Some standard content:
The People's Republic of China Construction Industry Standard Diaphragm air-pressure water supply equipment
Diaphragm air-pressure water supply equipment JG/T 3010.1—1994
Diaphragm air-pressure water supply equipment is a commonly used water supply equipment for life, production, and fire-fighting water supply systems in various civil and industrial buildings, small building complexes, residential quarters, agriculture, forestry, animal husbandry, transportation, and national defense projects. Subject content and scope of application
This standard specifies the reference standards, terminology, type parameter marking, technical requirements, test methods, inspection rules and markings, packaging, transportation, and storage of diaphragm air-pressure water supply equipment. This standard applies to diaphragm air-pressure water supply equipment (hereinafter referred to as water supply equipment) for various life (cold water, hot water) water supply, production water supply, and fire-fighting water supply systems.
Cited standards
GB 150-1989
Steel pressure vessels
GBJ16Code for fire protection design of buildings
GBJ 45
GBJ 84
GBJ 116
GB4807
Code for fire protection design of high-rise civil buildings
Code for design of automatic sprinkler fire extinguishing systems
Code for design of automatic fire alarm systems
Hygiene standard for rubber gaskets (rings) for food GB 5009.64
GB 4808
GB5749
GB5750
GB 5083
GB3287
GB3091
GB3092
GB2270
GB8163
JB1154
Analysis method of hygienic standard for rubber gaskets (rings) for food Hygienic management measures for rubber products for food
Hygienic standard for drinking water
Standard test method for drinking water
General principles for safety and sanitation design of production equipment
Technical conditions for malleable cast iron pipe connectors
Galvanized welded steel pipe for low-pressure fluid transportation
Welded steel pipe for low-pressure fluid transportation
Stainless steel seamless steel pipe
Seamless steel pipe for conveying fluid
Types and dimensions of elliptical heads
GB 1157～1160 Flanges for pressure vessels
GB 9115.1~9115.4 Flat butt welding steel pipe flange GB9119.2~9119.4 Flat plate flat welding steel pipe flange GB9123.1~9123.4 Flat steel pipe flange cover JB579
Oval rotary cover quick opening manhole
Rotary cover manhole
Rotary cover quick opening hand hole
The Ministry of Construction of the People's Republic of China approved on April 13, 1994 and implemented on December 1, 1994
JB 589
Flat cover hand hole
JB1166
Bearing support
JB1167
JB1207
Saddle support
Reinforcement ring
GB 1182~1184
Shape and position tolerances
GB 1800~1804
Tolerances and fits
Technical conditions for spring-loaded safety valves
JG/T 3010.1—1994
Industrial valve spring direct load safety valve CVA 17.2
GB 1497
Low voltage electrical, basic standards
GB4720 Electric control equipment Part 1: Low voltage electrical appliances and electric control equipment GB7251—1987 Low voltage complete switchgear GB 3047. 1
Basic dimension series for panels, racks and cabinets
Rated voltage of clearances and creepage distances for low-voltage electrical appliances for general industrial use
Rated current of electrical equipment
GB1980
Rated frequency of electrical equipment
GB2682
Colors of indicator lights and buttons in complete electrical equipment GB 4942. 2
Degree of protection of low-voltage electrical appliance enclosures
GB 998---82
Basic test methods for low-voltage electrical appliances
Determination of tensile properties of vulcanized rubber
GB3512
Test method for Shore A hardness of rubber
Test method for hot air aging of rubber
HG 4-836
Determination of flex cracking resistance of vulcanized rubber
GB 10832-1989
General technical requirements for marine centrifugal pumps and vortex pumpsGB 10889
GB 10890
GB 9969.1
JB2759
JB3084
JB2536
Vibration of pumps and measurement and evaluation methods
Noise of pumps and measurement and evaluation methods
General provisions for instructions for use of industrial products
General technical requirements for packaging of electromechanical products
Product packaging and transportation regulations for electric drive control stationsPainting, packaging and transportation of pressure vessels
Packaging storage and transportation pictorial symbols
TJ 231(—)
TJ231(Five)
Specifications for construction and acceptance of mechanical equipment installation projects (Volume 1 General Provisions)
Specifications for construction and acceptance of mechanical equipment installation projects (Volume 5 Installation of compressors, fans, pumps and air separation equipment)Specifications for construction and acceptance of industrial automation instrumentation projectsGBJ 93
GBJ242Specifications for construction and acceptance of heating and sanitary engineering projectsJB8Product labels
3 Terms
3.1 Diaphragm air pressure water supply equipment
Equipment that is usually composed of a diaphragm air pressure water tank, a water pump unit, a piping system, an electronic control system and an automatic control box (cabinet), and can automatically and continuously supply water to the water supply system whether the water pump is running or not. It has the functions of automatically starting and stopping the water pump, pressurizing water storage, stabilizing energy storage pressure, and continuously supplying water, and can prevent water quality from being polluted by the atmosphere, reduce the protective volume of the air pressure water tank, reduce the oxidation corrosion rate of the water supply system, and can operate for a long time after one gas filling.
