価半径rHを正確に算出
するのである。 Therefore, as shown in FIG. 3, the present invention further provides a test piece 9 (a bare piece) as a pseudo defective part in the vicinity of the buried pipe 1 at a close distance that does not interact with the ground potential gradient formed by the defective part 1a. steel pieces),
By placing the test piece 9 in a buried position and connecting it to the buried pipe 1 via an insulated lead wire and an ammeter 8, the equivalent radius rH can be accurately determined according to the change in ground potential at the test piece 9. It is calculated.
すなわち、本発明による塗覆装埋設管の被覆欠
陥測定方法は、塗覆装埋設管１に、別に設置した
接地極５から大地を通して通電している状態で、
針電極法により前記埋設管１の被覆欠陥部１ａを
測定探知すると共に、この欠陥部１ａの形成する
大地電位勾配と互いに作用し合わない前記欠陥部
１ａの近傍に、通電表面面積の既知なテストピー
ス９を設置し、このテストピース９を前記埋設管
１に電気的に接続して、このテストピース９を疑
似欠陥部として前記欠陥部１ａと同様の測定を行
つて前記した実在の欠陥部１ａとの測定値比較を
することによつて、実在する欠陥部１ａの面積を
検知するのである。 That is, the method for measuring coating defects in coated buried pipes according to the present invention involves applying electricity to the coated buried pipe 1 through the earth from a separately installed ground electrode 5.
In addition to measuring and detecting the coating defect 1a of the buried pipe 1 using the needle electrode method, a known current-carrying surface area test was carried out in the vicinity of the defect 1a that does not interact with the ground potential gradient formed by the defect 1a. A piece 9 is installed, this test piece 9 is electrically connected to the buried pipe 1, and the test piece 9 is used as a pseudo-defect part and the same measurement as the defect part 1a is performed to determine the actual defect part 1a. By comparing the measured values with the actual defective portion 1a, the area of the existing defective portion 1a is detected.
第３図の如くテストピース９を設置すると、欠
陥部１ａと同様に地表面上から測定した電位に第
４図に示したような変化が発生する。 When the test piece 9 is installed as shown in FIG. 3, a change as shown in FIG. 4 occurs in the potential measured from above the ground surface, similar to the defective portion 1a.
この電位変化のうちテストピース９に対応して
発生した電位変化分をVTとすると
VT＝IT・ρ／2πD ……(4)
となる。ここで、ITはテストピース９に流れる
電流である。 If the potential change generated corresponding to the test piece 9 out of this potential change is VT, then VT=IT・ρ/2πD (4). Here, IT is the current flowing through the test piece 9.
それゆえ、(1)式と(4)式とから、
IH＝IT・VH／VT ……(5)
が得られ、欠陥部１ａに流れる電流を確定するこ
とが出来、またテストピース９の等価有効半径を
rTとすれば、
IT＝VS・2πrT／ρ ……(6)
であるので、(2)式と(6)式とより、
rH＝rT・IH／IT ……(7)
が得られるので、欠陥部１ａの等価半径を確定す
ることが出来る。 Therefore, from equations (1) and (4), IH=IT・VH/VT...(5) can be obtained, the current flowing through the defective part 1a can be determined, and the equivalent value of the test piece 9 can be determined. effective radius
If rT, then IT=VS・2πrT/ρ...(6), so from equations (2) and (6), we get rH=rT・IH/IT...(7), so, The equivalent radius of the defective portion 1a can be determined.
また、テストピース９を流れる腐食電流の大き
さと、テストピース９である鋼片の単位腐食量と
から前記欠陥部１ａにおける腐食程度および腐食
の進行程度を予測することが出来る。 Further, the degree of corrosion and the degree of progress of corrosion in the defective portion 1a can be predicted from the magnitude of the corrosion current flowing through the test piece 9 and the unit corrosion amount of the steel piece that is the test piece 9.
