A method for installing a pressure stabilizing chamber unit

Abstract

A method for installing a pressure stabilizing chamber unit, wherein a semi-circular tube-shaped pressure stabilizing chamber segment is welded to an outer bottom plate in advance to form a pressure stabilizing chamber unit, wherein the pressure stabilizing chamber unit includes two end pressure stabilizing chamber units and a middle pressure stabilizing chamber unit. The outer bottom plate of the pressure stabilizing chamber unit is thickened downward by 10 mm, and a plurality of jet holes are opened on the outer bottom plate along the center line of the jet holes; after the jet holes are opened, the pressure stabilizing chamber segment is welded, and after the pressure stabilizing chamber segment is welded to the outer bottom plate, a plurality of pressure stabilizing chamber units are arranged in sequence and installed on the bottom inlet segment and the bilge segment. The welded pressure stabilizing chamber unit is subjected to a strength test at a pressure of 3.3 bar, and is qualified if the pressure is maintained for 30 minutes without pressure change. This method of the present invention can ensure the efficient construction of a real ship and meet functional requirements, while ensuring the welding quality between the pressure stabilizing chamber and the outer bottom plate, and can shorten the overall construction period to the greatest extent and improve the construction quality when installing in the large-scale segment assembly stage.

Description

Technical Field

[0001] The invention belongs to the technical field of ship gas drag reduction, and in particular relates to a method for installing a pressure stabilizing chamber unit. Background Art

[0002] Ship gas drag reduction technology is a technology that forms a stable gas lubrication layer by introducing air into the bottom of the ship during the ship's travel, thereby reducing the friction resistance of the ship's surface. The ship's air layer drag reduction system includes an air supply system, an air cavity and a jet hole. The jet hole is arranged on the bottom plate of the ship and is connected to the air cavity. When the ship is traveling, the air supply system supplies air into the air cavity, and the gas in the air cavity is ejected to the outside of the hull through the jet hole to form a gas lubrication layer on the bottom of the hull that can reduce resistance.

[0003] The bottom of the hull is arranged with structures such as a pressure stabilizing chamber, pads, baffles, cavitation coamings and bow and stern guide plates. The pressure stabilizing chamber is installed on the upper surface of the outer bottom plate to stabilize the air pressure during navigation and spray air into the seawater to form an air layer; pads, baffles, cavitation coamings and bow and stern guide plates are installed on the lower surface of the outer bottom plate to prevent the gas from escaping too quickly, maintain the flat bottom area of ​​the ship, and keep the air layer stable.

[0004] Since the pads, baffles, cavitation coamings and bow and stern guide plates are installed outside the bottom of the ship, these structures are not found on other ships and there is no installation method that can be used as a reference. In addition to meeting the normal hull construction related regulations, ships with air layer drag reduction systems still need to meet the following functional requirements, including:

[0005] (1) The surface of the narrow space structure inside the pressure stabilizing chamber and the guide plate needs to be painted for corrosion protection;

[0006] (2) Antifouling paint needs to be applied inside the jet hole;

[0007] (3) The pressure stabilizing chamber needs to be subjected to a pressure test at 1.5 times the maximum working pressure, and the pressure should be maintained for 30 minutes without any pressure change.

[0008] Therefore, the installation sequence of structures such as pads, baffles, cavitation panels and bow and stern guide plates is very critical. The present invention adopts a small unitized pressure stabilizing chamber structure instead of installation on large sections, which is a key technology for the actual construction and application of air layer drag reduction ships. Summary of the invention

[0009] In order to solve the above problems, the present invention provides a method for installing a pressure stabilizing chamber unit, aiming to shorten the overall construction period to the greatest extent and improve the construction quality. The technical solution adopted is:

[0010] A method for installing a pressure-stabilizing chamber unit comprises welding a semi-circular tube-shaped pressure-stabilizing chamber segment to an outer bottom plate in advance to form a pressure-stabilizing chamber unit, wherein the pressure-stabilizing chamber unit comprises two end pressure-stabilizing chamber units and a middle pressure-stabilizing chamber unit, wherein the middle pressure-stabilizing chamber unit is composed of a pressure-stabilizing chamber segment and an outer bottom plate, and the end pressure-stabilizing chamber unit is composed of a pressure-stabilizing chamber segment, an outer bottom plate and a sealing box, wherein a plurality of middle pressure-stabilizing chamber units are connected between the two end pressure-stabilizing chamber units, and the end pressure-stabilizing chamber units are connected to the middle pressure-stabilizing chamber unit in sequence to form a complete pressure-stabilizing chamber, and the sealing box is located at both ends of the pressure-stabilizing chamber and communicated with the inside of the pressure-stabilizing chamber.

