This standard specifies the product classification, technical requirements, test methods, inspection rules, marking and packaging of outdoor fire hydrants. This standard applies to various outdoor fire hydrants in fire protection pipelines. GB 4452-1996 General Technical Requirements for Outdoor Fire Hydrants GB4452-1996 Standard Download Decompression Password: www.bzxz.net

National Standard of the People's Republic of China
General technical conditions for outdoor fire hydrants
General technical specification for hydrant Subject content and scope of application
GB4452—1996
Replaces GB4452.14452.3—84
This standard specifies the product classification, technical requirements, test methods, inspection rules, marking and packaging of outdoor fire hydrants. This standard applies to various outdoor fire hydrants in fire-fighting pipelines (hereinafter referred to as fire hydrants). 2 Reference standards
GB 197
GB1176
GB3265
GB6397
GB7307
Tolerances and fits of common threads (diameter 1~355mm)Metal tensile test methods
Technical conditions for cast copper alloys
Buckle-type fire-fighting joints
Metal tensile test specimens
Pipe threads without thread seals
GB9439
Grey cast iron parts
Performance requirements and test methods for fire-fighting joints
GB 12514
3 Product classification
3.1 Types and specifications
3.1.1 Fire hydrants can be divided into above-ground and underground types according to their installation occasions. 3.1.2 Fire hydrants can be divided into two types according to the connection form of their water inlet: socket type and flange type. 3.1.3 Fire hydrants can be divided into two types according to the nominal diameter of their water inlet: 100mm and 150mm. 3.1.4 For fire hydrants with a nominal diameter of 100mm for the water inlet, the water outlet of the suction pipe should use a fire interface with a specification of 100mm, and the water outlet of the water hose should use a fire interface with a specification of 65mm. 3.1.5 For fire hydrants with a nominal diameter of 150mm for the water inlet, the water outlet of the suction pipe should use a fire interface with a specification of 150mm, and the water outlet of the water hose should use a fire interface with a specification of 80mm. 3.1.6 The nominal pressure of fire hydrants can be divided into two types: 1.0MPa and 1.6MPa. Among them, the nominal pressure of the socket-type fire hydrant is 1.0MPa, and the nominal pressure of the flange-type fire hydrant is 1.6MPa.
3.2 Model compilation
3.2.1 Ground fire hydrant model:
SS000/00-00
Nominal pressure MPa
Water outlet interface specifications mm
Ground fire hydrant
Approved by the State Bureau of Technical Supervision on September 23, 1996 316
Implementation on March 1, 1997
Marking example:
GB 4452--1996
Ground fire hydrant, water outlets are 100mm and 65mm, and the nominal pressure is 1.0MPa. SS 100/65-1. 0
3.2.2 Underground fire hydrant model:
0OO/0O0-O
Nominal pressure MPa
Water outlet interface specification mm
Underground fire hydrant
Marking example:
Example 1: Underground fire hydrant, water outlets are 100mm and 65mm, and the nominal pressure is 1.0MPa. SA100/65-1.0
Example 2: Underground fire hydrant, two water outlets are 65mm, and the nominal pressure is 1.6MPa. SA 65/65-1.6
4 Technical requirements
4.1 Materials
4.1.1 Fire hydrants shall be made of gray cast iron HT200 or other metal materials with mechanical properties not lower than gray cast iron HT200. Its mechanical properties shall comply with the provisions of GB9439 or corresponding standards. 4.1.2 The valve seat and stem nut of the fire hydrant shall be made of cast copper alloy, and its performance shall comply with the provisions of GB1176. 4.1.3 The valve stem of the fire hydrant shall be made of low-carbon steel, and the surface shall be chrome-plated, or other surface treatment methods with performance not lower than chrome plating. And it shall comply with the provisions of the corresponding standards.
4.2 Appearance quality
4.2.1 The surface of the cast iron parts of the fire hydrant shall be smooth. After applying anti-rust paint, the exposed upper part shall be painted red. The color of the paint film shall be uniform, without cracks, obvious scratches and bumps.
