Some standard content:
HG/T2289---2001
This standard is a revision of the recommended chemical industry standard HG/T22891992 "Flexible Rubber Joints" in combination with the production situation of domestic rubber joints and the use requirements of users. The main technical differences between this standard and HG/T2289-1992 are: some technical indicators have been adjusted, such as adding a structural form with a metal ring as the end face reinforcement ring of the rubber joint, refining the product classification, expanding the product specification series, correcting the angular displacement of the rubber joint, and formulating the appearance quality inspection standard of the rubber joint. Appendix A of this standard is the appendix of the standard. From the date of implementation, this standard will replace HG/T2289-1992. This standard was proposed by the Policy and Regulations Department of the former State Administration of Petroleum and Chemical Industry. This standard is under the jurisdiction of the Rubber Miscellaneous Products Branch of the National Technical Committee for Standardization of Rubber and Rubber Products. The responsible drafting unit of this standard: Sanhe Rubber Products Factory of Sanhe Ruili Rubber Products Co., Ltd. The main drafters of this standard: Wang Huifeng and Ni Jiemin. This standard was first issued on June 1, 1992. 239
1 Scope
Chemical Industry Standard of the People's Republic of China
Flexible rubber joint
Flexible rubber joint
HG/T2289-2001
Replaces HG/T2289-1992
This standard specifies the definition, classification, product marking, requirements, test methods, inspection rules and marking, packaging, storage and transportation of flexible rubber joints (hereinafter referred to as rubber joints). This standard applies to flexible connectors for metal pipes - flexible rubber joints.
2 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T528--1998 Determination of tensile stress-strain properties of vulcanized rubber and thermoplastic rubber (eqvISO37:1994) GB/T531-1999 Rubber pocket hardness test method for indentation hardness (idtISO7619:1986) GB/T532-1997 Determination of adhesion strength of vulcanized rubber and thermoplastic rubber to fabric (idtISO36:1993) Determination of low-temperature brittleness of vulcanized rubber Single specimen method GB/T 1682-1994
Test method for liquid resistance of vulcanized rubber (neqISO1817:1985) GB/T 1690-1992
GB/T3512-1983 (1989) Rubber hot air aging test method (neqISO188:1976) GB/T5563-1994 Hydraulic test method for rubber and plastic hoses and hose assemblies GB/T 5567—1994
Determination of vacuum performance of rubber, plastic hoses and hose assembliesSanitary standard for drinking water
GB/T 5749—1985
GB/T 17219—1998
Safety evaluation standard for drinking water transmission and distribution equipment and protective materialsGB/T3289.37—1982Types and dimensions of cast iron pipe connectors-Flat jointsGB/T9119.2~9119.4—1988Flat plate type flat-welded steel pipe flanges3 Definitions
This standard adopts the following definitions:
3.1 Flexible rubber joint
It consists of a rubber part reinforced with fabric and metal materials and a flange or a flat joint, and is used for shock absorption and vibration isolation, noise reduction and displacement compensation in metal piping systems.
3.2 Axial displacement
The elongation or compression of the rubber joint in the direction of fluid flow (i.e. the direction of the central axis). 3.3 Transverse displacement
The displacement of the rubber joint in the direction perpendicular to the direction of the fluid, i.e. the direction of the central axis. 3.4 Angular displacement
The sum of the angles between the vertical center lines of the two end faces of the rubber joint and the original central axis. Approved by the State Economic and Trade Commission on January 24, 2002, 240
Implemented on July 1, 2002
Classification and product marking
4.1 Classification
HG/T2289—2001
4.1.1 According to the performance, it can be divided into three categories: general, special and heat-resistant. General category: suitable for conveying water with a temperature of 15℃~80℃, acid solution or alkali solution with a concentration of less than 10%. Special category: suitable for special performance requirements, such as oil resistance, plug resistance, ozone resistance, wear resistance or chemical corrosion resistance. Heat-resistant category: suitable for conveying water with a temperature higher than 80℃. 4.1.2 According to the structural form, it can be divided into three types: single sphere, double sphere and elbow. Each form can be divided into three types: concentric same diameter, concentric different diameter and eccentric different diameter.