[0011] The pressure stabilizing chamber unit is installed on the bottom incoming line segment and the bilge segment, and the length of the pressure stabilizing chamber unit is consistent with the width of the corresponding bottom incoming line segment and the bilge segment.

[0012] The specific operation method is as follows:

[0013] The outer bottom plate of the pressure stabilizing chamber unit is thickened 10mm downwards, and plate opening inspection lines and jet hole center lines are marked on the upper and lower surfaces of the outer bottom plate. The plate opening inspection lines are located at both ends of the outer bottom plate, marked along the width direction of the outer bottom plate, and 100mm away from the edge of the outer bottom plate. Multiple jet holes are opened on the outer bottom plate along the jet hole center line.

[0014] After the jet hole is opened, the pressure-stabilizing chamber segment is welded. The two ends of the pressure-stabilizing chamber segment are aligned with the plate mouth inspection line respectively, and the center line of the jet hole is aligned with the center line of the pressure-stabilizing chamber segment. The pressure-stabilizing chamber segment is raised by 4-5mm with a pad. The two pressure-stabilizing chamber units to be welded are placed back to back and sideways into the template tire. The template tire clamps one side of the two pressure-stabilizing chamber units to be welded, and the other sides of the two pressure-stabilizing chamber units to be welded are fixed by multiple pressure plates. After fixation, first weld one side of the pressure-stabilizing chamber segment to the outer bottom plate. After welding one side, turn the pressure-stabilizing chamber unit to be welded, and weld the other side of the pressure-stabilizing chamber segment to the outer bottom plate.

[0015] After the pressure stabilizing chamber sections are welded to the outer bottom plate, the baffles and pads are welded in sequence.

[0016] Use a hand winch to lift the pressure stabilizing chamber unit from bottom to top to a predetermined height, arrange multiple pressure stabilizing chamber units in sequence along the width direction of the hull, butt the ends of two adjacent pressure stabilizing chamber units, and install them on the bottom inlet section and bilge section.

[0017] Before installing the pressure-stabilizing chamber unit, first position the pressure-stabilizing chamber unit. In the direction of the ship's length, measure the distance between the center line of the jet hole and the segment reference network line. In the height direction, the free edge of the closing mouth of the pressure-stabilizing chamber unit is lowered by 3~4mm. Use the code plate to limit the height and length directions, and perform welding of the pressure-stabilizing chamber unit and the bottom inlet segment, bilge segment, and adjacent pressure-stabilizing chamber units.

[0018] After welding is completed, the excess height of the weld at the joint of adjacent pressure-stabilizing chamber units is ground off, and a pressure-stabilizing chamber adjustment tube is welded at the joint. The two ends of the pressure-stabilizing chamber adjustment tube are connected to the ends of the adjacent pressure-stabilizing chamber segments. The pressure-stabilizing chamber adjustment tube is welded to the outer bottom plate of the ship, and an outer jacket steel pipe is provided on the outside of the pressure-stabilizing chamber adjustment tube to finally form a complete pressure-stabilizing chamber. The code plate is removed after installation.

[0019] The welded pressure-stabilizing chamber unit is subjected to a strength test at a pressure of 3.3 bar. If there is no pressure change after maintaining the pressure for 30 minutes, it is qualified.

[0020] In the above-mentioned method for installing a pressure stabilizing chamber unit, further, the pressure stabilizing chamber and the outer bottom plate are positioned by CO2 welding.