4.2.2 The surface of the cast copper parts of the fire hydrant shall be free of serious sand holes, pores, slag holes, shrinkage, oxidation slag inclusions, cracks, cold shuts and penetration defects. 4.3 Threads
The basic dimensions and tolerances of the fire hydrant pipe threads shall comply with the provisions of GB7307. The tolerance of common threads shall comply with the requirements of 7H grade for internal threads and 8g grade for external threads in GB197. The threads shall have no missing teeth and the surface shall be smooth. 4.4 Opening height
The opening height of a fire hydrant with a nominal inlet diameter of 100mm shall be greater than 50mm, and the opening height of a fire hydrant with a nominal inlet diameter of 150mm shall be greater than 55mm.
4.5 Inlet connection dimensions
4.5.1 The flange connection dimensions shall comply with the provisions of Figure 1 and Table 1. 317
Water inlet
Nominal diameter
Flange outer diameter
Basic size
Limit deviation
4452-1996
Bolt hole center circle diameter
Basic size
Limit deviation
4.5.2 The dimensions of socket-type connection shall comply with the requirements of Figure 2, Table 2 and Table 3. Slope 1:24
Water inlet
Nominal diameter
100150
Bolt hole diameter
Basic size
Limit deviation
Number of bolts
(pcs)
Water inlet
Nominal diameter
4.6 Sealing performance
GB 44521996
Socket size
Under the nominal pressure water pressure, all connection parts and residual water discharge devices of fire hydrants shall not have leakage. 13
4.7Under 1.5 times the nominal pressure water pressure, all castings of fire hydrants shall not have leakage and damage that affects normal use. 4.8 Excess water discharge device
Fire hydrants should be equipped with an automatic excess water discharge device. When the fire hydrant is in normal use (fully open), the device must not leak.
4.9 Fire hydrant interfacebzxZ.net
4.9.1 For ground fire hydrants with a nominal water inlet diameter of 100mm, the KWS65 type external thread fixed interface specified in GB3265 shall be used. For underground fire hydrants, the KWA65 type external thread fixed interface specified in GB3265 shall be used. 4.9.2 For ground fire hydrants with a nominal water inlet diameter of 150mm, the KWS80 type external thread fixed interface specified in GB3265 shall be used. For underground fire hydrants, the KWA80 type external thread fixed interface specified in GB3265 shall be used. 4.9.3 The thread of the suction pipe interface on the fire hydrant with a nominal water inlet diameter of 100mm is M125×6, and the thread of the suction pipe interface on the fire hydrant with a nominal water inlet diameter of 150mm is M170×6. 4.9.4 The performance indicators of the fire hydrant interface shall comply with the provisions of GB12514. 5 Test methods
5.1 Materials
5.1.1 The mechanical property test of gray cast iron shall be carried out in accordance with the provisions of GB9439. The mechanical property test of other materials shall be carried out in accordance with the relevant standards. The test results shall comply with the provisions of Article 4.1.1. 5.1.2 The mechanical property test of copper castings shall be carried out in accordance with the provisions of GB228 and GB6397. The test results shall comply with the provisions of Article 4.1.2. 5.2 Inspection of appearance quality
Visual inspection. The test results shall comply with the provisions of Article 4.2. 5.3 Thread size inspection
Use thread ring gauges and plug gauges to check thread size. The accuracy of cylindrical pipe thread ring gauges and plug gauges shall not be less than grade 3. The accuracy of metric thread ring gauges and plug gauges shall not be less than grade 7g and 8H. The test results shall comply with the provisions of Article 4.3. 5.4 Opening height inspection
Rotate the valve stem from the closed state to the maximum open state, and multiply the number of rotations by the pitch of the valve stem to obtain the opening height of the fire hydrant. The test results shall comply with the provisions of Article 4.4.
