CN101403474A - Security assessment method for pressure pipe containing incomplete fusion defect - Google Patents

Abstract

The invention discloses a safety assessment method for a pressure conduit containing defects of incomplete fusion. The method comprises the following steps of: obtaining the position, shape and size of each incomplete fusion defect of a conduit to be detected and limiting the Cmax allowed by different Theta; then concretely detecting each incomplete fusion defect and judging whether the pressure conduit is safe according to corresponding calculation formulas; keeping the control valve of the pressure conduit in an opening state with the judgment of safety; otherwise, closing the valve. The use of the assessment method can prevent an abrupt failure accident caused by the pressure conduit from happening so as to ensure the safe use of the pressure conduit.

Description

The pressure piping man-rate method that contains incomplete penetration defect

Technical field

The present invention relates to a kind of safety monitoring method of pressure piping, particularly pressure piping man-rate method.

Background technique

Pressure piping is a kind of extraordinary bearing device with explosion risk, is undertaking the conveying task of high temperature, high pressure, inflammable, explosive, hypertoxic, deep-etching or radioactivity material, occupies critical role in the development of the national economy.The integrity of pressure piping is directly connected to the safety of production, in case take place to leak or blast, often causes catastrophic failure.Ubiquity a large amount of defectives in pressure piping manufacturing and using process, wherein is at most especially with the incomplete penetration defect, brings serious threat for the safe handling of pressure piping.Therefore, Security how to review the pressure piping that contains incomplete penetration defect is a focus academic both at home and abroad at present and that engineering circle is studied.

Pressure piping generally adopts toughness material preferably, and its failure mode is the ductile failure of plastic limit load control.But the structure of pressure piping and load have its outstanding feature: the diameter and the wall thickness of pressure piping are less, and weld seam is generally hoop butt weld, welding by one side, and very easily there is incomplete penetration defect in internal surface, and defective generally also is a hoop.The load more complicated of pressure piping, except inner pressuring load, also have piping expansion, piping deadweight, force to install etc. causes the whole bending load that pipeline bears, in general, pipeline is not main load often by the membrane stress that interior pressure causes, the load that causes pipeline to lose efficacy mainly is bending load.Because pressure piping has These characteristics, makes its man-rate technology also be different from pressurized container.At present, China does not also have to contain at this class specially the man-rate method of the pressure piping of incomplete penetration defect.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of pressure piping man-rate method that contains incomplete penetration defect, uses this assessment method can prevent the generation of the sudden malicious event of pressure piping, thereby guarantees the safe handling of pressure piping.

In order to solve the problems of the technologies described above, the invention provides a kind of pressure piping man-rate method that contains incomplete penetration defect, comprise position, shape and the size of obtaining each incomplete penetration defect in the pipe under test; Also comprise:

At first, limit the maximum limit Cmax of the incomplete penetration defect relative depth c that is allowed under the different relative hoop length of the incomplete penetration defect θ:

When θ≤0.25, Cmax=0.5;

0.25＜θ≤0.75 at that time, Cmax=0.37;

When 0.75＜θ≤1, Cmax=0.3;

Then, each incomplete penetration defect is carried out the detection of following steps:

1), judge whether to be suitable for this method:

When satisfying following 2 conditions simultaneously, enter step 2); Otherwise detection of end;

1. pipeline material is an Austenitic Stainless Steel;

2. 1.1≤K≤1.4, described K=R are satisfied than K in the pipeline footpath ₀/ R _iR ₀Be the residing pipe under test external diameter of incomplete penetration defect, R _iBe the residing pipe under test internal diameter of incomplete penetration defect;

2), obtain the regularity parameter of incomplete penetration defect:

Obtain the regularity hoop length L of incomplete penetration defect and the regularity depth H of incomplete penetration defect;

$L=\frac{1}{2}l,$ Described l is the hoop length of the strong point of reality of incomplete penetration defect; H=h, described h are the actual innermost degree of depth of incomplete penetration defect;

3), preliminary judgement:

When meeting the following conditions (promptly satisfying following 2 conditions simultaneously), enter step 4); Otherwise enter step 12);

The T of H＜70% and T-H 〉=1.2mm; Described T represents wall thickness, T=R ₀-R _i

4), the nondimensionalization of incomplete penetration defect is handled:

The relative hoop length of incomplete penetration defect θ=L/ (π R _i); Incomplete penetration defect relative depth: c=H/T;

5), press P in the plastic limit that acquisition zero defect pipeline is depressed in pure _L0With the plastic limit bending moment M under the simple bending square _L0 $P_{L0}=\frac{2}{\sqrt{3}}{\mathrm{\σ}}_f\ln K,$ $M_{L0}=4{\mathrm{\σ}}_f\frac{(R_0^3-R_i^3)}{3};$

Described ${\mathrm{\σ}}_f=\frac{1}{2}({\mathrm{\σ}}_s+{\mathrm{\σ}}_b),$ σ _sBe pipe under test YIELD STRENGTH, σ _bTensile strength for the pipe under test material;

6), whether pipe under test being avoided evaluation judges:

When satisfying following 3 conditions simultaneously, enter step 11); Otherwise enter step 7);

1. the physical dimension of whole pipe under test adheres to specification;

2. P/P _L0≤ 0.5; Described P is the actual pressure that bears of pipe under test;

3. lack of penetration relative depth c≤C _Max

7), obtain the plastic limit load P that pipe under test is depressed in pure ₁With the plastic limit load M under the simple bending square ₁

P ₁=p ₁* P _L0, in the formula: ${\mathrm{<figure-callout\; id="1"\; label="p"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">p</figure-callout>}}_1=0.9571-3.0346{\mathrm{<figure-callout\; id="1"\; label="G"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">G</figure-callout>}}_1+5.5967{{\mathrm{<figure-callout\; id="1"\; label="G"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">G</figure-callout>}}_1}^2,$ G ₁＝c ^3.9012θ ^0.6755；

M ₁=m ₁* M _L0, in the formula: ${\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">m</figure-callout>}}_1=0.9607-1.5259G_2+0.7626{G_2}^2,$ G ₂＝c ^0.8332θ ^0.1722；

8), comprehensively judge according to actual interior pressure and the moment M of bearing in incomplete penetration defect place in the pipe under test:

When lack of penetration relative depth c≤0.4, enter step 9); Otherwise carry out step 10); The actual interior pressure=P that bears in incomplete penetration defect place in the described pipe under test;

9), when satisfying ${\left(\frac{P}{P_1}\right)}^{15}+{\left(\frac{M}{M_1}\right)}^{15}\&le;0.56$ The time, enter step 11), otherwise carry out step 12);

10), when satisfying $\frac{\mathrm{<figure-callout\; id="1"\; label="P\; P"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">P</figure-callout>}}{P_{}}+\frac{\mathrm{<figure-callout\; id="1"\; label="M\; M"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">M</figure-callout>}}{M_{}}\&le;0.57$ The time, enter step 11), otherwise carry out step 12);

11), the keep-up pressure valve of pipeline is an open mode;

12), the valve of closing pressure pipeline.

As the improvement that contains incomplete penetration defect pressure piping man-rate method of the present invention: position, shape and the size of obtaining each incomplete penetration defect in the pipe under test by nondestructive detecting method.

To man-rate method of the present invention, do the description below explanation:

T-H in the step 3) represents the bottom wall thickness of incomplete penetration defect, so T-H 〉=1.2mm means: the bottom minimum wall thickness (MINI W.) of incomplete penetration defect is necessary 〉=and 1.2mm.

In the step 6): the physical dimension of the whole pipe under test of condition in 1. adheres to specification, and the physical dimension that refers to the pipe under test actual measurement is consistent with the physical dimension on the design drawing.The pipe under test actual pressure P of bearing of condition in 2., its data can obtain by the pressure gauge that is installed on the pipeline; In whole pipe under test, the size of P equates, so the actual interior pressure=P that bears in incomplete penetration defect place in the pipe under test.Condition 3. in, at first according to the relative hoop length of the incomplete penetration defect θ of step 4) gained, thus selected corresponding C _MaxAnd then allow lack of penetration relative depth c C therewith _MaxCompare.

The actual moment M of bearing in incomplete penetration defect place in the step 8) can obtain by conventional FEM (finite element) calculation method or measurement method.