4.1.3 According to the connection form between the product and the pipeline, it can be divided into two types: flange connection and threaded connection. 4.1.4 According to the working pressure, it can be divided into five levels: 0.25MPa, 0.6MPa, 1.0MPa, 1.6MPa and 2.5MPa. 4.2 Product marking
4.2.1 The product should be marked in the following order: product code, type code, structure code, performance code, working pressure, nominal diameter. 4.2.2 The product and structure codes are as follows: flexible rubber joint RFJ, single sphere D, double sphere S, elbow W, concentric reducer Y., eccentric reducer Y, fan coil joint F.
4.2.3 Marking example: RFJD-1.6×200. It refers to a single sphere flexible rubber joint with a nominal diameter of 200mm and a working pressure of 1.6MPa.
5 Requirements
5.1 Product structure
Rubber joints are generally composed of inner rubber layer, fabric reinforcement layer, middle rubber layer, outer rubber layer, end reinforcement metal ring or wire ring, metal flange or parallel flexible joint. The structural form is shown in Figure 1.a and Figure 1.b. Flange or parallel flexible joint;
2--Inner and outer rubber layer;
3-Reinforcement layer;
4-Wire ring.
Figure 1.a Schematic diagram of the structure of a flexible rubber joint with a wire ring reinforced on the end face 241
5.2 Specifications and dimensions
Specifications and dimensions are shown in Table 1.
Nominal inner diameter/mm
HG/T 2289—2001
1-flange;
2-inner and outer rubber layers;
3-middle rubber layer;
4-reinforcement layer;
5-metal ring.
Figure 1.b Schematic diagram of the structure of a flexible rubber joint reinforced with a metal ring at the end face Table 1 Specifications and dimensions
Length/mm
Single sphere D
95～150
150250
Double sphere S
165～175
205～250
Elbow W
140 ~300
Fan coil joint F
165～250
Nominal inner diameter/mm
5.3Working pressure
Single sphere D
150~250
255~300
350～400
450~500
Working pressure shall comply with the provisions of Table 2.
HG/T2289--2001
Table 1 (end)
Length/mm
Double sphere S
300～350
Elbow W
140～300
Fan coil joint F
Nominal inner diameter/mm
40~150
200~350
400～1000
1 200～3 000
3 200~～4 000
80~300
50~300
100 X 80~~400 X 300
65×50~300×250
HG/T 2289-2001
Table 2 Working pressure
Working pressure/MPa
Note: The test pressure of the rubber joint is 1.5 times the working pressure, and the bursting pressure is 3 times the working pressure. Vacuum resistance
The vacuum resistance of rubber joints with a nominal inner diameter of less than 300mm and a working pressure of more than 1.6MPa shall not be less than 100kPa. The vacuum resistance of rubber joints of other specifications shall be determined by agreement between the supply and demand parties. 5.5 Displacement performance
The maximum allowable displacement of the rubber joint under the working pressure specified in Table 2 shall comply with the provisions of Table 3. Table 3 Maximum allowable displacement of rubber joints
Nominal inner diameter/mm
100~200
250~600
700~1200
1400~4000
100~150
200~350
65X50~100×65
100×80~125×80
125×100~150×100
150×125~200×125
200×150250X150
Axial elongation/mm
Axial compression/ mm
Lateral displacement/mm
Angular displacement/degree
30～20
2 or less
Nominal inner diameter/mm
250×200~~300×250
350 X 300400 X 300
40 X 32~~65X 40
65 X 50~~80 X 50
80 × 65~100 × 65
100 ×80~125×80
125×100~150×100
150×125~250×125
200×150~250×150
250×200~300×250
15 ~25
50～300
Physical and mechanical properties of rubber compounds for rubber joints 5.6
HG/T 2289-—2001
Table 3 (End)
Axial elongation/mm
Axial compression/ mm
Lateral displacement/mm
Maximum allowable displacement/mm
The physical and mechanical properties of rubber compounds for rubber joints shall comply with the requirements of Table 4. Y
Table 4 Physical and mechanical properties of rubber
Tensile strength/MPa
Elongation at break/%
Hardness (Shore A)/degree
Brittle temperature/℃
Adhesion strength (between cord layers)/(kN/m)Hot air aging
100℃X48 h
Reduction rate of tensile strength/%
Reduction rate of elongation at break/%
Mass change rate (10%HzSO,×168h×room temperature)/%Mass change rate (10%NaOH×168h×room temperature)/%Note: The specimens for the adhesion strength test are cut from the finished products with a nominal inner diameter of more than 100mm. Y
Angular displacement/degree
5.7 Safety evaluation of rubber joints for drinking water systems When rubber joints are used in drinking water systems, the water quality after passing through the product shall comply with the relevant provisions and requirements of GB/T5749 "Sanitary Standard for Drinking Water" and GB/T17219 "Safety Evaluation Standard for Drinking Water Transmission and Distribution Equipment and Protective Materials". 5.8 Appearance quality requirements for rubber parts of rubber joints See Table 5 for the appearance quality requirements for rubber parts of rubber joints. 245
Item. Table 5 Appearance quality requirements for rubber joints and rubber parts Outer rubber layer
One is allowed, with an area not exceeding 300mm2, and it can be repaired and improved at one time. Scars with a depth not exceeding 0.8mm are allowed. No more than three are allowed, and they can be repaired and improved at one time.