3.2 Air pressure water tank
JG/T3010.1—1994
A type of pressure vessel. According to the principle that the product of gas pressure (P) and volume (V) is equal to a constant at a certain temperature according to Boyle's (Robert Boyle) gas law, using the extremely small compressibility of water, water can be filled into and stored in the tank by external force, and the gas is compressed and the pressure increases. When the external force disappears, the compressed gas expands and the water can be discharged. A type of internal pressure container. 3.3 Diaphragm air pressure water tank
A type of air pressure water tank. A metal or non-metal diaphragm device completely separates water and gas, so that water and gas are completely isolated.
3.4Minimum working pressure (P,)
The table pressure for starting the water pump of the control water supply equipment. Its value is equal to the pressure value of the outflow head at the most unfavorable water distribution point in the pipe network. For fire water supply equipment, it is the minimum allowable table pressure at the end of the water pump starting process. Its value is equal to the table pressure of the outflow head required by the most unfavorable fire extinguishing equipment in the pipe network.
3.5Maximum working pressure (P,)
The table pressure for stopping the water pump of the control water supply equipment. Its value is determined by the working pressure ratio (α) and the minimum working pressure (P,). For fire water supply equipment, it is the table pressure for starting the control water pump. Its value is also determined by the working pressure ratio (α) and the minimum working pressure (P).
3.6Working pressure ratio (α)
The ratio of the minimum working pressure (P, absolute pressure) to the maximum working pressure (P2 absolute pressure). 3.7 Regulated water volume (V)
refers to the difference in water volume in the pressure water tank corresponding to the maximum working pressure (P) and the minimum working pressure (P1) during the operation of the water supply equipment. That is, the maximum water volume that enters or outputs the pressure water tank each time when the working pressure ratio (α) is a constant. When used for fire water supply, it is usually called water storage volume. 3.8 Volume coefficient (β)
When calculating the total volume of the diaphragm pressure water tank, after taking into account the volume occupied by the diaphragm, an additional coefficient is added to the sum of the volume of gas and water in the tank.
3.9 Maximum working pressure (Pmax)
The maximum gauge pressure allowed to appear at the top of the diaphragm pressure water tank during normal operation. 3.10 Design pressure (P)
The pressure used to determine the thickness of the pressure water tank shell at the corresponding design temperature, that is, the design pressure of the pressure water tank marked on the nameplate. Its value shall not be less than the maximum working pressure.
3.11 Flexure cracking
Under flexure deformation, cracks appear on the surface of the specimen. 3.12 Kitchen flexing times
A physical property of the material. When the cracking procedure of the material sample is a certain level, the cumulative number of revolutions of the flexing test machine. 4 Type, basic parameters and markings
4.1 Type
The type of water supply equipment is divided according to the nature of use, diaphragm type and tank structure. 4.1.1 According to the nature of use, it is divided into:
a. Domestic and production water type;
b, fire water type.