5.5 Water inlet connection size inspection
Use a vernier caliper to check the connection size of the water inlet of the fire hydrant. The measuring range of the vernier caliper shall be greater than the maximum size of the sample being tested, and the accuracy of the vernier caliper shall not be less than 0.02mm. The test results shall comply with the provisions of Article 4.5. 5.6 Sealing performance test
5.6.1 During the test, water is poured in from the inlet end and the air in the sample is removed. After closing the valve, the pressure is slowly and evenly increased to the nominal pressure and the pressure is maintained for 2 minutes. The test results shall comply with the provisions of Article 4.6. 5.6.2 After the above test is completed, the water outlet is closed, the valve is opened to the maximum height, the pressure is slowly and evenly increased to the nominal pressure and the pressure is maintained for 2 minutes. The test results shall comply with the provisions of Article 4.6. 319
5.7 Water pressure strength test
GB 4452—1996
In 5.6.After the 2 tests are completed, continue to slowly and evenly increase the pressure to 1.5 times the nominal pressure and maintain the pressure for 2 minutes. The test results shall comply with the provisions of Article 4.7.
5.8 Inspection of residual water discharge device
During the test, first close the valve of the fire hydrant, then pour water from the water inlet end, and slowly open the valve to the maximum position. The test results shall comply with the provisions of Article 4.8.
5.9 Inspection of fire hydrant interface
The performance test of the fire hydrant interface shall be carried out in accordance with the provisions of GB3265 and GB12514. The test results shall comply with the provisions of Article 4.9. 5.10 Water pressure performance test device
The test device used for the performance tests of Articles 5.6, 5.7, and 5.8 shall comply with the following provisions. 5.10.1 Water pressure source: The rated working pressure of the water pressure source shall not be less than 2.5MPa. 5.10.2 Pressure display device: The lower limit of the pressure display device is 0MPa, and the upper limit is 2.5MPa to 4.0MPa. The measurement accuracy is no more than ±1.5%.
6 Inspection rules
6.1 Products must be inspected by the factory quality inspection department according to the factory inspection items before they can leave the factory. 6.2 The factory inspection shall be carried out one by one according to the provisions of Articles 4.2, 4.5, 4.6 and 4.8 of this standard, and the marks shall also be checked according to Article 7.1. 6.3 10% of the samples shall be drawn for factory inspection, and no less than 2 units shall be tested for water pressure strength. 6.4 Type inspection must be carried out in any of the following circumstances: a. When the manufacturer is trial-producing a new product, when the process, structure, or material is changed to affect the product performance; c. When the production is stopped for more than six months for re-production; when the cumulative production is 500 units; when the national quality supervision agency proposes a type inspection requirement. 6.5 Type inspection must be carried out in accordance with all items in Chapter 4 of this standard, and the number of samples shall not be less than 3 units. 6.6 Type inspection is qualified only when all the inspection results meet the requirements of this standard. 7 Marking and packaging
7.1 The model, specification, trademark or factory name of the fire hydrant should be clearly cast in a conspicuous position, and a signboard can be attached when necessary. 7.2 For products that pass the inspection, the remaining water inside the fire hydrant and the oil and dirt on the surface during the test should be removed, and anti-rust oil should be applied on the non-painted surface. When leaving the factory, the packaging should be firm and reliable. 7.3 When packaging, the product manual, packing list and product certificate should be attached. 7.4 The product packaging box must have the following information: a.
Product name:
Model specification,
Weight (net weight and gross weight);
Manufacturer name (or registered trademark),
Manufacture date.
Additional instructions:
GB4452—1996
This standard is proposed by the Ministry of Public Security of the People's Republic of China. This standard is under the jurisdiction of the Fifth Technical Committee of the National Fire Protection Standardization Technical Committee. This standard was drafted by the Shanghai Fire Science Research Institute of the Ministry of Public Security. The main drafters of this standard are Jin Yizhong, Pan Yinsu and Shen Jianmin. 321
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