すなわち、埋設管１に、別に設置した接地電極
５から大地を通して通電している状態で、針電極
法により前記埋設管１の被覆欠陥部１ａを測定探
知すると共に、この欠陥部１ａの形成する大地電
位勾配と互いに作用し合わない前記欠陥部１ａ近
傍に、通電表面面積の既知なテストピース９を設
置し、このテストピース９を前記埋設管１に電気
的に接続して、このテストピース９を疑似欠陥部
として、前記欠陥部１ａと同様の測定を行つて前
記した実在の欠陥部１ａとの測定値比較をするこ
とによつて、実在する欠陥部１ａの面積を検知
し、さらに前記テストピース９に電流計８を接続
すると共に前記接地局５かの通電を停止した状態
で、前記テストピース９からの腐食電流ITを前
記電流計８により計測して前記欠陥部１ａに流れ
る腐食電流IHを求めるのである。 That is, while electricity is being applied to the buried pipe 1 through the earth from a separately installed ground electrode 5, the coating defect 1a of the buried pipe 1 is measured and detected by the needle electrode method, and the ground formed by this defect 1a is detected. A test piece 9 with a known current-carrying surface area is installed near the defective portion 1a that does not interact with the potential gradient, and this test piece 9 is electrically connected to the buried pipe 1. As a pseudo defective part, the area of the actual defective part 1a is detected by performing the same measurements as the defective part 1a and comparing the measured values with the actual defective part 1a, and then 9 and with the earthing station 5 de-energized, the corrosion current IT from the test piece 9 is measured by the ammeter 8, and the corrosion current IH flowing to the defective part 1a is determined. I ask for it.
これを具体的に説明するならば、前記した手法
によつて欠陥部１ａの等価半径rHを確定するこ
とが出来たならば、電源２の電流を切つて埋設配
管１を原状態に復帰させてから、テストピース９
を流れる腐食電流ITcを計測すれば、
ITc＝VN・2πrT／ρ ……(8)
但し、VNは原状態における欠陥部１ａと大地
間の電位差である。 To explain this concretely, once the equivalent radius rH of the defective part 1a has been determined by the method described above, the current of the power supply 2 is cut off and the buried pipe 1 is returned to its original state. From, test piece 9
If the corrosion current ITc flowing through is measured, ITc=VN・2πrT/ρ...(8) However, VN is the potential difference between the defective part 1a and the ground in the original state.
なる関係があり、欠陥部１ａを流れる腐食電流
IHcもまた、
IHc＝VN・2πrH／ρ ……(9)
なる関係があるから、
IHc＝ITc・rH／rH ……(10)
となつて、欠陥部１ａの腐食電流IHcを確定する
ことが出来る。There is a relationship such that the corrosion current flowing through the defective part 1a
IHc also has the following relationship: IHc=VN・2πrH/ρ...(9), so IHc=ITc・rH/rH...(10), and the corrosion current IHc of the defective part 1a can be determined. I can do it.
以上の手段によつて、埋設配管１の欠陥部１ａ
の有無、位置、大きさそして腐食電流IHcを地表
面上での計測によつて知ることが出来る。 By the above means, the defective part 1a of the buried pipe 1
The presence, location, size, and corrosion current IHc of corrosion can be determined by measuring them on the ground surface.
鋼の腐食量Ｗは、9.1ｇ／ｍＡ・Yrで表され、
また鋼の比重は7.86であるので欠陥部１ａの腐食
浸食深さをｄとし、浸食係数その他をＫとすれ
ば、腐食浸食深さｄは、
ｄ＝KW／πrH・rH
＝9.1KIHcYr／7.86πrH・rH ……（11）
となる。 The corrosion amount W of steel is expressed as 9.1g/mA・Yr,
Also, since the specific gravity of steel is 7.86, if the corrosion depth of the defective part 1a is d, and the erosion coefficient and other values are K, then the corrosion depth d is: d=KW/πrH・rH=9.1KIHcYr/7.86πrH・rH...(11)
従つて、上記した欠陥部１ａの等価半径rHお
よび欠陥部１ａを流れる腐食電流IHcの測定結果
の数値を（11）式に適用すれば、埋設配管１の使
用年数Yrが判つていさえすれば、測定時点にお
ける腐食浸食深さを推定することが出来る。 Therefore, by applying the values of the measurement results of the equivalent radius rH of the defective part 1a and the corrosion current IHc flowing through the defective part 1a to equation (11), as long as the service life Yr of the buried pipe 1 is known, , it is possible to estimate the corrosion depth at the time of measurement.
また、埋設配管１の管厚さｗが判つていれば、
埋設配管１の管壁に腐食により、貫通孔が生成さ
れるまでの年数YRは、
YR＝7.86（ｗ−ｄ）πrH・rH／9.1KIHc
から正確に算出することが出来、これによつて貫
通孔生成までの期間をほぼ正確に予測することが
出来ることになる。 Also, if the pipe thickness w of the buried pipe 1 is known,
The number of years YR until a through hole is formed due to corrosion in the pipe wall of buried pipe 1 can be accurately calculated from YR = 7.86 (w - d) πrH・rH / 9.1KIHc. This means that the period until pore formation can be predicted almost accurately.
