This standard specifies the inspection, repair, test and acceptance requirements for marine Freon piston refrigeration compressors. This standard applies to marine small and medium-sized Freon piston refrigeration compressors using R12 and R22 as refrigerants. This standard does not apply to refrigerated transport ships and cargo hold refrigeration compressors. CB/T 3710-1995 Technical Requirements for Repair of Marine Freon Piston Refrigeration Compressors CB/T3710-1995 Standard Download Decompression Password: www.bzxz.net

Shipbuilding Industry Standard of the People's Republic of China
CB/T3710—1995
Marine Freon Piston Refrigeration Compressor
Repair Technical Requirements
Published on December 19, 1995
Published by China State Shipbuilding Corporation
Implemented on August 1, 1996
Shipbuilding Industry Standard of the People's Republic of China
Marine Freon Piston Refrigeration Compressor
Repair Technical Requirements
1 Subject Content and Scope of Application
CB/T3710—1995
Classification Number: R32
This standard specifies the inspection, repair, test and acceptance requirements for marine Freon piston refrigeration compressors (hereinafter referred to as compressors). This standard applies to small and medium-sized marine Freon piston refrigeration compressors using R12 and R22 as refrigerants. This standard does not apply to refrigerated transport ships and cargo hold refrigeration compressors. 2 Reference standards
GB1184 Shape and position tolerances Provisions for unmarked tolerances JB3709 Technical conditions for marine Freon single-stage refrigeration compressors CB3378 Technical requirements for repairs of marine refrigeration and air conditioning refrigeration equipment 3 Inspection
3.1 Scope of inspectionbZxz.net
3.1.1 For minor repairs, only the parts within the scope of repair specified by the ship shall be disassembled for inspection. 3.1.2 For the whole machine repair project, the pre-repair test shall be carried out first, and then the disassembly inspection shall be carried out. 3.2 Pre-repair test
3.2.1 The pre-repair test shall be carried out in one of the following ways: sailing with the ship, pre-repair sea trial or pre-repair mooring test. 3.2.2 Perform the utility operation test under full load conditions of the unit. Observe and understand the pre-repair technical status of the unit. For abnormal conditions and technical failures that occur during the test, key tests shall be carried out, and comprehensive inspections and detailed records shall be carried out. 3.3 Disassembly inspection
3.3.1. After the compressor is disassembled, effective measures should be taken to thoroughly clean all parts. Then check each component, focusing on comprehensive and careful inspection of moving wear parts and main load-bearing parts, and make detailed inspection records. 3.3.2 Check the main load-bearing parts such as crankshaft, piston, connecting rod, piston pin, connecting rod bolt, etc. for defects such as serious deformation and cracks. Non-destructive testing should be carried out on key load-bearing parts such as crankshaft and connecting rod bolts when necessary. 3.3.3 The cooling water cavity should be subjected to a water pressure test with a test pressure of 0.6MPa and a pressure maintenance of 5min to check the leakage of all relevant parts. 4 Repair
4.1 Cylinder, piston and piston ring
4.1.1 The installation clearance of the cylinder and piston should comply with the provisions of Table 1. When the use limit value is exceeded, the piston or cylinder should be replaced, or both should be replaced with new ones.
Approved by China State Shipbuilding Corporation on December 19, 1995, implemented on August 1, 1996
CB/T3710-1995
Clearance table of cylinder and piston
0.18~0.24
0.16~0.20
0.12~0.18
0.12~0.15
0.125~0.175
0.025~0.045
0.13~0.17
Use limit value
When the working surface of the cylinder or piston has a small amount of wear (the installation clearance is less than the use limit value in Table 1) or slight burrs and scratches, it is allowed to continue to be used after manual repair to eliminate the defects. 4.1.3 When the working surface of the cylinder has serious defects such as roughening and scratches, machining measures such as turning, boring and grinding can be used to eliminate the defects. When the increment of the cylinder diameter after machining is greater than 0.5% of the nominal diameter, a hydraulic strength test should be carried out; when the increment is greater than 1% of the nominal diameter, it should be replaced.
4.1.4 After the piston ring groove is worn, it is allowed to repair it by polishing the ring groove and preparing a new piston ring. However, the increment of the axial size of the ring groove shall not be greater than 10% of the nominal size of the ring groove. When the opening clearance and axial clearance of the piston ring exceed the use limit values ​​specified in Table 2, the piston ring should be replaced. After installation, it must meet the installation clearance range. 4.1.5

Piston ring opening clearance and piston ring end face clearance
Installation clearance
0.40~0.60
0.40~0.60
0.25~0.40
0.10~0.25
Use limit value
Piston ring end face clearance
Installation clearance
0.018~0.055
0.025~0. 065 | | tt | 0.02~0.04
Use limit value
4.2 crankshaft
CB/T 3710---1995
4.2.1 When the main journal or crank pin working surface has minor defects such as burrs and scratches, manual repair can be used. It is allowed to continue to be used after the defects are eliminated.