Because the particularity of pressure piping, whole pressure piping all adopts commaterial to make, and pressure piping all satisfies following 2 conditions simultaneously generally speaking: 1. pipeline material is an Austenitic Stainless Steel; 2. 1.1≤K≤1.4, described K=R are satisfied than K in the pipeline footpath ₀/ R _iR ₀Be pipe under test external diameter, R _iBe the pipe under test internal diameter.Therefore, all suitable method of the present invention of Jue Daduoshuo pressure piping is carried out man-rate.

Because man-rate method of the present invention can carry out corresponding judgment and analysis by computer, therefore the result when step 1) is inapplicable this method, thereby when needing detection of end, can be provided the corresponding information of " detection of end " by computer.

The pressure piping man-rate method that contains incomplete penetration defect of the present invention is a kind of with plastic limit load P ₁And M ₁Be the man-rate new technology of control signal, that this technology has is safe and reliable, intuitive is strong, calculation accuracy is high, with characteristics such as actual degree of agreement is good.The present invention controls in real time pressure piping by computer and (by computer pressure piping is detected incessantly, immediately make and close or keep operational orders such as use, come the respective valves of pilot pressure pipeline again by instruction), thus being perfectly safe of pipeline guaranteed.Therefore the present invention is for the safe operation that ensures industrial pressure piping, trouble-saving generation, bring into play at the economic efficacy with industrial pressure piping and have great importance to greatest extent.

Description of drawings

Below in conjunction with accompanying drawing the specific embodiment of the present invention is described in further detail.

Fig. 1 is the schematic representation that the incomplete penetration defect regularity characterizes; Among the figure 1 represents incomplete penetration defect, and B represents the width of incomplete penetration defect 1, and B is generally about 2mm;

Fig. 2 is the cross-sectional schematic of Fig. 1 at the incomplete penetration defect place.

Embodiment

A kind of pressure piping man-rate method that contains incomplete penetration defect comprises following content:

The first, limit the maximum limit Cmax of the incomplete penetration defect relative depth c that the different relative hoop length of incomplete penetration defect θ allowed down:

When θ≤0.25, Cmax=0.5;

0.25＜θ≤0.75 at that time, Cmax=0.37;

When 0.75＜θ≤1, Cmax=0.3;

Deposit the pairing Cmax of above-mentioned θ in Computer Database, stand-by.

The second, qualitative by nondestructive detecting method (for example ray or ultrasound examination), quantitatively obtain position, shape and the size of incomplete penetration defect in the whole testing pressure pipeline, with this type of initial imperfection information input computer.Simultaneously, the initial information (as structure, material and force-bearing situation etc.) of pressure piping is also imported computer.

The 3rd, with the design of structural size parameter of pressure piping input computer, the physical dimension of the pressure piping of actual measurement gained is also imported computer.

The 4th, when the pressure piping real work, with the actual moment M input computer that bears of the actual pressure P of bearing of pipe under test and each incomplete penetration defect place that records in real time; The detection of carrying out following steps (, therefore can realize each incomplete penetration defect is detected in real time) that relies on computer that each incomplete penetration defect is taken turns owing to be to utilize computer very apace each incomplete penetration defect to be taken turns to detect:

1), judge whether to be suitable for this method:

When satisfying following 2 conditions simultaneously, enter step 2); Otherwise detection of end;

1. pipeline material is an Austenitic Stainless Steel;

2. 1.1≤K≤1.4, described K=R are satisfied than K in the pipeline footpath ₀/ R _iR ₀Be the residing pipe under test external diameter of incomplete penetration defect, R _iBe the residing pipe under test internal diameter of incomplete penetration defect.

2), incomplete penetration defect carried out regularity handle, thereby obtain the regularity parameter of incomplete penetration defect, promptly obtain the regularity hoop length L of incomplete penetration defect and the regularity depth H of incomplete penetration defect:

$L=\frac{1}{2}l,$ L is the extreme length on the hoop of the incomplete penetration defect that obtains of non-destructive inspection; H=h, h are the maximum depth that incomplete penetration defect that non-destructive inspection obtains directly makes progress.