No depth is allowed. No more than three marks with an area not exceeding 10mm2 are allowed. They can be repaired and improved at one time.
No
No
No
No
5.9 Requirements for metal flanges and flat joints Metal flanges shall comply with the requirements of GB/T9119; flat joints shall comply with the requirements of GB/T3289.37. 5.10 Requirements when the end face of the rubber joint is reinforced with a wire ring When the end face of the rubber joint is reinforced with a wire, the wire ring should remain circular and should be located in the same plane. 6 Test methods
Appearance quality and product specifications and dimensions
Appearance quality is determined by visual inspection, and product specifications and dimensions are measured with a vernier caliper or tape measure. 6.2 Rubber physical property test
6.2.1 The tensile strength and elongation at break of the rubber shall be determined in accordance with the provisions of GB/T528. 6.2.2 The hardness of the rubber shall be determined in accordance with the provisions of GB/T531. 6.2.3 The brittle temperature test of the rubber shall be carried out in accordance with the provisions of GB/T1682. The bond strength between rubber and fabric shall be determined in accordance with the provisions of GB/T532. 6.2.4
6.2.5 The hot air aging test of the rubber shall be carried out in accordance with the provisions of GB/T3512. 6.2.6 The acid and alkali resistance test of the rubber material shall be carried out in accordance with the provisions of GB/T1690. 6.3 Finished product hydraulic and vacuum test
6.3.1 The hydraulic test shall be carried out in accordance with the provisions of 6.3 in GB/T5563. 6.3.2 The vacuum test shall be carried out in accordance with the relevant provisions of Chapters 2 to 5 in GB/T5567. 6.4 Displacement performance test
The displacement performance test shall be carried out in accordance with Appendix A.
6.5 The shape and position of the reinforcing wire ring in the end face of the rubber joint The shape and position of the reinforcing wire ring in the end face of the rubber joint shall be inspected by X-ray fluoroscopy. 6.6 Water quality inspection of water passing through the product
The water quality inspection of water passing through the product shall be carried out in accordance with the provisions of GB/T5749 and GB/T17219. Inspection rules
Product inspection classification
Inner rubber layer
Not allowed
Not allowed
Not allowed
Not allowed
Products must be inspected and approved by the quality inspection department of the manufacturer and issued with a certificate of conformity before they can leave the factory. Product inspection is divided into factory inspection and type inspection. For specific regulations, see Table 6.
Inspection items
Appearance quality
HG/T 2289 - 2001
Product inspection classification
Morphology and position of end reinforcement wire ring
Flange, flat flexible joint
Hydraulic test
Vacuum
Displacement performance
Physical properties of rubber
7.2 Type inspection
Type test should be carried out in any of the following situations. a.
Trial determination and identification of new products or old products transferred to factory production. Test method
Factory inspection
After formal production, if there are major changes in product structure, materials, and processes, which may affect product performance. During normal production, it is carried out every six months. When the product is resumed after a long period of suspension. When the factory inspection results are significantly different from the results of the previous type test. When the national quality supervision agency proposes the requirement of type test. 7.3 Product sampling inspection rules
7.3.1 Random inspection of the shape and position of the end face reinforcement wire ring
Type inspection
Random inspection shall be carried out once a month. For each random inspection, two products of one specification and one type shall be selected for X-ray fluoroscopy. If one of the test results is unqualified, two products of this type shall be selected for retest. If one product is still unqualified, the product of this type and batch shall be judged as unqualified.
7.3.2 Hydraulic test
Products with a nominal inner diameter of less than 300mm shall be sampled once a quarter; products with a nominal inner diameter of 350mm to 1000mm shall be sampled once every six months; products with a nominal inner diameter of more than 1200mm shall be sampled once a year. For each random inspection, two products of one specification and one type shall be selected for X-ray fluoroscopy. If one of the test results is unqualified, two products of this type shall be sampled for retest. If there is still one unqualified product, the product of this type and batch shall be judged as unqualified.
