This standard replaces JB 4348-86 and JB 4345-86. JB/T 7658.12-1995 Emergency ammonia release device for ammonia refrigeration equipment JB/T7658.12-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Emergency ammonia vent for ammonia refrigeration equipment
Subject content and scope of application
JB/T 7658. 12—95
Replacement of 4345-86
JB 4348—86
This standard specifies the terminology, product classification, technical requirements, test methods, inspection rules, marking, packaging and transportation of emergency ammonia vent for ammonia refrigeration equipment (hereinafter referred to as ammonia vent). This standard applies to emergency ammonia vent for ammonia refrigeration equipment. 2 Reference standards
GB 699
GB 700
GB1300
Technical conditions for high-quality carbon structural steel
Carbon structural steel
Steel wire for welding
GB/T1804General tolerances
GB 5117
GB 8162
Carbon steel welding rods
Unindicated tolerances for linear dimensions
Seamless steel pipes for structural use
Seamless steel pipes for conveying fluids
GB 8163
GB/T13306Signages
3 Terms
3.1 Emergency ammonia releaser
In the event of an accident, the ammonia liquid in the entire refrigeration system is dissolved in water and released to prevent the refrigeration equipment from exploding and the ammonia liquid from escaping.
4 Product classification
4.1 Type
The structure of the ammonia vent is vertical.
4.2 Model
4.2.1 Model representation method
The model of the ammonia vent consists of capital Chinese phonetic letters and Arabic numerals (hereinafter referred to as numbers). The representation method of its model is as follows:
Revision number: represented by numbers, omitted for the first design product Nominal diameter of ammonia liquid pipe: represented by numbers, mm Code of ammonia vent
4.2.2 Model example
Approved by the Ministry of Machinery Industry of the People's Republic of China on June 16, 1995 1428
Implemented on July 1, 1996
JB/T 7658.12—95
JX32: represents an ammonia vent with a nominal diameter of 32mm for ammonia liquid pipe. 4.3 Basic parameters
The nominal diameter of the ammonia liquid pipe of the ammonia vent shall comply with the provisions of Table 1. Table 1
4.4 Design conditions
a. Design pressure: 2MPa;
b. Design temperature: 50℃.
5 Technical requirements
5.1 General requirements
The ammonia vent shall comply with the provisions of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures, or it may be manufactured according to the agreement between the user and the manufacturer.
5.2 Materials
The main material standards used in the ammonia vent shall comply with the provisions of Table 2. Table 2
Material name
Standard number
GB 8162, GB8163
5.2.1The body of the ammonia vent shall be made of seamless steel pipe. Steel plate
GB 699, GB 700
5.2.2 The head of the ammonia vent shall be formed by rolling of a whole piece of steel plate and shall not be spliced. 5.3 Unindicated tolerances
GB5117
GB1300
The unindicated tolerances of the linear dimensions of the cutting surface of the ammonia vent shall be in accordance with the tolerance grade m (medium grade) specified in GB/T1804, and the unindicated tolerances of the linear dimensions of the non-cutting surface shall be in accordance with the tolerance grade c (rough grade) specified in GB/T1804. 5.4 Pressure resistance and airtightness requirements
5.4.1 The ammonia vent shall be subjected to a pressure test. The hydraulic pressure test pressure shall be 1.25 times the design pressure, and the gas pressure test pressure shall be 1.15 times the design pressure. The pressure holding time shall be not less than 10 minutes, and there shall be no leakage. 5.4.2 The airtightness test can be carried out only after the hydraulic pressure test of the ammonia discharger is qualified. The test pressure is equal to the design pressure, and the pressure holding time is not less than 10 minutes. There should be no leakage. The airtightness test is not required for the ammonia discharger that has been tested and passed the air pressure test. 5.5 Cleanliness
The inside of the ammonia discharger should be clean, and the impurity content in the part in contact with the refrigerant should not exceed 800mg/m3. 5.6 Appearance qualitybzxz.net
The shape of the ammonia discharger should be beautiful and generous, and the weld surface should be free of cracks, pores, isolated pits and slag inclusions. The outer surface should be painted, and the paint should be uniform, smooth and colorful, and there should be no defects that affect the appearance. 5.7 Completeness
The ammonia discharger supplied as a set should also include:
Ammonia inlet joint;
Water inlet joint;
Discharge joint.