4.1.2 According to the diaphragm type, it is divided into:
semi-diaphragm type (abbreviated as semi-diaphragm type);
full diaphragm type (abbreviated as full-diaphragm type).
According to the tank structure, it is divided into:
vertical type;
horizontal type;
ball type.
4.2 Basic parameters
4.2.1 Specification parameters
4.2.1.1 Diameter
JG/T 3010.1—1994
Vertical and horizontal diaphragm pressure water, the nominal diameter DN shall comply with the provisions of Table 1. Table 1
Spherical membrane pressure water tank, the nominal diameter DN shall comply with the provisions of Table 2. Table 2
4.2.1.3 Effective height and effective length
Vertical and horizontal diaphragm pressure water tank, the effective height H and effective length L shall comply with the provisions of Table 3. 4.2.1.4 The specifications of the inlet and outlet pipes and manholes of vertical and horizontal diaphragm pressure water tanks shall comply with the provisions of Table 4. 4.2.1.5 The specifications of the inlet and outlet pipes and manholes of spherical membrane pressure water tanks shall comply with the provisions of Table 5. Table 3
Pressure water tank
Nominal diameter
Effective height of semi-membrane vertical pressure water tank
Nominal diameter of large (hand) hole
Nominal diameter of inlet and outlet pipes
Effective height of full-membrane vertical pressure water tank
Nominal diameter of pressure water tank DN
US 400
Effective length of full-membrane horizontal pressure water tank
Nominal diameter of manhole (hand) hole
Nominal diameter of inlet and outlet pipes
4.2.1.6 Head
250250
JG/T 3010.1—1994
Nominal diameter of spherical air pressure water tank DN
10001200|1400|1600
018002000|2200240026002800|3000320034003600400
The head of the air pressure water tank shall adopt an elliptical standard push head. The size shall comply with the provisions of JB1154. 4.2.2 Performance parameters
4.2.2.1 Design pressure (P)
The design pressure of the water supply equipment refers to the design pressure P of the diaphragm air pressure water tank. The design pressure is divided into six levels:
0. 40 MPa;
0.80 MPa:
1.00 MPa;
1.20MPa;
1. 58 MPa.
4.2.2.2 Working pressure ratio α
200200
According to the nature of the use of water supply equipment, the working pressure ratio of the diaphragm pressure water tank can be in the range of 0.50~~0.90. The recommended range is 0. 65~0. 85.
4.2.3 Structural dimensions
The structural dimensions of the water supply equipment refer to the structural dimensions of the pressure water tank. 4.2.3.1 The structural dimensions of the semi-membrane vertical pressure water tank are shown in Figure 1. 4.2.3.2 The structural dimensions of the full-membrane vertical pressure water tank are shown in Figure 2. The structural dimensions of the full-membrane horizontal air pressure water tank are shown in Figure 3. 4.2.3.3
The structural dimensions of the full-membrane spherical air pressure water tank are shown in Figure 4. 4.2.3.5
In Figures 2, 3 and 4, the manholes (handholes) or water inlet and outlet pipes shown by dotted lines are positions that allow replacement. DNI
Book DN2
1-end; 2-cylinder, 3-flange; 4-inlet and outlet pipes Figure 1
1.-end; 2-simplified; 3-man (hand) hole; 4-inlet and outlet pipes Figure 2
JG/T3010.1-1994
1-end; 2-simplified, 3-man (hand) hole; 4-inlet and outlet pipes Figure 3
4.3 Model marking
4.3.1 Marking
1-spherical tank; 2-man (hand) hole, 3--inlet and outlet pipes Figure 4
4.3.1.1 The product model of water supply equipment consists of three parts, and each part is separated by a short dash (-). Rated flow
Design pressure
Nominal diameter of tank
-Tank structure type
Diaphragm type
Use nature
4.3.1.2 The first part of the model indicates the use nature, diaphragm type, tank structure and nominal diameter of the water supply equipment. It is divided into four sections:
The first section uses a Chinese pinyin letter to represent the use nature of the water supply equipment, see Table 6; the second section uses a Chinese pinyin letter to represent the diaphragm type, see Table 7: the third section uses a Chinese pinyin letter to represent the tank structure, see Table 8; the fourth section uses Arabic numerals to represent the nominal diameter of the tank, see 4.2.1. Each section should be written continuously and connected to each other.