3), preliminary judgement:

When meeting the following conditions, enter step 4); Otherwise enter step 12);

The T of H＜70% and T-H 〉=1.2mm; T represents wall thickness, T=R ₀-R _i

4), the incomplete penetration defect after the regularity carried out nondimensionalization handle, obtain incomplete penetration defect relative hoop length θ and incomplete penetration defect relative depth c,

θ＝L/(πR _i)；c＝H/T。

5), adopt following formula to calculate in the plastic limit that the zero defect pipeline depresses in pure and press P _L0With the plastic limit bending moment M under the simple bending square _L0 $P_{L0}=\frac{2}{\sqrt{3}}{\mathrm{\&sigma;}}_f\ln K,$ $M_{L0}=4{\mathrm{\&sigma;}}_f\frac{(R_o^3-R_i^3)}{3};$

Described ${\mathrm{\&sigma;}}_f=\frac{1}{2}({\mathrm{\&sigma;}}_s+{\mathrm{\&sigma;}}_b),$ σ _sBe pipe under test YIELD STRENGTH, σ _bTensile strength for the pipe under test material;

6), whether pipe under test being avoided evaluation judges:

When satisfying following 3 conditions simultaneously, enter step 11); Otherwise enter step 7);

1. the physical dimension of whole pipe under test adheres to specification;

Be about to the interior pressure piping design of structural size parameter of computer and the data of actual measurement gained and compare, thereby determine whether to adhere to specification;

2. P/P _L0≤ 0.5; Described P is the actual pressure that bears of pipe under test;

3. lack of penetration relative depth c≤C _MaxIn this step: at first according to the relative hoop length of the incomplete penetration defect θ of step 4) gained, thus selected corresponding C _MaxAnd then allow lack of penetration relative depth c C therewith _MaxCompare.

7), adopt following formula to calculate the plastic limit load P that pipe under test is depressed in pure ₁With the plastic limit load M under the simple bending square ₁

P ₁=p ₁* P _L0, in the formula: ${\mathrm{<figure-callout\; id="1"\; label="p"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">p</figure-callout>}}_1=0.9571-3.0346{\mathrm{<figure-callout\; id="1"\; label="G"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">G</figure-callout>}}_1+5.5967{{\mathrm{<figure-callout\; id="1"\; label="G"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">G</figure-callout>}}_1}^2,$ G ₁＝c ^3.9012θ ^0.6755；

M ₁=m ₁* M _L0, in the formula: ${\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">m</figure-callout>}}_1=0.9607-1.5259G_2+0.7626{G_2}^2,$ G ₂＝c ^0.8332θ ^0.1722；

8), comprehensively judge: when lack of penetration relative depth c≤0.4, enter step 9) according to actual interior pressure of bearing in incomplete penetration defect place in the pipe under test (promptly=the actual pressure P of bearing of pipe under test) and moment M; Otherwise carry out step 10);

9), when satisfying ${\left(\frac{P}{P_1}\right)}^{15}+{\left(\frac{M}{M_1}\right)}^{15}\&le;0.56$ The time, enter step 11), otherwise carry out step 12);

10), when satisfying $\frac{\mathrm{<figure-callout\; id="1"\; label="P\; P"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">P</figure-callout>}}{P_{}}+\frac{\mathrm{<figure-callout\; id="1"\; label="M\; M"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">M</figure-callout>}}{M_{}}\&le;0.57$ The time, enter step 11), otherwise carry out step 12);

11), the valve of computer command pilot pressure pipe switch remains on open mode;

12), the valve closing of computer command pilot pressure pipe switch.

Embodiment 1, a pressure piping that contains incomplete penetration defect is arranged.Its design parameter is: material is 0Cr18Ni9 (σ _s=205MPa, σ _b=520MPa), specification is Φ 89 * 4 (R ₀=44.5mm, R _i=40.5mm, wall thickness T=4mm), through non-destructive inspection, have only an incomplete penetration defect, it is of a size of: actual rings is to extreme length l=128mm, actual bosom degree of depth h=1.5mm, width B=2mm.During real work, pressure P=6.4MPa that pipeline bears.The maximum limit Cmax of the incomplete penetration defect relative depth c that the relative hoop length of different incomplete penetration defects θ is allowed down is with embodiment 1;

Evaluation process to this incomplete penetration defect is as follows:

1), judge whether to be suitable for this method:

1. whether pipeline material is Austenitic Stainless Steel: be;

2. pipeline is directly than K=R ₀/ R _i=44.5/40.5=1.1 satisfies 1.1≤K≤1.4;

Conclusion: satisfy above 2 conditions simultaneously, therefore enter step 2);

2), obtain the regularity parameter of incomplete penetration defect:

The regularity hoop length L of incomplete penetration defect: $L=\frac{1}{2}l=64\mathrm{mm},$

The regularity depth H of incomplete penetration defect: H=h=1.5mm.

