CB/T 3617-1994 Quality requirements for special coatings of pipe systems and accessories
Some standard content:
Shipbuilding Industry Standard of the People's Republic of China
CB/T3617-94
Quality Requirements for Special Coating of Pipe Systems and Their AccessoriesPublished on April 11, 1994
China State Shipbuilding Corporation
Implementation on October 1, 1994
Shipbuilding Industry Standard of the People's Republic of China
Quality Requirements for Special Coating of Pipe Systems and Their AccessoriesSubject Content and Scope of Application
This standard specifies the quality requirements for the design, production and installation of special coatings for pipes and their accessories. CB/T3617-94
Classification Number: U06
This standard applies to pipes and pipe system accessories that require special coatings as specified in ship specifications. It can also be used as a reference for valves and other accessories (expansion joints, filters, etc.).
2 Design and production requirements
2.1 All pipes and accessories that are in direct contact with liquid cargo and are made of carbon steel materials must be specially coated (hereinafter referred to as special coating). 2.2 The pipe number, diameter, and length of each pipe must be listed for special coating, and the inner and outer surface areas and actual length of the pipe must be indicated, as well as drawings of pipe system accessories that require special coating. List the list and special coating area, and be countersigned by the special coating professional department. 2.3 Design and production requirements for special coating pipes
2.3.1 The length of any pipe that requires special coating should be less than 8m. The design of special coating pipes is only allowed to have one bending direction, and the angle must not be less than 90°, according to Figure 1 and Table 1.
Pipe diameter
≥300
≥400
90~135
2.3.2 When using finished elbows or finished tees, the distance between the butt weld and the flange surface shall meet the following requirements: a.
The distance between the weld with a diameter of DN50~200mm and the flange surface shall not exceed 1.5DN (pipe diameter); the distance between the weld with a diameter of DN200mm and above and the flange surface shall not exceed 2DN. mm
2.3.3 Pipe supports are divided into two types: movable type and fixed type. The movable type of pipe support is used in the part that does not bear the impact force, see Table 2; the fixed type of pipe support is divided into the following types according to the installation position and the size and direction of the bearing force, see Table 3. Table 2
Moveable pipe support
Figure Fixed type
Pipe support
Allowable load
Note: The "allowable load" in the table is for reference only. 2
Type of pipe support
Applicable parts
Straight pipe
Bend
Oil transfer station
CB/T3617-94
2.3.4 In order to prevent excessive liquid flow impact, fixed pipe supports and seats should be installed at the following locations: a. Corner of suction pipe;
b. Corner of vertical input pipe. 2.3.5 The pipe section where the pipe support is installed (the pipe that needs to be specially coated outside) should be equipped with anti-scratch strips, see Figure 2. The anti-scratch strips should be reflected in the pipe processing data sheet and connected in advance in the field, and specially coated together with the pipe. Weak spreading strips
Figure 2 Relative position of anti-scratch strips and pipe flanges 2.3.6 Specially coated flange connection bolts, nuts and pipe support fastening bolts, nuts and pipe instrument joints should be made of stainless steel with a carbon content of no more than 0.08%.
2.3.7 Manufacturing of pipes and accessories
2.3.7.1 Pipes must be manufactured strictly according to the processing data sheet. 2.3.7.2 Pipe welding should meet the following requirements: a. When the wall thickness of the pipe and the high-foot flange, reducer, elbow, etc. is greater than 6mm, a groove must be opened; b. After welding, the spatter and weld flow of the pipe must be cleaned and the weld must be smoothed. After grinding, the protruding height of the weld surface should not exceed 3mm, and it must be a smooth transition (good hand feel);
C. Butt welds should be filmed and inspected according to the requirements of the specification. 2.3.7.3 The non-verticality of the pipe end cut should not be greater than 1mm, the surface roughness is 300um, and the instrument pipe joint opening should be mechanically drilled.
2.3.7.4 The distance between the two welds should be greater than 50mm. 2.3.7.5 When cutting and manufacturing the accessories used for special coated pipes, the outer surface damage is not allowed. If it occurs, it should be polished smooth. 2.3.7.6 All sharp corners on pipe system accessories must be welded with double-sided welding. If this is not possible, welding grooves should be opened on the outside, and single-sided welding and double-sided forming welding processes should be adopted, and the welds should be smooth. 2.3.7.7 All sharp corners of accessories must be ground, and the fillet radius should not be less than 3mm. 2.4 Scope and requirements of pre-special coating of pipes and accessories: 2.4.1 The thickness and paint type of the coating should meet the requirements of the specifications and the shipowner. 2.4.2 The pipes on the deck and in the pump room are only specially coated inside, and the outer surface should be painted with the paint of the installation location. 2.4.3 For cargo oil pipes in cargo oil tanks, in addition to the special coating on the inner surface, the outer surface is first specially coated within the 200mm range of the pipe support position and within the 400mm range of the fixed range. After inspection, if the paint film is cured, it should be wrapped for protection. 2.4.4 The inner and outer surfaces of the pipes are rust-free by sandblasting, and the surface roughness is 30~100μm. For pipes with a diameter of DN80 or above, the inner surface shall be sprayed mechanically according to 3
CB/T3617-94
, and for pipes with a diameter of DN80 or below, the inner surface shall be sprayed by dipping or pouring. 2.4.5 For pipe fittings, pipe brackets, blind flanges, suction ports, etc. in the pipe system accessories, they shall be sandblasted after being checked to meet the requirements of special coating before they can be pre-specially coated.
