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Inspection Procedures
Nov 11, 2018

Cutting inspection

Material surface quality

      The surface of the steel plate within the scope of the macro inspection material shall be visually inspected, and there shall be no defects such as delamination, cracks, crusting, pressing into the scale, and inclusions.

2. Measure the underline with a steel tape measure according to the drawings and process documentation.

3. Material grades and specifications must conform to the drawings.

4. Cutting surface

       The surface shall be inspected by visual inspection for macroscopic inspection. There shall be no delamination and the slag shall be cleaned.

5. Groove shape and angle

       Use the weld to detect the ruler or sample, check and measure according to the sample, and check the surface quality of the groove according to the requirements of the corresponding processing method.

6. Cutting size

a. According to the pattern or process, measure the dimensional deviation by ±10mm with a steel tape measure as required.

b. When using the sample line, the validity and correctness of the sample should be checked. If necessary, the sample mark should be in accordance with the process specifications.

c. When positioning and unloading, check the positioning standard and the first piece inspection after cutting.

2. Bending test

1. Bending forming inspection, according to drawings and process requirements

  a, use the template to detect the curved shape

b. Check the length deviation after bending is not more than ±5° dimensional change

2. Use a vernier caliper to bend and shape the length dimension with a ferrule

3. Visual inspection of the surface quality of the bend, bending must not be pulled

4. Bending deformation should meet the requirements of drawings and process documents

5. The shrinkage of the steel pipe should meet the requirements of the drawings and measure the size with a vernier caliper.

6. Visual inspection of the appearance quality, should comply with the drawings and process requirements.

3. Welding inspection

1. The quality of the weld surface

     Visual inspection of the weld and heat affected zone by macro inspection. If necessary, observe with a 5-10 magnification magnifying glass. No cracks, pores, craters, slag inclusions, slag and spatter are allowed on the weld surface.

2. Weld appearance

     Visual inspection of all welds, butt weld joint area should be smooth transition, no abrupt change; corner joint welds are not allowed to have obvious excessive convexity, asymmetry and collapse, joints should be smoothly transitioned to the base metal geometry .

3. Butt weld

3.1 Weld height

      a. Macroscopic inspection one by one, the weld bead shall not be lower than the base metal;

      b. Use the weld seam to measure the maximum height of the weld;

      c. The butt weld height is judged according to its depth. The single-sided welding is the thickness of the base metal. The two sides of the double-sided welding are calculated separately and should meet the requirements of Table 13-1.

Table 13-1

                                                                 Weld height e1, e2 (mm)
Steel with standard lower tensile strength δb>540MPa and Cr-Mo low alloy steel                                Other steel
Single bevelDouble-sided grooveSingle bevelDouble-sided groove









0 to 10%


And ≤3


0 to 10%


And ≤3

0 to 10%


And ≤3

0 to 15%


And ≤3


0 to 15%


And ≤4

0 to 15%


And ≤4

3.2 Weld width

       a. Determine the standard width according to the welding process weld pattern;

       b. Macroscopic inspection, taking the widest and narrowest part of the measurement, subdivided by the measured data, and in accordance with the provisions of Table 13-2.

Table 13-2

                                 Weld width (mm)
Not more than the width of the outer edge of the groove +8Same strip width differenceSame type of weld width and narrow difference

4. Weld seam undercut inspection

4.1 Macroscopic inspection, the undercut part is drawn, the length is measured with a steel tape measure, etc.; the undercut depth is measured by the weld bead detection ruler needle scale.

4.2 The undercut depth of other pressure vessels shall not exceed 0.5mm, the continuous length shall not exceed 100mm, and the total length of the undercuts on both sides of the weld shall not exceed 10% of the length of the weld.

5. Process discipline inspection

5.1 On-site inspection, according to the product requirements, selectively check whether the welding personnel have a valid certificate consistent with the welding type;

5.2 The welding process shall comply with the effective process of the product. The welding materials, welding parameters and preheating temperature shall comply with the welding process card regulations.

6 weld repair

6.1 The number of weld repairs in the same part is generally not more than two times. If the weld is still unqualified after two repairs, the rework should be approved by the chief technical officer.

6.2 Weld repair must be handled and held with the appropriate approval procedures and repair process, and repaired by the welder with the corresponding qualified items.