4.3.1.3 The second part of the model indicates the design pressure of the air pressure tank of the water supply equipment. The design pressure of the tank is expressed in Arabic numerals in MPa, see 4.2.2.1.
Use
Water for life and production
Water for fire fighting
Diaphragm type
Tank structure type
Vertical air pressure tank
Horizontal air pressure water tank
Spherical air pressure water tank
JG/T3010.1—1994
4.3.1.4 The third part of the model indicates the rated (water supply) flow rate of the water supply equipment for 1 hour. The rated flow rate is expressed in Arabic numerals as m/h.
4.3.2 Marking examples
Example 1: Domestic water semi-membrane vertical water supply equipment, tank nominal diameter is 1000mm, tank design pressure is 0.60MPa, rated flow rate is 3.04m2/h:
SBL 1 000-0. 60-3. 04
Example 2: Fire water full membrane horizontal air pressure water supply equipment, tank nominal diameter is 1600mm, tank design pressure is 1.58MPa, rated flow rate is 110m2/h:
FQW 1 600-1.58-110
5 Technical requirements
5.1 General
5.1.1 Water supply equipment shall be manufactured in accordance with the drawings and technical documents approved in the prescribed procedures. 5.1.2
Water supply equipment manufacturing units must have a sound and comprehensive quality management system. It should hold a production license issued by the competent authority. 5.1.3 The manufacturer of water supply equipment for fire fighting should hold a license issued by the relevant department. 5.1.4 The manufacturer of pressure water tanks should hold a pressure vessel manufacturing license or registration certificate issued by the pressure vessel safety supervision agency. 5.1.5 The basic components of water supply equipment for life and production are shown in Figure 5. 5.1.6 The basic components of water supply equipment for fire fighting are shown in Figure 6. 5.1.7 The assembly and installation of water supply equipment should comply with the provisions of TJ231 (—) 5.1.8 The water supply equipment switchboard should comply with the provisions of GB5083. TJ231 (V).
1—Diaphragm type air pressure water tank; 2—Water pump unit; 3—Safety valve; 4—Pressure sensor; 5—Drain valve; 6—Valve; 7—Check valve; 8—Inflating port; A—Water tank (box); B—Water distribution network Figure 5
JG/T3010.1-1994
1—Diaphragm type air pressure water tank; 2—Water pump unit; 3—Safety valve; —Pressure sensor; 5.--Drain valve; 6—Electric (magnetic) valve; 7·--Water flow indicator; 8—Valve; 9．-Check valve; 8—Inflating port; A—Water tank or municipal water supply; B—Fire water supply network Figure 6
5.2 Environmental conditions
5.2.1 Water supply equipment should be able to work continuously and reliably under the following conditions. 5.2.1.1 Ambient temperature 5~40℃. bZxz.net
5.2.1.2 The relative humidity of the air shall not exceed 85% (at 20C±5℃). 5.2.2 The ambient air should be free of dust and oil mist, free of obvious corrosive gases, and well ventilated. 5.3 Performance in use
5.3.1 The water supply equipment shall be able to transport water for living, production and fire fighting at 4~70℃. 5.3.2 The water supply equipment shall be able to work normally under the condition that the water pump unit starts at 10f/h every hour. 5.3.3 When the water supply equipment is equipped with two or more water pump units and there is a spare water pump unit, the water pump unit shall be able to automatically rotate (alternate) operation.
5.3.4 The load rate of the water pump drive motor shall not be less than 40% or overloaded. 5.3.5 When used for fire water supply, the water supply equipment shall have the following functions in addition to the above performance. 5.3.5.1 The pressure water tank should have two water volumes: pressure stabilization and water storage. The pressure difference between the lower limit of the pressure stabilization water volume and the upper limit of the water storage volume should be about 0.02 MPa.