3), preliminary judgement:

H/T＝1.5/4＝0.375＜0.7，T-H＝4-1.5＝2.5mm≥1.2mm；

Conclusion: satisfy above condition, therefore enter step 4);

4), the nondimensionalization of incomplete penetration defect is handled:

Relative hoop length θ=L/ (π R _i)=64/ (3.14 * 40.5)=0.5

Relative depth: c=H/T=1.5/4=0.375

5), press P in the plastic limit that acquisition zero defect pipeline is depressed in pure _L0With the plastic limit bending moment M under the simple bending square _L0

$P_{L0}=\frac{2}{\sqrt{3}}{\mathrm{\&sigma;}}_f\ln K=\frac{2}{\sqrt{3}}\&times;\frac{1}{2}({\mathrm{\&sigma;}}_s+{\mathrm{\&sigma;}}_b)\ln \frac{R_0}{R_i}=\frac{2}{\sqrt{3}}\&times;\frac{1}{2}(205+520)\ln \frac{44.5}{40.5}=39.4\mathrm{MPa}$

$M_{L0}=4{\mathrm{\&sigma;}}_f\frac{(R_o^3-R_i^3)}{3}=4\&times;\frac{1}{2}(205+520)\frac{{44.5}^3-{40.5}^3}{3}=31.4\mathrm{KN}\&CenterDot;m;$

6), whether pipe under test being avoided evaluation judges:

1. because of actual measurement pipeline configuration size is consistent with design size, thereby the identification pipeline configuration meets and manufactures and designs requirement;

②P/P _L0＝6.4/39.4＝0.16≤0.5；

3. according to relative hoop length θ=0.5, looking into following table can get: C _Max=0.37

Lack of penetration relative hoop length θ	θ≤0.25	0.25＜θ≤0.75	0.75＜θ≤1
				The lack of penetration relative depth C that allows max	0.5	0.37	0.3

Because: c=0.375＞C _Max, do not satisfy condition.

Therefore enter step 7).

7), obtain the plastic limit load P that pipe under test is depressed in pure ₁With the plastic limit load M under the simple bending square ₁

P ₁＝p ₁×P _L0＝0.916×39.4＝36.1MPa

In the formula: ${\mathrm{<figure-callout\; id="1"\; label="p"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">p</figure-callout>}}_1=0.9571-3.0346{\mathrm{<figure-callout\; id="1"\; label="G"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">G</figure-callout>}}_1+5.5967{{\mathrm{<figure-callout\; id="1"\; label="G"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">G</figure-callout>}}_1}^2=0.916,$ G ₁＝c ^3.9012θ ^0.6755＝0.014；

M ₁＝m ₁×M _L0＝0.48×31.4＝15.1KN·m

In the formula: ${\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="A20081016202600121.png"\; state="\{\{state\}\}">m</figure-callout>}}_1=0.9607-1.5259G_2+0.7626{G_2}^2=0.48$ G ₂＝c ^0.8332θ ^0.1722＝0.392；

8), comprehensively judge according to actual interior pressure P and the moment M of bearing in incomplete penetration defect place in the pipe under test

The actual interior pressure P=6.4MPa that bears,

Moment M obtains according to actual measurement (also can pass through FEM (finite element) calculation): M=9.5KNm

Because: lack of penetration relative depth c≤0.4, so enter step 9) evaluation;

9)、 ${\left(\frac{P}{P_1}\right)}^{1.5}+{\left(\frac{M}{M_1}\right)}^{1.5}={\left(\frac{6.4}{36.1}\right)}^{1.5}+{\left(\frac{9.5}{15.1}\right)}^{1.5}=0.574>0.56,$ Thereby pressure piping is unsafe;

10), the valve of closing pressure pipeline.

At this moment, if open valve by force, contain the incomplete penetration defect place leakage phenomenon takes place.

At last, it is also to be noted that what more than enumerate only is several specific embodiments of the present invention.Obviously, the invention is not restricted to above embodiment, many distortion can also be arranged.All distortion that those of ordinary skill in the art can directly derive or associate from content disclosed by the invention all should be thought protection scope of the present invention.