6.3 Other personnel shall not substitute when the designated personnel perform the repair.

6.4 Rework soldering inspection shall be carried out in accordance with the corresponding content requirements of the weld form.

7. Weld repair inspection

7.1 Can be combined with weld appearance inspection requirements.

7.2 Use the ultrasonic thickness gauge to detect the repaired parts. If the ultrasonic thickness gauge can't detect, the thickness of the adjacent base metal can be measured. Then, the adjacent base metal and the grinding point are measured by the weld bead, and the grinding is calculated. The minimum thickness.

7.3 The weld dressing shall be naturally transitioned with a minimum slope of not less than 3:1; the thickness of the dressing shall not be less than the difference between the nominal thickness δn and the negative deviation of the steel plate C1; the weld of the composite steel plate (referred to as the composite layer) shall be Not more than 30% of the composite layer and not more than 1 mm.

8. Pipe and tube plate welding

8.1 Check the inner end of the pipe end one by one with the plug gauge of the corresponding port diameter of the heat transfer tube; the spatter and the weld bead protruding from the inner wall of the pipe should be removed. The pipe diameter requirements are in accordance with Table 13-3:

Heat exchanger tube outer diameter d≤2525<d≤40>40
Pipe port diameter a≥0.75d≥0.8d≥0.85d

8.2 joints for welding and expansion shall also be able to be inserted into the tube freely;

8.3 In addition to inspection in accordance with this section, it shall be inspected in accordance with other relevant provisions of this chapter.

4 assembly inspection

1. The amount of misalignment of the welded joint

a. Thoroughly inspect the welded joint, and measure the largest part of the wrong side with the angular wrong edge detection ruler.

b. Measure the difference in the value of the welded joint.

2. Welding joint arrangement; according to the requirements of drawings and process documents, the inner edge of the welding head with the smallest adjacent distance is measured with a ferrule.

3. Measure the dimensions and nozzle orientation according to the parts drawing and manufacturing process and meet the requirements.

Second, the welding joint arrangement

1. Use a ferrule to measure the inner edge of the welded joint with the smallest adjacent distance.

2. Distance measurement of lap joints, fillet welds and any adjacent joints shall be tested according to the values specified in the drawings and process documents.

Third, take over the nozzle mouth position inspection

1. Check the dimensions of each part according to the drawings and process documents, check the connection direction of each nozzle, and whether the size requirements of each part meet the drawings and process requirements.

2. Check whether the connection between each nozzle and the elbow connection at the joint is smooth.

Fourth, pipeline inspection

    According to the drawings and process documents, the distribution position of each pipeline should meet the requirements specified in the drawings.

V. 1. The test pressure is 30 MPa.

2. One-time pressure test should reach 24 hours.

3. Test the pressure twice and test the equipment with a test press.

Sixth, shape, spray paint packaging inspection

    Acceptance according to the management system "Inspection Standard for Finished Equipment".

5. Finished equipment inspection standards

1. Finished product inspection is carried out according to Q/DQ GKA 0001-2016-2016 oilfield superconducting multi-function well washing equipment enterprise standard

Second, the factory inspection

Each wax cleaning device should be inspected before leaving the factory. The factory inspection items are as follows:

a) commissioning test;

The product equipment needs to open all the valves on the inlet and outlet pipelines under no-load condition, and circulate with clear water for not less than 30 minutes.

b) performance test;

According to the light, medium and heavy load of the design grade, the speed is gradually increased, the furnace is ignited, and the pressure rises slowly from zero to the rated working condition. During the chemical wax cleaning equipment test, the pressure is gradually increased to the rated working pressure, and the voltage regulation time of each gear is not less than 30 minutes. Check and record the pressure, displacement, temperature rise and leakage. Record no less than 3 times, the test time is not Less than 3h. 

c) safety valve test;

The safety valve is normally applied with a pressure of 35mpa, the safety valve opening pressure is 1.05~1.25 times the rated working pressure, and the test is not less than 3 times.

d) Temperature fuse test.

The test temperature of the temperature fuse is 1.05 to 1.25 times the rated working temperature, and the test is not less than 3 times.

e) shape

The deviation is not higher than length × width × height (± 20mm)

f) paint surface

The paint should be even and bright, and there must be no paint leakage, sag, wrinkles or peeling.













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