5.3.5.2 In non-fire conditions, the high-pressure water supply state of the fire water supply system should be automatically stabilized. 5.3.5.3 In the event of a fire, except for the automatic switching of the working fire water pump to the standby fire water pump due to a fault, the fire water pump should be guaranteed to operate continuously.
5.3.5.4 The fire water pump should be automatically started and should not stop automatically. It should also have the function of manually and remotely controlling the start and stop of the fire water pump. 5.4 Diaphragm pressure water tank (referred to as pressure water tank) 5.4.1 The pressure water tank belongs to the first category of pressure vessels (i.e. low-pressure vessels). 5.4.2 The design, materials, manufacturing, pressure test, inspection and acceptance of the pressure water tank shall comply with the provisions of GB150. In addition, it shall also comply with the provisions of this standard.
5.4.3 The maximum working pressure of the pressure water tank is generally determined by the following formula: Pmax 0. 95P
Where: Pmax——maximum working pressure, MPa; P—design pressure, MPa;
0.95—margin coefficient.
When the pressure water tank is equipped with a safety valve, the maximum working pressure of the pressure water tank can be equal to the design pressure. That is: Pmax =P
（1）
（2）
JG/T3010.1---1994
The regulating water volume of the pressure water tank should be determined by the following formula: V
Where: Vx
Regulating water volume (rated value), m2;
Total volume, m\;
Convergence pressure ratio;
β—volume coefficient, β1.05.
V.(l α)
The steel principle for pressure components of air pressure tanks, the use of steel plates, steel pipes, bolts and nuts shall be implemented in accordance with the provisions of Chapter 2 of GB150. When air pressure tanks are made of stainless steel, the following austenitic stainless steels shall be used: 1Cr18Ni9Ti, 0Cr19Ni9, 1Cr18Ni9. The thickness indicated on the drawing does not include the processing thinning amount. The manufacturing unit shall determine the processing thinning amount according to its own processing technology and processing capacity. However, the actual thickness of the processed product shall not be less than the nominal thickness minus the negative deviation of the steel thickness. 5.4.8
The hot and cold processing of air pressure tanks shall comply with the provisions of Article 10.2 of Chapter 10 of GB150. 5.4.9
The maximum wall thickness difference of the spherical shell after expansion and cold forming shall not be greater than 8% of the original thickness of the steel plate. That is: to - tmin ≤ 0. 08to
Where: to
Original thickness of steel plate, mm;
Minimum thickness of spherical shell, mm.
(4)
5.4.10 For spherical shells formed by expansion and pressure, the weld angle E≤5mm, and the inner and outer samples with a chord length of 250mm are used for inspection (see Figure 7). E≤12mm is allowed at the weld trisection point.
5.4.11 The inner diameter of the spherical shell formed by expansion and pressure shall not be greater than 2% of the designed inner diameter. The ovality shall not be greater than 4% of the design. 5.4.12 All edges and corners in contact with the rubber diaphragm shall be rounded. The radius of curvature of the arc r≥8mm. 5.4.13 The supports of vertical and horizontal pressure water tanks shall comply with the provisions of JB1166 and JB1167. When skirts are used, they should be manufactured and installed according to the drawings.