[0021] The above-mentioned pressure stabilizing chamber unit installation method, further, the outer jacket steel pipe is equipped with an outer jacket steel pipe web, the two outer jacket steel pipe webs are respectively located at the two ends of the outer jacket steel pipe, the outer jacket steel pipe web is an annular plate, and its inner diameter coincides with the outer diameter of the pressure stabilizing chamber. The outer jacket steel pipe web is stuck on the outer surface of the pressure stabilizing chamber, and is welded and fixed to the pressure stabilizing chamber and the outer bottom plate of the ship, and the end of the outer jacket steel pipe is welded and fixed to the outer jacket steel pipe web.

[0022] The above-mentioned method for installing a pressure-stabilizing chamber unit further comprises the following steps: when the pressure-stabilizing chamber unit is subjected to a strength test, temporary sealing plates are welded at both ends of the pressure-stabilizing chamber segment, and sealing plugs are inserted into the jet holes. The sealing plugs are inserted into the jet holes from the back of the pressure-stabilizing chamber unit, and the sealing plugs are pressed by a pressure plate, and two C-shaped clamps symmetrically press the two ends of the pressure plate.

[0023] In the above-mentioned method for installing a pressure stabilizing chamber unit, further, the template is placed on the ground, a vertical long strip groove is opened on the top, and an arc-shaped notch is provided on one side of the opening of the groove, and the notch is adapted to the curvature of the outer surface of the pressure stabilizing chamber.

[0024] The above-mentioned method for installing a pressure stabilizing chamber unit further comprises the following steps: when the pressure stabilizing chamber unit is installed, a plurality of pairs of small tonnage lifting rings are installed on the outer bottom plate of the pressure stabilizing chamber unit, and each pair of small tonnage lifting rings are symmetrically installed on both sides of the pressure stabilizing chamber.

[0025] In the above-mentioned method for installing a pressure-stabilizing chamber unit, further, a baffle pad is fixed to the lower surface of the end pressure-stabilizing chamber unit.

[0026] In the above-mentioned method for installing a pressure-stabilizing chamber unit, further, a pressure gauge is provided on the outer sleeve steel pipe.

[0027] The above-mentioned pressure-stabilizing chamber unit installation method further comprises four middle pressure-stabilizing chamber units, the lengths of the two end pressure-stabilizing chamber units are respectively the same as the widths of the port bilge section and the starboard bilge section, and the lengths of the four middle pressure-stabilizing chamber units are respectively the same as the widths of the port side bottom section, the port middle bottom, the starboard middle bottom, and the starboard side bottom section.

[0028] The method of the present invention can ensure the efficient construction of the actual ship and meet the functional requirements, while ensuring the welding quality between the pressure-stabilizing chamber and the outer bottom plate of the ship. When installing in sections and large groups, the overall construction period can be shortened to the greatest extent and the construction quality can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the middle pressure stabilizing cavity unit;

[0030] Figure 2 Schematic diagram of the structure of the end pressure stabilizing cavity unit;

[0031] Figure 3 It is a schematic diagram of the pressure stabilizing chamber unit installed on the bottom inlet section and the bilge section;

[0032] Figure 4 It is a schematic diagram of marking the plate opening inspection line and the center line of the jet hole on the outer bottom plate of the ship;

[0033] Figure 5 It is a schematic diagram of the installation of the pressure stabilizing chamber unit;

[0034] Figure 6 It is a schematic diagram of the structure of the pressure stabilizing chamber unit to be welded being welded on the template;

[0035] Figure 7 It is a schematic diagram of the sealing test of the pressure stabilizing chamber unit;

[0036] Figure 8 It is a schematic diagram of limiting the pressure stabilizing cavity unit by using a code plate;

[0037] Fig. 9 It is a schematic diagram of lifting the pressure stabilizing chamber unit upward;

[0038] Fig.10 It is a schematic diagram of the docking installation of adjacent pressure stabilizing cavity units;

[0039] Fig.11 Installation diagram of the steel pipe for the pressure stabilizing chamber jacket;