5.8 Accessories
5.8.1 The accessories of the ammonia releaser are:
Ammonia valve;
b. When the structure requires, an additional mounting flange can be prepared. JB/T 7658.12—95
5.8.2 The accessories of the ammonia releaser shall comply with the provisions of the relevant standards. ·5.9 Warranty period
If the user complies with the provisions of the product manual, within 18 months from the date of shipment from the manufacturer, if the ammonia releaser is damaged or fails to work properly due to poor manufacturing, the manufacturer shall replace or repair it free of charge. 6 Test method
6.1 Pressure test
6.1.1 Hydraulic pressure test
6.1.1.1 After the ammonia releaser is manufactured, a hydraulic pressure test shall be carried out. The test medium shall be clean water or other liquids that will not cause danger. The liquid temperature during the test shall be much lower than its boiling point or flash point. 6.1.1.2 The test pressure shall be in accordance with the provisions of 5.4.1. 6.1.1.3 Hydraulic pressure test method for ammonia releaser: a. Before the test, the fastening bolts of each connection part of the ammonia releaser should be fully assembled and properly tightened. The dial diameter of the test pressure gauge should be above 100mm. Two pressure gauges with the same range and calibrated and within the validity period should be used for the pressure test. The range of the pressure gauge should be about 2 times the test pressure, and should not be lower than 1.5 times and higher than 3 times the test pressure. b. During the test, an exhaust port should be set at the top of the ammonia releaser, and the air in the ammonia releaser should be exhausted when filling the liquid. The observation surface of the ammonia releaser should be kept dry during the test
Fill the inside of the ammonia releaser with the test medium, exhaust the air, and then slowly pressurize to the test pressure, and maintain the pressure for 10 minutes, and then reduce it to the design pressure. Check under the design pressure, and the ammonia releaser is qualified if there is no leakage and abnormal deformation in any part. The pressure should remain unchanged during the inspection. Continuous pressurization should not be used to maintain the test pressure unchanged, and the bolts should not be tightened under pressure. d.

After the hydraulic pressure test is completed, the liquid should be drained and dried. 6.1.2 Gas pressure test
6.1.2.1 The gas used for the gas pressure test should be dry, clean air, nitrogen or inert gas. 6.1.2.2 The gas pressure test should have safety measures, which shall be supervised and inspected by the safety department of the test unit. 6.1.2.3 The test pressure shall be in accordance with the provisions of 5.4.1. 6.1.2.4 Gas pressure test method for ammonia releaser: a. The preparation work before the test is the same as that in 6.1.1.3a. b. During the test, the pressure should be slowly increased to the test pressure, and the pressure should be maintained for 10 minutes, and then reduced to the design pressure. Under the design pressure, the various parts of the ammonia releaser are checked by soap solution or other leak detection liquid for no leakage and abnormal deformation, etc. It is qualified. If there is a leak, the pressure should be relieved and repaired, and then retested according to the above provisions.
The pressure should remain unchanged during the inspection. Continuous pressure should not be applied to maintain the test pressure unchanged. Bolts should not be tightened under pressure.
6.2 Airtightness test
6.2.1 The airtightness test should be conducted after the hydraulic pressure test is passed. If the ammonia releaser has undergone a gas pressure test, the airtightness test can be exempted. 6.2.2 The test pressure is equal to the design pressure.
6.2.3 The gas used in the airtightness test should comply with the provisions of 6.1.2.1. 6.2.4 Method for airtightness test of ammonia releaser:
The preparation work before the test is the same as that in 6.1.1.3a. a.
b. During the test, the pressure should be slowly increased to the test pressure, and after maintaining the pressure for 10 minutes, it should be placed in water not less than 5°C (or coated with foaming liquid on the outside). It is qualified if no bubbles are generated.
. If there is leakage, the hydraulic pressure test and airtightness test should be conducted again after the pressure is released and repaired. 1430
7 Inspection rules
7.1 General requirements
JB/T 7658. 12—95
The ammonia vent shall be inspected by the manufacturer's technical inspection department according to this standard and technical documents, and can only leave the factory after passing the inspection. 7.2 Inspection items
After each ammonia vent is manufactured, it shall be inspected for delivery according to the following inspection items: a.
Inspect the processing quality of the ammonia vent;
Inspect the appearance quality;
Pressure resistance and airtightness test;
Check the contents of the label;
Check the completeness of the product according to the factory documents. e.
8 Marking, packaging and transportation
8.1 Marking
8.1.1 Label
Ammonia venting device shall be equipped with a label on a clear and flat position. The label shall comply with the provisions of GB/T13306. The following contents shall be marked on the label:
Manufacturing unit and trademark;
Product model;
Product name:
Design pressure;
Design temperature;
Refrigerant;
Net weight;
Manufacturing number:
Manufacturing month.
8.1.2 Factory documents
Nitrogen venting device shall be accompanied by a product certificate when leaving the factory. 8.2 Packaging and transportation
When ammonia venting device and other refrigeration equipment are supplied as a set, they can be packed and transported together with other equipment. Before packing, the taper pipe joint shall be coated with anti-rust grease and sealed with a screw plug. The flange shall be tightened with bolts. The flange sealing surface shall be coated with anti-rust grease and sealed with a blind plate. If supplied separately, they should be properly wrapped.
Additional Notes:
This standard was proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Wuhan New World Refrigeration Industry Co., Ltd. and Dalian Refrigeration Co., Ltd. The main drafters of this standard are: Hu Zengwu, Sun Zhengguo, Ha Hongbo, Li Muzhen. This standard was first issued in January 1964 and revised for the first time in December 1986. 1431
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