1 The pressure water tank should be equipped with a manhole or handhole. The dimensions of the manhole and handhole should comply with the provisions of Table 4 and Table 5, and the manufacturing and installation should comply with the provisions of 5.4.14
JB579, JB580, JB587, and JB589. The reinforcement ring should comply with the provisions of JB1207. 5.4.15 The inlet and outlet pipes of the pressure water tank should be set as one. The inlet and outlet pipes can be combined with the manhole and handhole. The position of the inlet and outlet pipes should be installed according to Figures 1, 2, 3, and 4 in 4.2.3. 5.4.16 The container flange should comply with the provisions of GB1157~~1160. 5.4.17 The tolerance of the machined parts of the pressure water tank should comply with the provisions of GB1800~1804 and GB1182~1184. The limit deviation of the tolerance size shall not be less than the 14th grade accuracy. The tolerance size of non-machined parts shall not be less than 16-level accuracy. 5.4.18 The welding of air pressure tanks shall comply with the provisions of Article 10.3 of Chapter 10 of GB150. 5.4.19 The non-destructive testing of air pressure tanks shall comply with the provisions of Article 10.8 of Chapter 10 of GB150. 551
5.4.20 Pressure test
JG/T3010.1-1994
The pressure test of the manufactured air pressure tank shall be carried out according to the requirements of the drawings, and the water pressure test is generally adopted. The water pressure test shall comply with the provisions of Articles 10.9.2 and 10.9.4 of Chapter 10 of GB150 5.4.21 The nameplate of the diaphragm air pressure tank shall comply with the provisions of GB150. Painting, packaging and transportation shall comply with the provisions of JB2536. 5.5 Rubber diaphragm
5.5.1 Type, parameters and marking
5.5.1.1 Type
According to the contact range of the rubber diaphragm with water and air in the air pressure water tank, it is divided into semi-diaphragm type and full-diaphragm type. 5.5.1.2 Basic parameters
The diameter, length, height and volume of the rubber diaphragm should match the specifications of the air pressure water tank. The dimensions that the rubber diaphragm must have are shown in Figure 8 for the semi-diaphragm type and in Figure 9 for the full-diaphragm type. (°)
5.5.1.3 Product marking
. The model number consists of two parts, separated by a short dash (-). b. The first part of the model number indicates the type, shape and outer diameter of the diaphragm. It is divided into three sections. The first section uses a Chinese phonetic letter to represent the type of diaphragm. The code is shown in Table 7. - Height or length
- Outer diameter
- Shape
Diaphragm type
The second section uses a Chinese phonetic letter to represent the shape of the diaphragm. The cap shape is M, the capsule shape is N, the sphere shape is Q, and the spherical column shape is Z. The third section uses Arabic letters to represent the outer diameter of the diaphragm, mm. The second part of the model number represents the height or length of the diaphragm. C
Use Arabic numerals to represent the height or length of the diaphragm, mm. d. Marking examples
Example 1: The type of rubber diaphragm is half-membrane, cap-shaped, inner diameter 950mm, height 300mm: BM950-300
JG/T 3010.1—1994
Example 2: The type of rubber diaphragm is full-membrane, capsule-shaped, inner diameter 1150mm, length 2150mm: QN1150-2150
Example 3: The type of rubber diaphragm is full-membrane, spherical, inner diameter 1350mm, height 2900mm: QZ1350-2900
Technical requirements
The size and wall thickness of the rubber diaphragm shall comply with the requirements of the design drawings. Material: The rubber diaphragm shall be made of food-grade rubber. It shall comply with the provisions of GB4808. Hygienic safety,
Sensory indicators
No taste, no odor, no foreign matter, uniform color. No impact on water quality. Water quality test results shall comply with the provisions of GB5749. b.
The hygienic quality of the rubber diaphragm shall comply with the provisions of GB4807. 5.5.2.4
Physical and mechanical performance indicators shall comply with the provisions of Table 9. Table 9
Hardness (Shore A type)
Tensile strength
Elongation at break
Permanent deformation at break
Flex cracking
Aging coefficient
Appearance quality shall comply with the provisions of Table 10.
Interface misalignment
5.5.2.6 Working conditions
Not allowed
Not allowed
Not allowed
Not allowed on curved surfaces
(Grade 3 cracking) 10,000 times
70℃×72h
No more than 10 other parts, each with a depth of no more than 1.5mm, and no more than 1.5mm for diameters below 5mm
The cumulative area shall not exceed 100 mm2, and the depth shall not exceed 2 mm. The temperature is 4 to 70℃;
The medium is water, nitrogen, and air.