[0040] Among them, 1-pressure stabilizing chamber segment, 2-outer bottom plate, 3-jacket steel pipe, 4-jacket steel pipe web, 5-pressure stabilizing chamber adjustment tube, 6-code plate, 7-pad, 9-plywood, 11-sealing box, 12-baffle, 13-port bilge, 14-port side bottom, 15-port middle bottom, 16-starboard middle bottom, 17-starboard side bottom, 18-starboard bilge, 19-template, 20-pressure plate, 22-C-type fixture, 23-sealing plug, 24-hand winch, 25-lifting ring, 26-plate mouth inspection line, 27-jet hole center line, 28-longitudinal section line, 29-pressure stabilizing chamber unit. DETAILED DESCRIPTION

[0041] The pressure stabilizing chamber unit includes the end pressure stabilizing chamber unit and the middle pressure stabilizing chamber unit. A ship is equipped with two end pressure stabilizing chamber units and four middle pressure stabilizing chamber units. The overall length of the pressure stabilizing chamber is 53.6m, which is divided into 6 pressure stabilizing chamber units. These 6 units are divided according to the segment width, from left to right, 7m, 9m, 12.6m, 9m, 9m, 7m. The length of the same annular segment is uniformly 22m.

[0042] The middle pressure stabilizing chamber unit is composed of the pressure stabilizing chamber segment and the outer bottom plate (such as Figure 1 The end pressure stabilizing chamber unit is composed of a pressure stabilizing chamber segment, an outer bottom plate and a sealing box (as shown in Figure 2 As shown in the figure, baffles and pads are welded on the outer bottom plate of the end pressure-stabilizing chamber unit. Since the internal painting of the pressure-stabilizing chamber is carried out during the manufacturing stage of the pressure-stabilizing chamber unit, the baffle pad structure under the outer bottom plate should be welded before the pressure-stabilizing chamber unit is painted to avoid damage to the paint inside the pressure-stabilizing chamber by subsequent hot work. A plurality of middle pressure-stabilizing chamber units are connected between the two end pressure-stabilizing chamber units. The end pressure-stabilizing chamber units are connected to the middle pressure-stabilizing chamber units in sequence to form a complete pressure-stabilizing chamber. The sealing box is located at both ends of the pressure-stabilizing chamber and is connected to the inside of the pressure-stabilizing chamber. Sealing boxes are added at both ends of the pressure-stabilizing chamber for the entry and exit of the spray trolley during the closing stage. Since the sealing box structure is welded to the outside of the semicircular tube of the pressure-stabilizing chamber, it also needs to be installed during the manufacturing of the pressure-stabilizing chamber unit.

[0043] like Figure 3 As shown in the figure, the semicircular tube type pressure stabilizing chamber is arranged along the ship width direction, spanning 6 sections from port to starboard. Since the pressure stabilizing chamber unit needs to be installed in the section assembly stage, the size of each pressure stabilizing chamber unit in the ship width direction should be equivalent to the section width size. In the ship length direction, the natural plate seam between the thickened outer bottom plate and the ordinary outer bottom plate is used as the boundary. The two end pressure stabilizing chamber units correspond to the port bilge section and the starboard bilge section respectively, and the multiple middle pressure stabilizing chamber units correspond to the port side bottom section, the port middle bottom, the starboard middle bottom, and the starboard side bottom section respectively.

[0044] like Figure 4 As shown in the figure, before the pressure stabilizing chamber is welded to the outer bottom plate, the plate opening inspection line and the center line of the jet hole are drawn on the outer bottom plate. The plate opening inspection line is located at both ends of the outer bottom plate, drawn along the width direction of the outer bottom plate, 100mm away from the edge of the outer bottom plate, and multiple jet holes are opened on the outer bottom plate along the center line of the jet hole. The outer bottom plate under the pressure stabilizing chamber needs to have jet holes, which weakens the strength of the outer bottom plate. In order to increase the corrosion allowance of the outer bottom plate and compensate for the strength loss caused by the opening, the outer bottom plate of the pressure stabilizing chamber unit is thickened by 10mm, and there is a natural plate seam with the normal outer bottom plate.