第５図に示すように、接地電極５を電源２およ
び電流計を介して埋設配管１に接続すると共に、
テストピース９を電流計８およびスイツチＳを介
して埋設配管１に接続し、接地電極５を通して埋
設配管１に断続して通電を行つた状態のまま、埋
設配管１に沿つて大地電位勾配測定用電圧計４の
検出電極７を地表上で移動させて、通電断続時の
地表面電位差を、埋設配管１上の地表を順次切れ
目なく測定し、第６図に示す埋設配管１の地表上
の大地電位勾配結果を得た。 As shown in FIG. 5, the ground electrode 5 is connected to the buried pipe 1 via the power source 2 and the ammeter, and
The test piece 9 is connected to the buried pipe 1 via the ammeter 8 and the switch S, and while the buried pipe 1 is intermittently energized through the ground electrode 5, the test piece 9 is connected to the buried pipe 1 via the ammeter 8 and the switch S, and the ground potential gradient is measured along the buried pipe 1. The detection electrode 7 of the voltmeter 4 is moved on the ground surface, and the ground surface potential difference during energization and intermittent periods is sequentially and seamlessly measured on the ground surface above the buried pipe 1. Potential gradient results were obtained.
第１の実測では、深さ1.5ｍに埋設された埋設
配管１に対して、通電表面面積が５cm2（2rT＝
2.52cm）のテストピース９を用い、スイツチＳを
オンさせた時のテストピース９への流入電流ITは
12ｍＡであり、テストピース９での大地電位勾配
の変化量VTは120ｍＶ、埋設配管１に対向した一
部で55ｍＶの変化量VHが測定され、埋設配管１
に被覆欠陥部１ａが生じている可能性が認められ
た。 In the first actual measurement, the current-carrying surface area of the buried pipe 1 buried at a depth of 1.5 m was 5 cm 2 (2r T =
Using the test piece 9 (2.52 cm), the inflow current I T into the test piece 9 when switch S is turned on is
12 mA, the amount of change V T in the ground potential gradient at test piece 9 is 120 mV, and the amount of change V H of 55 mV is measured in the part facing buried pipe 1.
It was recognized that the coating defect 1a may have occurred.
そこで、これらの計測結果を(5)式に代入する
と、欠陥部１ａに流れる電流IHは、
IH＝IT・VH／VT
＝12ｍＡ・55ｍＶ／120ｍＶ＝5.5ｍＡ
さらに、(7)式から欠陥部１ａの等価半径rHを求
めると、
rH＝rT・IH／IT
＝1.26cm・5.5ｍＡ／12ｍＡ＝0.58cm
となり、欠陥部１ａの直径2rHは1.16cmと算出さ
れた。 Therefore, by substituting these measurement results into equation (5), the current I H flowing through the defective part 1a is: I H = I T · V H /V T = 12 mA · 55 mV / 120 mV = 5.5 mA Furthermore, (7) Determining the equivalent radius r H of the defective part 1a from the formula, r H = r T・ I H / I T = 1.26 cm 5.5 mA / 12 mA = 0.58 cm, and the diameter 2r H of the defective part 1a is calculated as 1.16 cm. It was done.
掘削して埋設配管１を調査した結果、大地電位
勾配が変化した近傍で直径1.3cmの欠陥部１ａが
見つかり、算出値とかなり良く合致した。 As a result of excavating and investigating the buried pipe 1, a defect 1a with a diameter of 1.3 cm was found in the vicinity of the change in the ground potential gradient, which agreed fairly well with the calculated value.