2.4.6 For the welding part between the pipe bracket and the hull structure, except for the pre-specially coated part, a margin of 50 to 100 mm shall be left for temporary primer. As shown in Figure 3.
Pre-specially coated part
50-100
2.4.7 The flanges at both ends of the pipes that have been pre-specially coated must be sealed and wrapped. 3 Special coating and installation requirements
3.1 The procedures for pipe installation and hull bulkhead special coating must be arranged according to the specific construction conditions of each factory. In general, the special coating installation process is shown in Table 4. When the hull bulkhead is specially coated, the root of the pipe support, the pipe and the outer wall of the through-piece are specially coated at the same time. 3.2 After all pipe supports in the special coating area are welded to the hull, the welds must be polished and smooth. 3.3 Pipes that have been specially coated cannot be cut, drilled, welded, etc. If modification is necessary, they should be re-specially coated. For small-diameter instrument pipe joints, remove the pipes, drill holes and grind off burrs with machinery, remove iron filings, and then perform local re-coating after welding. 3.4 If the flatness of bulkhead plates, decks, and inner bottom plates exceeds the tolerance requirements of the hull construction, they should be corrected by pyrotechnics before installing through-tank pipe fittings. 3.5 When installing through-tank pipe fittings, the pre-special coating should be prevented from being burned during welding. 4 Inspection rules
4.1 If the tightness test is difficult to arrange with the special coating of the hull bulkhead, it is allowed to be tested in sections. During the test, attention must be paid to checking the firmness of the pipe supports at the corners, before and after the expansion joints, and other fixed pipe supports. 4.2 Pipes and accessories that require special coating: marine flanges, nuts, gaskets, pipe joints and other materials must all have certificates of conformity. 4.3 For butt welds, according to the requirements of ship construction specifications, non-destructive testing shall be used to check the welding quality as appropriate. 4.4. According to the special coating requirements, check the special coating coverage quality, paint film thickness and uniformity. Special coating installation process
Pipe production (according to the layout data table)
Pipe accessories, pipe brackets, trade, etc.
Pipe special coating, business brackets, fees
Pipe accessories pre-special coating
Health care, wrapping
Pallet loading, traffic pipe installation class
Sectional installationbzxz.net
On-site pipe trial installation, heating coil
Bottom trial installation, general side installation
On-site pipe welding
The second batch of pipe special coating
On-site pipe installation
Pipe system test area
Large cabin special coating
CB/T3617--94
Special coating installation process
Pipe bracket special coating
Large combination
Special image,| |tt||Stop code
Special edge range
Maintenance package hole
Side identification and inspection
Special coating and polishing, dripping special coating requirements
Single pipe calibration, pressure test and inspection
Inner surface (including flange surface) special flow outer
Surface: special coating of pipe brackets in the cabin,
Temporary primer pump cabin 1205 second degree;
Upper deck 4633-degree
Pipe mouth, flange surface, pipe bracket wrapping
Check pipes and other parts and inventory
Store away from sun and rain
Transport, lifting and installation comply with regulations
Welding pipe brackets, connecting flanges, pipe brackets to be painted, enclosed pipe bracket welding,
On-site pipe flange positioning. Heating on the glue side
Coil welding
Special coating
Special coating on the inner surface (including flange bacteria).
Special coating on the outer surface of the cabin pipe bracket, mooring cabin
1205 second degree, upper deck 4633 degree
Connect all flanges and pipe brackets
Hull structure damaged by welding, repaired
Insulation, welding and grinding of pipe system, comprehensive inspection, surface without special coating, good wrapping
Scaffolding special coating before final inspection
Additional instructions:
This standard is proposed by China State Shipbuilding Corporation. CB/T3617-94
This standard is under the jurisdiction of the 603 Institute of China State Shipbuilding Corporation. This standard is drafted by Guangzhou Shipyard. The drafters of this standard are Jin Guanlin and Dong Bigen.
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