[0045] After the jet hole is opened, weld the pressure stabilizing chamber segment. The two ends of the pressure stabilizing chamber segment are aligned with the plate opening inspection line, and the center line of the jet hole is aligned with the center line of the pressure stabilizing chamber segment. Figure 5 ,6 As shown, the pressure-stabilizing chamber is raised by 4-5mm in sections with pads, and the two pressure-stabilizing chamber units to be welded are placed back to back and sideways into the template tire. The template tire clamps one side of the two pressure-stabilizing chamber units to be welded, and the other sides of the two pressure-stabilizing chamber units to be welded are fixed by multiple pressure plates. The template tire is placed on the ground, and a vertical long strip groove is opened on the top. There is an arc-shaped notch on one side of the opening of the groove, and the notch is adapted to the curvature of the outer surface of the pressure-stabilizing chamber.

[0046] After fixing, first weld one side of the stabilizing chamber segment to the outer bottom plate. After welding one side, turn the stabilizing chamber unit to be welded and weld the other side of the stabilizing chamber segment to the outer bottom plate. Use CO2 welding for positioning welding. During the positioning welding process, gradually remove the pad under the stabilizing chamber segment. Gradually remove the pad and weld from one end. While welding, extract the pad and gradually move the pad in the opposite direction. Until the welding is completed.

[0047] According to the specification requirements, the welded pressure stabilizing chamber unit is subjected to strength test at 3.3 bar pressure. Figure 7 As shown, when the pressure-stabilizing chamber unit is subjected to the strength test, temporary sealing plates are welded at both ends of the pressure-stabilizing chamber segment of the middle pressure-stabilizing chamber unit, and temporary sealing plates are welded on the side of the end pressure-stabilizing chamber unit away from the sealing box, and the other end is sealed with the manhole cover on the sealing box. Insert the sealing plug into the jet hole, and insert the sealing plug into the jet hole from the back of the pressure-stabilizing chamber unit. Press the sealing plug with a pressure plate, and press the two ends of the pressure plate symmetrically with two C-shaped fixtures to prevent the sealing plug from flying out during the strength test. Maintaining the pressure for 30 minutes without pressure change is qualified. Since it is difficult to repair during the closing stage, it is necessary to complete the strength test of the pressure-stabilizing chamber unit during the production stage of the pressure-stabilizing chamber unit.

[0048] When installing the pressure stabilizing chamber unit, install a small tonnage lifting ring at the appropriate position of the pressure stabilizing chamber unit. For a 14m long pressure stabilizing chamber unit, the number of lifting rings should be appropriately increased. Use a hand winch to lift the pressure stabilizing chamber unit from bottom to top to the predetermined height, such as Fig. 9 shown.

[0049] During positioning, in the length direction, measure the distance between the center line of the jet hole and the segmented reference network line to position the stabilizing chamber unit; in the height direction, the free edge of the closing mouth of the stabilizing chamber unit is lowered 3~4mm for positioning to make welding reverse deformation. After positioning, use the code plate to limit the height and length directions (such as Figure 8 As shown), start welding to complete the installation of the main structure of the pressure-stabilizing chamber unit, and remove the code plate after installation.

[0050] like Fig.10As shown in the figure, at the position crossing the segmented seam, a part of the pressure stabilizing cavity needs to be used as an adjustment pipe and installed during the closing stage. Before installation, grind off the excess height of the butt weld of the outer bottom plate under the pressure stabilizing cavity, complete the fillet weld between the pressure stabilizing cavity adjustment pipe and the outer bottom plate and the butt seam between the pressure stabilizing cavities, and penetrate the entire pressure stabilizing cavity. The web of the outer jacket steel pipe ensures the strength when the two sections are closed. An outer jacket steel pipe is added outside the pressure stabilizing cavity unit for alternative strength tests, and the web of the outer jacket steel pipe needs to be installed during the production stage of the pressure stabilizing cavity unit.