5.5.2.7 Air tightness: The rubber diaphragm is not allowed to have air leakage. 5.5.3 Test methods
5.5.3.1 The tensile strength, elongation at break, and permanent deformation at break tests shall be carried out in accordance with the provisions of GB528. 5.5.3.2 Hardness test is carried out in accordance with the provisions of GB531. 5.5.3.3 Flex crack test is carried out in accordance with the provisions of HG4-836. 553
JG/T 3010. 1--1994
5.5.3.4 Hot air aging test is carried out in accordance with the provisions of GB3512. The aging coefficient K is calculated as follows: 2
Where: {--Tear strength of the sample before aging, MPa;.The tensile strength of the sample after aging, MPa; E-the tensile elongation of the sample before aging,%; E2\-the tensile elongation of the sample after aging,%. 5.5.3.5 Air tightness test
Fill the rubber diaphragm with air or nitrogen at a pressure of not less than 0.2MPa, and then fill it into a water tank to check for leaks or apply soapy water on the entire surface of the diaphragm for inspection. Leakage is not allowed. 5.5.3.6 Determination of the influence on water quality
Under normal room temperature conditions, take a rubber diaphragm test piece with a size (length×width×thickness) of 40mm×40mm×20mm, and immerse it in a capacity of 500mL distilled water for 24h. Determine the water sample in accordance with GB5750, and all indicators should meet the sanitary standards for drinking water. 5.5.3.7 The test method for sanitary items shall be carried out in accordance with the provisions of GB5009.64. 5.5.4 Inspection rules
5.5.4.1 The manufacturer shall designate full-time personnel to inspect the rubber diaphragms one by one in accordance with the provisions of this standard. Qualified products shall be accompanied by product quality certificates. The manufacturer shall ensure that the products shipped meet all requirements of the standard. 5.5.4.2 Physical and mechanical properties inspection shall be carried out every six months. The test results shall meet the indicators in Table 9. If any item fails to meet the indicator, double the number of samples shall be drawn for retesting the unqualified items. If one item still fails to meet the specified indicator after the retest, the batch of products shall be deemed unqualified.
5.5.4.3 The determination of the impact on water quality shall be carried out once a year. The manufacturer shall entrust the provincial capital or provincial municipal health and epidemic prevention department to conduct the inspection. If any item fails to meet the water quality indicator specified in GB5750, the batch of products shall be deemed unqualified. 5.5.4.4 Inspection of toxicity and health items: the first batch of products shall be entrusted to the provincial or provincial capital health and epidemic prevention department for inspection. Thereafter, the inspection shall be carried out every two years. If any of the physical and chemical indicators of the test results do not meet the requirements of GB4807, the product shall be deemed unqualified and shall not be put into production. 5.5.4.5 Appearance quality inspection shall be carried out one by one. Use a caliper with an accuracy of 0.02 and a magnifying glass for visual inspection. The test results shall meet the requirements of the indicators in Table 10 of Article 5.5.2.5 of this standard. If any item does not meet the indicator, it shall be deemed unqualified. 5.5.5 Marking, packaging, transportation and storage
5.5.5.1 Marking
The packaging shall be marked, including the following: a. Product name and specifications;
b. Manufacturer name;
Quantity, weight, packaging volume;
d. Date of manufacture;
"Rubber products for contact with food, keep clean". 5.5.5.2 Packaging
Each rubber diaphragm should be packed in a non-toxic plastic bag, and then packed in a woven bag or a paper (wood) board box. 5.5.5.3 Transportation
The product should be loaded in a covered carriage to avoid rain and sun exposure. It is forbidden to use iron hooks during loading and unloading to keep the product clean. 5.5.5.4 Storage
a The product should be stored in a well-ventilated warehouse with a temperature of -15-40℃ and a relative humidity of no more than 80%. b. It should not come into contact with acids, alkalis, oils and other substances harmful to rubber or human body to avoid product contamination. c. The rubber diaphragm should not be heavily pressed and should be placed more than 300mm above the ground and 1000mm away from heat sources. 5.5.5.5 Under the above storage conditions, the storage period of the rubber diaphragm is - years. 554
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