4.2.2 When the thickness or wear resistance of the main journal or crank pin exceeds the requirements of Table 3 or the working surface has serious defects such as burrs, scratches or corrosion, it is allowed to be repaired by machining or pre-processing methods such as turning and separation, but the reduction in diameter after processing shall not exceed 2% of the nominal inch. It can also be repaired by heat treatment and reliable process methods such as plating, electric keying, or metal spraying. Table 3 The main journal or crank pin has a diameter and columnar difference of zero
4.3 Main bearing and connecting rod bearing
8 current precision seat specifications in GB1184
Use the extreme service value
8 precision specifications in GB1184 twice 4.3.1 If there are slight burrs or secondary marks on the working surface of the bearing, it can be manually scraped and trimmed. 4.3.2
When the bearing surface is seriously roughened, scratched or the alloy is peeled, it should be replaced. 4.33 When rolling bearings are used as main bearings, if the main bearings are overheated, rusted, shaved, parts damaged, or serious defects such as excessive gaps due to obvious damage to the working surface, they must be replaced frequently. 4.3.4 When sliding auxiliary bearings are used, the matching intervals should comply with the provisions of Tables 4 and 5. When the installation clearance exceeds the limit, the crankshaft should be restored to the original nominal value or replaced with a new crankshaft. When the crankshaft is installed in the main bearing, the thrust clearance should be 0.751.50mm. Table 4 Typical shaft and main bearing clearance
0. 0750.115
0. 050. 07
0. 04~0. 055
C. 035--0.065
0, 02~-0, c5
Convenient frequency limited sale
4.4 Connecting rod and piston pin
CB/T3710---1995
Table 5 Crank pin and connecting rod big end bearing clearance Crank and connecting rod big end bearing
Nominal diameter
The clearance between the connecting rod small end bearing and the piston pin shall comply with the requirements of Table 6.
0.070~0.115
0.05~0.07
0.05~0.07
0.03~0.06
0.03~0.05
Table 6 Connecting rod small end bushing Matching clearance with piston pin Connecting rod bushing and piston pin
4.5 Shaft seal
Nominal diameter
Installation clearance
0.015~0.035
0.01~0.03
0.01~0.037
0.01~0.025
0.01~0.025
0.015~0.025
Use limit value
Use limit value
When the friction ring of the crankshaft shaft seal is seriously worn or damaged, and the rubber sealing ring is aged or worn, it should be replaced. After the shaft seal is repaired and run-in, for the shaft seal of the compressor with a cooling capacity not exceeding 35kW, a slight leakage of 4.5.2
is allowed in the working state, but no oil dripping is allowed. For compressors with a cooling capacity greater than 35kW, the oil dripping shall not exceed 0.5mL/h. 5
Self-made parts
The parts shall be manufactured in accordance with the product drawings and technical documents. If there are no drawings, they shall comply with the provisions of JB3709. 6 Test and acceptance
6.1 Installation and adjustment before operation test
CB/T3710-1995
6.1.1 The cooling water chamber shall be subjected to a water pressure tightness test. The test pressure is 0.6MPa, maintain pressure for 5min, no leakage. 6.1.2 The clearance between the piston and the cylinder head valve plate shall comply with the provisions of Table 7. Table 7 Clearance between piston and cylinder head valve plate
Cylinder clearance
1.00~1.50
0.50~0.75
0.80~1.20
0.50~0.85
0.40~0.90
6.1.3 The valve lift of the intake valve and exhaust valve shall comply with the provisions of Table 8. After the valve group is installed, the exhaust valve shall be tested for sealing by injecting kerosene into the valve group. Only a single drop of leakage is allowed. Table 8 Valve plate lift
Intake valve plate lift
Exhaust valve plate lift
1.6±0.15
0.45±0.1
6.1.4 After the safety valve is repaired, it should be tested for the starting pressure in the workshop and submitted for acceptance. The opening pressure difference of the safety valve is as follows:
The starting pressure difference of the safety valve of the R12 compressor is 1.05MPa; the starting pressure difference of the safety valve of the R22 compressor is 1.6MPa. 6:2 Operation test and acceptance
6.2.1 The test time of the no-load test shall not be less than 2h. After shutdown, check the heating of the friction part, and the temperature rise shall not exceed 30℃. The oil pressure shall meet the requirements of the instructions.
6.2.2 The vacuum test is carried out under the condition of 1 atmosphere of back pressure. For compressors with a cylinder diameter of no more than 70mm, the vacuum degree should be able to be drawn to less than -0.092MPa within 5 minutes. For compressors with a cylinder diameter of more than 70mm, the vacuum degree should be able to be drawn to less than -0.085MPa within 5 minutes.
6.2.3 The air pressure test is carried out under the exhaust pressure of 0.245MPa for 2h operation. After shutdown, check whether the moving parts are excessively loose and overheated. The oil temperature shall not exceed 70℃ and the oil pressure shall not fluctuate. If there are any abnormal conditions during the test, the fault shall be eliminated and the test shall be repeated until it is normal.
6.2.4 The air tightness test is carried out after the compressor is run-in, and the compressor is filled with nitrogen. The nitrogen pressure meets the following requirements: 1.05MPa for R12 compressors and 1.57MPa for R22 compressors. Then immerse the whole compressor in a clear water pool and maintain the pressure for 5 minutes. No bubbles should be emitted. You can also use the soap water leak detection method to test.
6.2.5. The compressor should be tested for air tightness, vacuum and utility operation in conjunction with the refrigeration system in accordance with the provisions of CB3378. Additional remarks:
This standard was proposed by the Ship Repair Sub-Technical Committee of the National Technical Committee for Standardization of Marine Ships. This standard is under the jurisdiction of Tianjin Ship Repair Technology Research Institute. This standard was drafted by Jiangnan Shipyard. The main drafters of this standard are Shi Huimin and Yao Rongyuan.
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