[0051] When constructing in sections, the length of the sections in the same ring section where the pressure stabilizing cavity is installed should be controlled and uniformly marked to avoid excessive deviation in the length of the sections in the same group, which will affect the straightness of the pressure stabilizing cavity after installation. After the sections are completed, the length of the sections is tested to ensure the straightness of the pressure stabilizing cavity as the starting point, and the divisions are cut and trimmed. Figure 3 As shown, the same ring segment of the pressure stabilizing cavity is divided. For precision control, each ship needs to mark the segment in advance, mainly for positioning, transverse section line, longitudinal section line, plate mouth inspection line, etc. This section means that the lines of this ring segment need to be drawn together, otherwise some segments are a little short and the precision control is not good during reassembly, which may cause the pressure stabilizing cavity to be not in a straight line. Draw them together when drawing, so that they are in a straight line when combined.

[0052] During the closing stage, when the pressure stabilizing chamber is completely connected, it is a lot of work to block all the jet holes and then conduct strength tests, so only the strength test of the pressure stabilizing chamber adjustment pipe is considered. After the adjustment pipe is installed, an outer steel pipe is added to the outside of the adjustment pipe, and the outer steel pipe is subjected to strength tests to replace the strength test of the adjustment pipe. The outer steel pipe is permanently retained and not removed. Ensure that the strength test is carried out at all locations of the entire pressure stabilizing chamber to meet the requirements of the specifications.

Claims

1. A method for installing a pressure stabilizing chamber unit, characterized in that: The semi-circular tube-shaped pressure stabilizing chamber segment (1) is welded to the outer bottom plate (2) in advance to form a pressure stabilizing chamber unit; the pressure stabilizing chamber unit comprises two end pressure stabilizing chamber units and a middle pressure stabilizing chamber unit, the middle pressure stabilizing chamber unit is composed of the pressure stabilizing chamber segment and the outer bottom plate, the end pressure stabilizing chamber unit is composed of the pressure stabilizing chamber segment, the outer bottom plate and a sealing box (11), a plurality of middle pressure stabilizing chamber units are connected between the two end pressure stabilizing chamber units, the end pressure stabilizing chamber units and the middle pressure stabilizing chamber units are connected in sequence to form a complete pressure stabilizing chamber, and the sealing box is located at both ends of the pressure stabilizing chamber and is connected to the inside of the pressure stabilizing chamber; The pressure stabilizing chamber unit is installed on the bottom incoming line segment and the bilge segment, and the length of the pressure stabilizing chamber unit is consistent with the width of the corresponding bottom incoming line segment and the bilge segment; The specific operation method is as follows: The outer bottom plate of the pressure stabilizing chamber unit is thickened downward by 10 mm, and a plate opening inspection line (26) and a jet hole center line (27) are drawn on the upper and lower surfaces of the outer bottom plate. The plate opening inspection line is located at both ends of the outer bottom plate, drawn along the width direction of the outer bottom plate, and is 100 mm away from the edge of the outer bottom plate. A plurality of jet holes are opened on the outer bottom plate along the jet hole center line; After the jet hole is opened, the pressure stabilizing chamber segment is welded, the two ends of the pressure stabilizing chamber segment are respectively aligned with the plate opening inspection line, the center line of the jet hole is aligned with the center line of the pressure stabilizing chamber segment, the pressure stabilizing chamber segment is raised by 4-5 mm with a cushion block (7), the two pressure stabilizing chamber units to be welded are placed back to back and sideways into the template, the template (19) clamps one side of the two pressure stabilizing chamber units to be welded, and the other sides of the two pressure stabilizing chamber units to be welded are fixed by multiple clamping plates (9), after being fixed, first one side of the pressure stabilizing chamber segment is welded to the outer bottom plate, after one side is welded, the pressure stabilizing chamber unit to be welded is turned, and the other side of the pressure stabilizing chamber segment is welded to the outer bottom plate (2); After the pressure stabilizing chamber sections are welded to the outer bottom plate, the baffle plate (12) and the pad plate are welded in sequence; Using a hand chain hoist (24), the pressure stabilizing chamber unit is lifted from bottom to top to a predetermined height, and multiple pressure stabilizing chamber units are arranged in sequence along the width direction of the hull, and the ends of two adjacent pressure stabilizing chamber units are butted, and installed on the bottom inlet section and the bilge section; Before installing the pressure stabilizing chamber unit, the pressure stabilizing chamber unit is first positioned. In the ship length direction, the distance between the center line of the jet hole and the segment reference network line is measured. In the height direction, the free edge of the closing opening of the pressure stabilizing chamber unit is lowered by 3 to 4 mm. The code plate (6) is used to limit the height and length directions. The pressure stabilizing chamber unit and the bottom inlet segment, the bilge segment welding, and the welding of adjacent pressure stabilizing chamber units are carried out. After the welding is completed, the excess height of the weld bead at the joint of adjacent pressure stabilizing chamber units is ground off, and a pressure stabilizing chamber adjustment tube (5) is welded at the joint, and the two ends of the pressure stabilizing chamber adjustment tube are butted with the ends of the adjacent pressure stabilizing chamber segments, and the pressure stabilizing chamber adjustment tube is welded to the outer bottom plate of the ship, and a jacket steel pipe (3) is provided on the outside of the pressure stabilizing chamber adjustment tube, and finally a complete pressure stabilizing chamber is formed, and the code plate (6) is removed after installation; The welded pressure-stabilizing chamber unit is subjected to a strength test at a pressure of 3.3 bar. If there is no pressure change after maintaining the pressure for 30 minutes, it is qualified.

