CN118817171A - Water tightness test equipment and test method for direct buried thermal insulation pipe joints - Google Patents

Abstract

The device comprises a water jacket, a sealing mechanism, a water inlet pipeline and a high-pressure water injection device; the water jacket is of a cylindrical structure, sleeved at the joint part of the heat preservation pipe, the length of the water jacket is longer than that of the sleeve of the heat preservation pipe joint, sealing mechanisms are assembled at two ends of the water jacket, annular spaces between two ends of the water jacket and the outer protective pipe of the heat preservation pipe are sealed through the sealing mechanisms, water filling ports and exhaust valves are arranged on the outer side wall of the water jacket, and the water filling ports and the exhaust valves are positioned at two sides of the axial edge of the sleeve of the heat preservation pipe joint; one end of the water inlet pipeline is connected with a water injection port on the water jacket, the other end of the water inlet pipeline is connected with a high-pressure water injection device, and a control valve is arranged on the water inlet pipeline. The invention realizes the water tightness test of the heat-preservation pipe joint, and achieves the purposes of ensuring the product quality and reducing the operation and maintenance cost of a pipe network.

Description

Water tightness test equipment and test method for direct buried thermal insulation pipe joints

Technical Field

The invention relates to the technical field of thermal insulation pipes, and in particular to a test device and a test method for performing water tightness test on joints of directly buried thermal insulation pipes.

Background Art

Prefabricated direct-buried insulated pipes have the characteristics of thermal insulation, flame retardancy, corrosion resistance and simple and quick construction. They have become indispensable fluid medium transportation facilities in the fields of construction, petroleum, chemical industry, municipal construction, etc. They are widely used in thermal insulation and cooling projects of central heating pipelines, central air-conditioning pipelines, chemical industry, medicine and other industrial pipelines, as well as oil and gas pipeline projects.

During the installation of prefabricated direct buried insulated pipes, two adjacent pipe sections are connected by joints, among which the casing joint is the main way to connect prefabricated direct buried insulated pipes. In this way, the casing joint uses a polyethylene casing with the same material and density as the outer protective pipe of the prefabricated insulated pipe. The polyethylene casing joint and the outer protective pipe of the main pipe are connected and sealed with a heat shrink tape. For the insulated pipes laid by direct burial, if there are sealing defects at the joints, the accumulated water in the stratum will penetrate into the insulation layer, corrode the outer wall of the working steel pipe, and have an adverse effect on the normal operation and maintenance of the pipe network. In order to avoid the above problems, according to the relevant technical standards for prefabricated direct buried pipes, it is necessary to conduct a water sealing performance test on the joints of the direct buried insulated pipes.

Summary of the invention

The present invention provides a water tightness test device and a test method for a direct-buried insulated pipe joint, which aims to test the water tightness of the insulated pipe joint by arranging a high-pressure water jacket at the joint of the insulated pipe, applying pressure to the joint of the insulated pipe through the high-pressure water jacket and maintaining a constant pressure state, so as to achieve the purpose of ensuring product quality and reducing the operation and maintenance costs of the pipe network.

In order to achieve the above object, the present invention adopts the following technical scheme:

A water tightness test device for a directly buried insulated pipe joint, wherein the workpiece to be tested is an insulated pipe with a complete joint in the middle part, and the insulated pipe is placed horizontally; the water tightness test device for a directly buried insulated pipe joint comprises a water jacket, a sealing mechanism, a water inlet pipeline and a high-pressure water injection device; the water jacket is a cylindrical structure, which is sleeved on the joint part of the insulated pipe, and the length of the water jacket is greater than the length of the sleeve of the insulated pipe joint, and sealing mechanisms are arranged at both ends of the water jacket, and the annular space between the two ends of the water jacket and the outer protective pipe of the insulated pipe is sealed by the sealing mechanism, and a water injection port and an exhaust valve are arranged on the outer side wall of the water jacket, and the water injection port and the exhaust valve are located on both sides of the axial edge of the sleeve of the insulated pipe joint; one end of the water inlet pipeline is connected to the water injection port on the water jacket, and the other end is connected to the high-pressure water injection device, and a control valve is arranged on the water inlet pipeline.