7.3.3 Vacuum resistance
Sampling inspection shall be conducted every six months. Two products of the product ...5 Physical properties of rubber
Aging properties are tested once a quarter, and other properties are tested once a month. Take one rubber each time and test the items specified in Table 4. If one of them fails, take another double sample for retesting the item. If one is still unqualified, the batch of rubber shall be judged as unqualified.
7.3.6 Adhesion strength
HG/T 2289—2001
Test once every six months. Take two samples from products with a nominal inner diameter of more than 100mm for testing each time. If one of the test results fails, take another two samples from the batch of products for retesting. If one is still unqualified, the batch of this type of product shall be judged as unqualified. 7.3.7 Water quality test
Test once a year under normal production conditions, but when the rubber formula changes, rubber samples should be sent for testing at any time. Each time, one rubber compound is sampled and tested according to the items specified in GB/T5749 and GB/T17219. If the test result is unqualified, two more samples should be taken from the batch of rubber compounds for retesting. If one sample is still unqualified, the batch of products is unqualified. 8 Marking, packaging, transportation, storage
8.1 Marking
The product should have a permanent mark containing at least the following contents: manufacturer name, product name, product specifications, model, working pressure. 8.2 Packaging
Packaging should be carried out according to the agreement between the supply and demand parties. The packaging should be accompanied by a valid product certificate, including the product name, product mark, production date, manufacturer name, factory address, trademark and implementation standard number. 8.3 Transportation and storage
During storage and transportation, the product should be protected from direct sunlight, rain and snow, scratches by sharp objects, and contact with acids, alkalis, oils and various organic solvents. The storage location of the product should be more than 1m away from the heat source, and the ambient temperature should be 15℃～40℃. The quality and performance of rubber joints shall meet the requirements of this standard within one year of storage from the date of production. 248
A1 Test specimen
HG/T 2289—2001
Appendix A
(Appendix to the standard)
Displacement performance test
One rubber joint that has been stored for at least 24 hours after vulcanization. A2 Test equipment
A2.1 Test bench.
A2.2 Electric pressure pump or manual pressure pump. A2.3 Pressure gauge.
A2.4 Tape measure and protractor.
A3 Test mediumbZxz.net
Water or other suitable medium
A4 Pressure increase speed
Generally controlled within the range of 0.075MPa/s to 0.175MPa/s. A5 Test preparation
Install one end of the flat rubber joint on the flat flange with the exhaust valve, and the other end on the flat flange cover with the air guide tube, connect it to the pressure test outlet pipe, and then fix it on the test bench. Start the pressure test pump, fill water or other suitable media into the rubber joint to exhaust the air, close the exhaust valve, and stop the pump. Adjust the position of the sample and fix it, measure and record the initial length of the sample. Axial displacement test
After completing the test preparation according to the steps described in A5, turn the screw of the pressure test bench to stretch or compress the rubber joint to the maximum allowable elongation or maximum allowable compression specified in Table 3, and fix the position. Increase the gauge pressure to the working pressure of the test product specified in Table 2 according to the pressure increase speed specified in A4, maintain the pressure for 5 minutes, check whether the sample has leakage, cracking or abnormal deformation, and record it. A7 Transverse displacement test
This test can be carried out alone, or it can be continued after the axial displacement test is completed and the sample is reset to the state specified in A5. Turn the screw of the pressure test table to push one end of the flexible rubber joint horizontally to the maximum allowable lateral displacement specified in Table 3 and fix the position. Increase the gauge pressure to the working pressure of the test product specified in Table 2 according to the pressure increase rate specified in A4, maintain the pressure for 5 minutes, check whether the sample has leakage, cracking or abnormal deformation and record it.
A8 Angular displacement test
This test can be carried out alone, or it can be continued after the axial displacement and lateral displacement tests are completed and the sample is reset to the state specified in A5. Turn the right-angle baffle on one side of the pressure test table to make the deflection angle of the sample end face reach the maximum angular displacement specified in Table 3. Increase the pressure to the working pressure of the test product specified in Table 2 according to the pressure increase rate specified in Table 4, maintain the pressure for 5 minutes, check whether the sample has leakage, cracking or abnormal deformation and record it.
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