2. A method for installing a pressure stabilizing chamber unit according to claim 1, characterized in that: The pressure stabilizing chamber and the outer bottom plate are welded by CO2 positioning.

3. A method for installing a pressure stabilizing chamber unit according to claim 1, characterized in that: The outer jacket steel pipe is matched with an outer jacket steel pipe web (4), and the two outer jacket steel pipe webs are respectively located at the two ends of the outer jacket steel pipe. The outer jacket steel pipe web is an annular plate, and its inner diameter is consistent with the outer diameter of the pressure stabilizing cavity. The outer jacket steel pipe web is clamped on the outer surface of the pressure stabilizing cavity and is welded and fixed to the pressure stabilizing cavity and the outer bottom plate. The end of the outer jacket steel pipe is welded and fixed to the outer jacket steel pipe web.

4. A method for installing a pressure stabilizing chamber unit according to claim 1, characterized in that: When the pressure stabilizing chamber unit is subjected to a strength test, temporary sealing plates are welded at both ends of the pressure stabilizing chamber segment, a sealing plug (23) is inserted into the jet hole, and the sealing plug is inserted into the jet hole from the back of the pressure stabilizing chamber unit. The sealing plug is pressed by a pressing plate (20), and two C-shaped fixtures (22) symmetrically press the two ends of the pressing plate.

5. A method for installing a pressure stabilizing chamber unit according to claim 1, characterized in that: The template tire (19) is placed on the ground, and a vertical long strip groove is formed on the top. An arc-shaped notch is provided on one side of the opening of the groove, and the notch is adapted to the arc of the outer surface of the pressure-stabilizing cavity.

6. A method for installing a pressure stabilizing chamber unit according to claim 1, characterized in that: When the pressure stabilizing chamber unit is installed, a plurality of pairs of small tonnage lifting rings (25) are installed on the outer bottom plate of the pressure stabilizing chamber unit, and each pair of small tonnage lifting rings is symmetrically installed on both sides of the pressure stabilizing chamber.

7. A method for installing a pressure stabilizing chamber unit according to claim 1, characterized in that: A baffle plate (12) and a pad are fixed to the lower surface of the end pressure stabilizing chamber unit.

8. A method for installing a pressure stabilizing chamber unit according to claim 1, characterized in that: A pressure gauge is provided on the outer jacket steel pipe.

9. A method for installing a pressure stabilizing chamber unit according to claim 1, characterized in that: There are four middle pressure stabilizing chamber units, the lengths of the two end pressure stabilizing chamber units are respectively the same as the widths of the port bilge (13) segment and the starboard bilge (18) segment, and the lengths of the four middle pressure stabilizing chamber units are respectively the same as the widths of the port side bottom (14) segment, the port middle bottom (15), the starboard middle bottom (16), and the starboard side bottom (17) segment.

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