The above-mentioned direct-buried thermal insulation pipe joint water tightness test equipment is provided with a water pressure control component on the water inlet pipeline, and the water pressure control component includes a pressure regulating valve and a pressure gauge.

The above-mentioned direct-buried thermal insulation pipe joint water tightness test equipment, the high-pressure water injection device is a water tank installed at a set height, and the water outlet of the water tank is connected to the water inlet pipeline.

The above-mentioned direct-buried thermal insulation pipe joint water tightness test equipment, the high-pressure water injection device is a water pump arranged on the water inlet pipeline.

The above-mentioned direct-buried insulated pipe joint water tightness test equipment, the sealing mechanism includes an inflatable sealing ring, a sealing ring fixing seat and a bolt assembly; the sealing ring fixing seat is an annular support that matches the inner diameter of the water jacket, and has an L-shaped cross-sectional structure, and its side wall is assembled with the water jacket through a bolt assembly, and an inflatable sealing ring is embedded on the bottom surface of the sealing ring fixing seat; the bolt assemblies are evenly arranged in several groups along the circumference of the water jacket.

The above-mentioned direct-buried thermal insulation pipe joint water tightness test equipment, the water jacket is made of steel plate and is made by a rolling welding process.

The above-mentioned direct-buried thermal insulation pipe joint water tightness test equipment, the water jacket is also provided with a drain valve, and the drain valve is located at the bottom of the water jacket.

A method for testing the water tightness of a direct-buried thermal insulation pipe joint is provided. The water tightness test of a tested workpiece is completed by using the above-mentioned direct-buried thermal insulation pipe joint water tightness test equipment. The operation steps are as follows:

a. Put the water jacket on the outside of the workpiece to be tested, and then place the workpiece to be tested horizontally on the workpiece support;

b. Adjust the position of the water jacket so that it completely covers the joint sleeve on the tested workpiece, and then fill the inflatable sealing ring with high-pressure gas. The inflatable sealing ring expands to seal the annular space between the two ends of the water jacket and the outer protective tube of the insulation tube;

c. Connect the water inlet on the water jacket to the water inlet pipe;

d. Open the water jacket exhaust valve and the control valve of the water inlet pipeline, inject high-pressure water into the water jacket, and close the water jacket exhaust valve after the water jacket is full;

e. Adjust the water pressure in the water jacket to the set value through the water pressure control component installed on the water inlet pipeline;

f. Close the control valve of the water inlet pipeline to maintain a constant water pressure in the water jacket within the set time;

g. Open the drain valve of the water jacket, drain the water in the water jacket, cut off the water inlet pipe connected to the water jacket, and then cut open the outer protective pipe and insulation layer of the joint of the tested workpiece to check whether there is water seeping into the joint, and determine whether the joint of the tested workpiece meets the design requirements.

In the above-mentioned direct buried thermal insulation pipe joint water tightness test method, the water temperature injected into the water jacket is controlled within the range of 23±2°C, and a colorant is added to the water.

In the above-mentioned direct-buried insulated pipe joint water tightness test method, in the step e, the water pressure is controlled to be 30KPa, and in the step f, the constant pressure is maintained for no less than 24 hours.

The present invention provides a water tightness test device and a test method for a directly buried thermal insulation pipe joint, which can provide a high-pressure environment for a tested workpiece through a pressurized water jacket, and after the thermal insulation pipe joint is immersed in the water jacket and maintained in a constant pressure state for a certain period of time, the outer protective pipe and the thermal insulation layer of the joint part of the tested workpiece are cut open, and the sealing performance of the tested workpiece is judged by checking the water seepage of the thermal insulation layer, thereby achieving the purpose of ensuring product quality and reducing the operation and maintenance costs of the pipeline network.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the cross-sectional structure of a tested workpiece;

Fig. 2 is an enlarged view of the structure at position Ⅰ in Fig. 1;

FIG3 is a schematic diagram of a first embodiment of the present invention;

FIG4 is a schematic diagram of a second embodiment of the present invention;

5 is a schematic diagram of the sealing mechanism structure in the water tightness test equipment for direct buried thermal insulation pipe joints;

FIG. 6 is an enlarged view of the structure at point II in FIG. 5 .