第２の実測では、深さ0.75ｍに埋設された埋設
配管１に対して、通電表面面積が１cm2（2rT＝
1.13cm）のテストピース９を用い、スイツチＳを
オンさせた時のテストピース９への流入電流ITは
2.56ｍＡであり、テストピース９での大地電位勾
配の変化量VTは52ｍＶ、埋設配管１に対向した
一部で12ｍＶの変化量VHが測定され、埋設配置
１に被覆欠陥部１ａが生じている可能性が求めら
れた。 In the second actual measurement, the current-carrying surface area of buried pipe 1 buried at a depth of 0.75 m was 1 cm 2 (2r T =
Using the test piece 9 (1.13 cm), the inflow current I T into the test piece 9 when switch S is turned on is
2.56 mA, the amount of change V T in the ground potential gradient at test piece 9 was 52 mV, and the amount of change V H of 12 mV was measured in the part facing buried pipe 1, and a coating defect 1a occurred in buried arrangement 1. The possibility of
そこで、これらの計測結果を(5)式に代入する
と、欠陥部１ａに流れる電流IHは、
IH＝IT・VH／VT
＝2.56ｍＡ・12ｍＶ／52ｍＶ＝0.59ｍＡ
さらに、(7)式から欠陥部１ａの等価半径rHを求
めると、
rH＝rT・IH／IT
＝0.565cm・0.59ｍＡ／2.56ｍＡ＝0.13cm
となり、欠陥部１ａの直径2rHは0.26cmと算出さ
れた。 Therefore, by substituting these measurement results into equation (5), the current I H flowing through the defective part 1a is: I H = I T · V H /V T = 2.56 mA · 12 mV / 52 mV = 0.59 mA Furthermore, (7 ) Calculating the equivalent radius r H of the defective part 1a, r H = r T・I H /I T =0.565cm・0.59mA/2.56mA=0.13cm, and the diameter 2rH of the defective part 1a is 0.26cm. It was calculated that
掘削して埋設配管１を調査した結果、大地電位
勾配が変化した近傍で直径0.3cmの欠陥部１ａが
見つかり、算出値とかなり良く合致した。 As a result of excavating and investigating the buried pipe 1, a defective part 1a with a diameter of 0.3 cm was found in the vicinity where the ground potential gradient had changed, which agreed fairly well with the calculated value.
このように、本発明方法は、地表面上から埋設
配管１の欠陥部１ａの有無、位置、大きさ、そし
てその程度を知ることが出来るので、これを基に
して埋設配管１の寿命を掘削を行うことなく知る
ことが出来る。 In this way, the method of the present invention makes it possible to know the existence, position, size, and extent of the defective part 1a of the buried pipe 1 from above the ground surface, so based on this, the lifespan of the buried pipe 1 can be estimated by excavation. You can know without doing it.
それゆえ、埋設配管１の管入取替、管体修理等
が無駄なく、効率的に施工することが出来る。 Therefore, replacement of the buried pipe 1, repair of the pipe body, etc. can be carried out efficiently and without waste.
以上の説明から明らかなように、本発明による
塗覆装埋設管の被覆欠陥測定方法は、掘削作業を
要することなく、地表上から埋設配管の欠陥部の
有無、位置、大きさ、そしてその程度を知ること
が出来るので、埋設配管の維持、管理上極めて有
用であり、また掘削作業を必要としないので、埋
設配管の管入取替、管体修理等を要する費用を大
幅に低減することが出来、さらに埋設配管の寿命
を正確に予測することが出来るので、埋設配管の
長期にわたる管理を良好に行うことが出来る等多
くの優れた効果を有するものである。 As is clear from the above description, the method for measuring coating defects in coated buried pipes according to the present invention can detect the presence, location, size, and extent of defects in buried pipes from the ground surface without requiring excavation work. It is extremely useful for the maintenance and management of underground piping, and since no excavation work is required, the cost of replacing underground piping, repairing pipe bodies, etc. Furthermore, since it is possible to accurately predict the life of buried piping, it has many excellent effects, such as being able to properly manage buried piping over a long period of time.
第１図は、埋設配管の欠陥部検出のための一般
的な手法をしめす概念図である。第２図は、第１
図に示した手法により測定さた地表面電位勾配線
図である。第３図は、本発明方法の手法を示す概
念図である。第４図は、本発明方法により測定さ
れる地表面電位勾配線図である。第５図は、本発
明方法を実施した大地電位勾配測定設備の一例を
示す電気構成例図である。第６図は、第５図に示
した構成により得られた大地電位勾配測定線図で
ある。
符号の説明、１；埋設配管、１ａ；欠陥部、
２；電源、３；電圧計、５；接地電極、６；照合
電極、８；電流計、９；テストピース。
FIG. 1 is a conceptual diagram showing a general method for detecting defects in buried piping. Figure 2 shows the first
It is a ground surface potential gradient diagram measured by the method shown in the figure. FIG. 3 is a conceptual diagram showing the method of the present invention. FIG. 4 is a ground surface potential gradient diagram measured by the method of the present invention. FIG. 5 is a diagram illustrating an example of the electrical configuration of an earth potential gradient measurement facility in which the method of the present invention is implemented. FIG. 6 is a ground potential gradient measurement diagram obtained by the configuration shown in FIG. Explanation of symbols, 1; Buried pipe, 1a; Defective part,
2; power supply, 3; voltmeter, 5; grounding electrode, 6; reference electrode, 8; ammeter, 9; test piece.