Claims (2)

1, a kind of pressure piping man-rate method that contains incomplete penetration defect comprises position, shape and the size of obtaining each incomplete penetration defect in the pipe under test; It is characterized in that also comprising:

At first, limit the maximum limit Cmax of the incomplete penetration defect relative depth c that is allowed under the different relative hoop length of the incomplete penetration defect θ:

When θ≤0.25, Cmax=0.5;

0.25＜θ≤0.75 at that time, Cmax=0.37;

When 0.75＜θ≤1, Cmax=0.3;

Then, each incomplete penetration defect is carried out the detection of following steps:

1), judge whether to be suitable for this method:

When satisfying following 2 conditions simultaneously, enter step 2); Otherwise detection of end;

1. pipeline material is an Austenitic Stainless Steel;

2. 1.1≤K≤1.4, described K=R are satisfied than K in the pipeline footpath ₀/ R _iR ₀Be the residing pipe under test external diameter of incomplete penetration defect, R _iBe the residing pipe under test internal diameter of incomplete penetration defect;

2), obtain the regularity parameter of incomplete penetration defect:

Obtain the regularity hoop length L of incomplete penetration defect and the regularity depth H of incomplete penetration defect;

$L=\frac{1}{2}l,$ Described l is the hoop length of the strong point of reality of incomplete penetration defect; H=h, described h are the actual innermost degree of depth of incomplete penetration defect;

3), preliminary judgement:

When meeting the following conditions, enter step 4); Otherwise enter step 12);

The T of H＜70% and T-H 〉=1.2mm; Described T represents wall thickness, T=R ₀-R _i

4), the nondimensionalization of incomplete penetration defect is handled:

The relative hoop length of incomplete penetration defect θ=L/ (π R _i); Incomplete penetration defect relative depth: c=H/T;

5), press PL0 and the plastic limit bending moment M under the simple bending square in the plastic limit that acquisition zero defect pipeline is depressed in pure _L0

$P_{L0}=\frac{2}{\sqrt{3}}{\mathrm{\&sigma;}}_f\ln K,$ $M_{L0}=4{\mathrm{\&sigma;}}_f\frac{(R_o^3-R_i^3)}{3};$

Described ${\mathrm{\&sigma;}}_f=\frac{1}{2}({\mathrm{\&sigma;}}_s+{\mathrm{\&sigma;}}_b),$ σ _sBe pipe under test YIELD STRENGTH, σ _bTensile strength for the pipe under test material;

6), whether pipe under test being avoided evaluation judges:

When satisfying following 3 conditions simultaneously, enter step 11); Otherwise enter step 7);

1. the physical dimension of whole pipe under test adheres to specification;

2. P/P _L0≤ 0.5; Described P is the actual pressure that bears of pipe under test;

3. lack of penetration relative depth c≤C _Max

7), obtain the plastic limit load P that pipe under test is depressed in pure ₁With the plastic limit load M under the simple bending square ₁

P ₁=p ₁* P _L0, in the formula: p ₁=0.9571-3.0346G ₁+ 5.5967G ₁ ², G ₁=c ^3.9012θ ^0.6755

M ₁=m ₁* M _L0, in the formula: m ₁=0.9607-1.5259G ₂+ 0.7626G ₂ ², G ₂=c ^0.8332θ ^0.1722

8), comprehensively judge according to actual interior pressure and the moment M of bearing in incomplete penetration defect place in the pipe under test:

When lack of penetration relative depth c≤0.4, enter step 9); Otherwise carry out step 10); The actual interior pressure=P that bears in incomplete penetration defect place in the described pipe under test;

9), when satisfying ${\left(\frac{P}{P_1}\right)}^{15}+{\left(\frac{M}{M_1}\right)}^{15}\&le;0.56$ The time, enter step 11), otherwise carry out step 12);

10), when satisfying $\frac{P}{P_1}+\frac{M}{M_1}\&le;0.57$ The time, enter step 11), otherwise carry out step 12);

11), the keep-up pressure valve of pipeline is an open mode;

12), the valve of closing pressure pipeline.

2, the incomplete penetration defect pressure piping man-rate method that contains according to claim 1 is characterized in that: position, shape and the size of obtaining each incomplete penetration defect in the pipe under test by nondestructive detecting method.

Images