Explanation of the symbols in the figure:

1 is the workpiece to be tested, 1-1 is the working steel pipe, 1-2 is the insulation layer, 1-3 is the outer protective pipe; 2 is the joint sleeve; 3 is the water jacket; 4 is the sealing mechanism, 4-1 is the inflatable sealing ring, 4-2 is the sealing ring fixing seat, 4-3 is the bolt assembly; 5 is the water injection port; 6 is the exhaust valve; 7 is the water pressure control assembly; 8 is the water inlet pipeline; 9 is the water tank; 10 is the drain valve; 11 is the workpiece bracket; 12 is the control valve, and 13 is the water pump.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Referring to Figures 1 and 2, a joint connection structure of a prefabricated direct-buried insulated pipe is shown, in which two sections of prefabricated direct-buried insulated pipe are connected by a sleeve joint 2. The sleeve joint 2 is made of a polyethylene sleeve with the same material and density as the outer protective pipe of the prefabricated insulated pipe. A heat shrink tape is used to connect and seal the polyethylene sleeve joint 2 and the outer protective pipe of the main pipe. For insulated pipes laid by direct burial, if there are sealing defects at the joints, the accumulated water in the stratum will penetrate into the insulation layer, corrode the outer wall of the working steel pipe, and have an adverse effect on the normal operation and maintenance of the pipe network. In order to avoid the above problems, according to the relevant technical standards for prefabricated direct-buried pipes, it is necessary to conduct a water sealing performance test on the joints of the direct-buried insulated pipes.

3 and 4, the present invention provides a water tightness test device for a direct-buried insulated pipe joint. The workpiece 1 to be tested is an insulated pipe with a complete joint in the middle part. The workpiece 1 to be tested is horizontally placed on a workpiece support 11; the water tightness test device for the direct-buried insulated pipe joint comprises a water jacket 3, a sealing mechanism 4, a water inlet pipeline 8 and a high-pressure water injection device; the water jacket 3 is made of steel plate and is a cylindrical structure made by a rolling welding process. It is sleeved on the joint part of the insulated pipe. The length of the water jacket 3 is greater than the length of the sleeve 2 of the insulated pipe joint. Sealing mechanisms 4 are provided at both ends of the water jacket 3, and the annular space between the two ends of the water jacket 3 and the outer protective tube 1-3 of the tested workpiece 1 is sealed by the sealing mechanism 4. A water injection port 5 and an exhaust valve 6 are arranged on the outer side wall of the water jacket 3, and the water injection port 5 and the exhaust valve 6 are located on both sides of the axial edge of the insulation pipe joint sleeve 2; one end of the water inlet pipeline 8 is connected to the water injection port 5 on the water jacket 3, and the other end is connected to the high-pressure water injection device. A control valve 12 and a water pressure control component 7 are arranged on the water inlet pipeline 8, and the water pressure control component includes a pressure regulating valve and a pressure gauge.

Referring to Figure 3, the water tightness test equipment for direct-buried insulated pipe joints described in the present invention, its first preferred embodiment is: the high-pressure water injection device is a water tank 9 installed at a set height, the water outlet of the water tank 9 is connected to the water inlet pipeline 8, and the installation height of the water tank 9 is determined according to the set value of the water pressure in the water jacket 3 in the water tightness test.

4 , the water tightness test equipment for direct-buried thermal insulation pipe joints of the present invention has a second preferred embodiment as follows: the high-pressure water injection device is a water pump 13 arranged on the water inlet pipeline 8 , and the water pump 13 is a constant-pressure water pump.