Claims (1)
地を通して通電している状態で、針電極法により
前記埋設管の被覆欠陥部を測定探知すると共に、
該欠陥部の形成する大地電位勾配と互いに作用し
合わない前記欠陥部近傍に、通電表面面積の既知
なテストピースを設置し、該テストピースを前記
埋設管に電気的に接続して該テストピースを疑似
欠陥部として前記欠陥部と同様の測定を行つて前
記した実存の欠陥部との測定値比較をすることに
よつて、実存する欠陥部の面積を検知する塗覆装
埋設管の被覆欠陥測定方法。 ２ 装覆装埋設管に、別に設置した接地極から大
地を通して通電している状態で、針電極法により
前記埋設管の被覆欠陥部を測定探知すると共に、
該欠陥部の形成する大地電位勾配と互いに作用し
合わない前記欠陥部近傍に、通電表面面積の既知
なテストピースを設置し、該テストピースを前記
埋設管に電気的に接続して該テストピースを疑似
欠陥部として前記欠陥部と同様の測定を行つて前
記した実存の欠陥部との測定値比較をすることに
よつて、実存する欠陥部の面積を検知し、さらに
前記テストピースに電流計を接続すると共に前記
接地極からの通電を停止した状態で、前記テスト
ピースからの腐食電流を前記電流計により計測し
て前記欠陥部に流れる腐食電流を求める塗覆装埋
設管の被覆欠陥測定方法。[Claims] 1. Measuring and detecting coating defective parts of the coated buried pipe using a needle electrode method while applying electricity through the earth from a separately installed ground electrode,
A test piece with a known current-carrying surface area is installed near the defective part that does not interact with the ground potential gradient formed by the defective part, and the test piece is electrically connected to the buried pipe. The area of the existing defect is detected by performing the same measurements as the defect with the defect as a pseudo defect and comparing the measured values with the existing defect. Measuring method. 2. Measure and detect defects in the coating of the buried pipe using the needle electrode method while energizing the covered buried pipe through the ground from a separately installed ground electrode;
A test piece with a known current-carrying surface area is installed near the defective part that does not interact with the ground potential gradient formed by the defective part, and the test piece is electrically connected to the buried pipe. The area of the existing defect is detected by performing the same measurements as the defect with the pseudo defect and comparing the measured values with the existing defect. A method for measuring a coating defect in a coated buried pipe in which the corrosion current flowing from the test piece is measured by the ammeter with the test piece connected and the power supply from the ground electrode stopped, and the corrosion current flowing to the defective part is determined. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22024283A JPS60111949A (en) | 1983-11-22 | 1983-11-22 | Method for detecting coating defect of coated embedded pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22024283A JPS60111949A (en) | 1983-11-22 | 1983-11-22 | Method for detecting coating defect of coated embedded pipe |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60111949A JPS60111949A (en) | 1985-06-18 |
| JPH0334822B2 true JPH0334822B2 (en) | 1991-05-24 |
Family
ID=16748114
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22024283A Granted JPS60111949A (en) | 1983-11-22 | 1983-11-22 | Method for detecting coating defect of coated embedded pipe |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60111949A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63120246A (en) * | 1986-11-07 | 1988-05-24 | Toda Constr Co Ltd | Method for inspecting anticorrosion coating state of ground embedded piping |
| AT390969B (en) * | 1988-07-04 | 1990-07-25 | Flaga Handel | METHOD FOR DETERMINING THE CORROSION CONDITION OF A METAL OBJECT Buried In The Soil |
| CN102954754A (en) * | 2011-08-19 | 2013-03-06 | 丹阳奥恩能源科技发展有限公司 | Detection method for equivalent diameter of anticorrosive coating damaged surface of buried steel pipeline |
| DK2748576T3 (en) * | 2012-02-16 | 2019-03-11 | Electro Scan Inc | System and method for collecting, analyzing and archiving pipe defect data |
| CN110231111B (en) * | 2019-06-21 | 2020-02-28 | 西南石油大学 | Non-contact type stress real-time monitoring method for buried pipeline |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53134486A (en) * | 1977-04-28 | 1978-11-24 | Sumikin Kokan Koji Kk | Inspection method and apparatus for flawed parts of coated film on underground coated steel pipes |
-
1983
- 1983-11-22 JP JP22024283A patent/JPS60111949A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53134486A (en) * | 1977-04-28 | 1978-11-24 | Sumikin Kokan Koji Kk | Inspection method and apparatus for flawed parts of coated film on underground coated steel pipes |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60111949A (en) | 1985-06-18 |
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