5 and 6, the water tightness test equipment for direct-buried thermal insulation pipe joints of the present invention, the sealing mechanism 4 includes an inflatable sealing ring 4-1, a sealing ring fixing seat 4-2 and a bolt assembly 4-3; the sealing ring fixing seat 4-2 is an annular support matching the inner diameter of the water jacket 3, and has an L-shaped cross-sectional structure, and its side wall is assembled with the water jacket 3 through the bolt assembly 4-3, and the inflatable sealing ring 4-1 is embedded on the bottom surface of the sealing ring fixing seat 4-2; the bolt assemblies 4-3 are evenly arranged in several groups along the circumference of the water jacket 3.

3 or 4, the present invention also provides a method for testing the water tightness of a direct-buried thermal insulation pipe joint, which uses the above-mentioned direct-buried thermal insulation pipe joint water tightness testing equipment to complete the water tightness test of the tested workpiece 1, and the operating steps are as follows:

a. Put the water jacket 3 on the outside of the tested workpiece 1. The tested workpiece 1 is two sections of insulation pipes connected in the middle by a joint sleeve 2. After the water jacket 3 is put on, the tested workpiece 1 is horizontally placed on the workpiece support 11;

b. Adjust the position of the water jacket 3 so that it completely covers the joint sleeve 2 on the tested workpiece 1, and then fill the inflatable sealing ring 4-1 with high-pressure gas. The inflatable sealing ring 4-1 expands to seal the annular space between the two ends of the water jacket 3 and the outer protective tube of the insulation pipe. The inflation pressure in the inflatable sealing ring 4-1 is greater than the set water pressure in the water jacket 3;

c. Connect the water injection port 5 on the water jacket 3 to the water inlet pipe 8;

d. Open the exhaust valve 6 of the water jacket 3 and the control valve 12 of the water inlet pipeline 8, inject high-pressure water into the water jacket 3, control the water temperature injected into the water jacket 3 within the range of 23±2°C, and add blue or red coloring agent into the water. After the water jacket 3 is filled and a water column is ejected from the exhaust valve 6, close the exhaust valve 6 of the water jacket 3;

e. Adjust the water pressure in the water jacket 3 to 30 KPa through the water pressure control assembly 7 provided on the water inlet pipeline 8;

f. Close the control valve 12 of the water inlet pipe 8 to maintain the water pressure in the water jacket 3 constant for at least 24 hours;

g. Open the drain valve 10 of the water jacket 3, drain the water in the water jacket 3, cut off the water inlet pipe 8 connected to the water jacket 3, and then cut open the outer protective tube 1-3 and the insulation layer 1-2 of the joint of the tested workpiece 1 to check whether there is water infiltration into the joint, and determine whether the joint of the tested workpiece 1 meets the design requirements.

Claims (10)

1. A water tightness test device of a direct-buried heat-insulating pipe joint is characterized in that a tested workpiece (1) is a heat-insulating pipe with a complete joint in the middle part, and the heat-insulating pipe is horizontally placed; the method is characterized in that: the water tightness test device of the direct-buried heat-preservation pipe joint comprises a water jacket (3), a sealing mechanism (4), a water inlet pipeline (8) and a high-pressure water injection device; the water jacket (3) is of a cylindrical structure and sleeved at the joint part of the heat preservation pipe, the length of the water jacket (3) is larger than that of the heat preservation pipe joint sleeve (2), sealing mechanisms (4) are assembled at two ends of the water jacket (3), annular spaces between two ends of the water jacket (3) and the outer protective pipe of the heat preservation pipe are sealed through the sealing mechanisms (4), a water filling port (5) and an exhaust valve (6) are arranged on the outer side wall of the water jacket (3), and the water filling port (5) and the exhaust valve (6) are positioned at two sides of the axial edge of the heat preservation pipe joint sleeve (2); one end of the water inlet pipeline (8) is connected with a water injection port (5) on the water jacket (3), the other end of the water inlet pipeline is connected with a high-pressure water injection device, and a control valve (12) is arranged on the water inlet pipeline (8).

2. The direct burial thermal pipe joint water tightness test apparatus according to claim 1, wherein: the water inlet pipeline (8) is provided with a water pressure control assembly (7), and the water pressure control assembly comprises a pressure regulating valve and a pressure gauge.

3. The direct burial thermal pipe joint water tightness test apparatus according to claim 2, wherein: the high-pressure water injection device is a water tank (9) arranged at a set height, and a water outlet of the water tank (9) is connected with a water inlet pipeline (8).

4. The direct burial thermal pipe joint water tightness test apparatus according to claim 2, wherein: the high-pressure water injection device is a water pump (13) arranged on the water inlet pipeline (8).

5. The direct burial thermal pipe joint water tightness test apparatus according to claim 3 or 4, wherein: the sealing mechanism (4) comprises an inflatable sealing ring (4-1), a sealing ring fixing seat (4-2) and a bolt component (4-3); the sealing ring fixing seat (4-2) is an annular support matched with the inner diameter of the water jacket (3) and is of an L-shaped section structure, the side wall of the sealing ring fixing seat is assembled with the water jacket (3) through a bolt assembly (4-3), and the bottom surface of the sealing ring fixing seat (4-2) is embedded with the inflatable sealing ring (4-1); the bolt assemblies (4-3) are uniformly distributed in a plurality of groups along the circumferential direction of the water jacket (3).

6. The apparatus for testing the water tightness of the direct burial thermal insulation pipe joint according to claim 5, wherein: the water jacket (3) is made of steel plates and is manufactured through a rolling welding process.

7. The apparatus for testing the water tightness of the direct burial thermal insulation pipe joint according to claim 5, wherein: the water jacket (3) is also provided with a water drain valve (10), and the water drain valve (10) is positioned at the bottom of the water jacket (3).

8. A water tightness test method for a direct-buried heat-insulation pipe joint is characterized by comprising the following steps of: the water tightness test of the tested workpiece (1) is completed by adopting the water tightness test equipment for the direct-buried heat-preservation pipe joint, and the operation steps are as follows:

a. sleeving the water jacket (3) outside the tested workpiece (1), and horizontally placing the tested workpiece (1) on the workpiece bracket (11);

b. The position of the water jacket (3) is adjusted to completely cover the joint sleeve (2) on the tested workpiece (1), then high-pressure gas is filled into the inflatable sealing ring (4-1), and the inflatable sealing ring (4-1) is inflated to seal the annular space between the two ends of the water jacket (3) and the outer protective tube of the heat preservation tube;

c. the water injection port (5) on the water jacket (3) is connected with the water inlet pipeline (8);

d. Opening an exhaust valve (6) of the water jacket (3) and a control valve (12) of the water inlet pipeline (8), injecting high-pressure water into the water jacket (3), and closing the exhaust valve (6) of the water jacket (3) after the water jacket (3) is full;

e. the water pressure in the water jacket (3) is adjusted to a set value through a water pressure control assembly (7) arranged on the water inlet pipeline (8);

f. closing a control valve (12) of the water inlet pipeline (8) to maintain constant water pressure in the water jacket (3) within a set time;

g. Opening a water drain valve (10) of the water jacket (3), evacuating water in the water jacket (3), cutting off a water inlet pipeline (8) connected with the water jacket (3), then cutting off an outer protective pipe (1-3) and an insulating layer (1-2) at the joint part of the tested workpiece (1), checking whether water permeates into the joint, and judging whether the joint of the tested workpiece (1) meets the design requirement.

9. The method for testing the water tightness of the direct burial thermal insulation pipe joint according to claim 8, wherein the method comprises the following steps: the water temperature injected into the water jacket (3) is controlled within the range of 23+/-2 ℃, and the coloring agent is added into the water.

10. The method for testing the water tightness of the direct burial thermal insulation pipe joint according to claim 8, wherein the method comprises the following steps: in the step e, the water pressure is controlled to be 30KPa, and in the step f, the constant pressure time is kept to be not less than 24 hours.