This standard specifies the type, size, technical requirements and test methods of screw-driven hose clamps (hose clamps), which are suitable for the connection and fastening of various pipeline hoses with a pressure below 1.2 MPa. JB/T 8870-1999 Hose clamp JB/T8870-1999 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T8870-1999
Hose clamps
1999-04-05 Issued
National Machinery Industry Bureau
1999-04-05 Implementation
Mechanical Industry Standard of the People's Republic of China
Hoseclamps
JB/T8870-1999
Replaces ZBJ15001-1987
This standard specifies the type, size, technical requirements and test methods of screw-driven hose clamps (hose clamps), which are suitable for the connection and tightening of various pipeline hoses with a pressure below 1.2MPa.
The type of the hose clamp is shown in Figure 1. The specific structure is determined by the manufacturer, but the specifications and dimensions must comply with the provisions of Table 1. 62
Name and code of each parameter size
Nominal diameter of throat clamp, equal to the maximum outer diameter of the clamped hose; the sum of the length of the hoop shell and the screw head;
Thickness of steel belt;
Width of steel belt;
Width of hoop shell:
Shell height
Specification size
Specification size of throat clamp is shown in Table 1.
4 Technical requirements
The material of throat clamp shall be in accordance with the provisions of Table 2.
Approved by the State Machinery Industry Bureau on April 5, 1999 and implemented on April 5, 1999
Nominal diameter
Part name
Clamping range d
Material grade
1Cr18Ni9Ti
1Cr18Ni9Ti
1Cr18Ni9Ti
JB/T88701999
Tensile strength
≥510
373~490
≥510
373~ 490
≥510
GB69965
GB122084
GB716—83
GB1220—75
GB71665
GB1220—75
《High-quality carbon structural steel》
《Stainless steel bar》
《Ordinary carbon structural steel cold-rolled steel strip》
The screw should be designed as a right-handed single-start thread. When tightened, the throat clamp can be absolutely reliably engaged and tightened with the connected parts without any additional locking device.
The meshing of the screw and the steel strip should be kept firm. If necessary, the movable end of the steel strip can be disengaged from the meshing of the screw and can be opened to an opening equal to the maximum diameter of the hose, so that the throat clamp can be easily assembled or moved to any position for connection and tightening. 2
The screw rod shall not be out of the throat clamp housing.
JB/T8870-1999
The movable end of the steel belt shall have a tooth groove and extend to a sufficient length so that the throat clamp can work within the clamping range required by the design. To ensure the clamping effect, the limit size within the clamping range of the throat clamp shall not be selected as much as possible. 4.5
The hoop shell is not allowed to separate from the steel belt.
All parts shall be smooth and free of burrs and sharp edges. The steel belt shall be flat and not twisted. The side edges of the steel belt shall be rounded or curled. 4.7
The surface of the throat clamp shall be polished and galvanized. The minimum coating thickness is 5m. The galvanized surface shall not have defects such as flooding, pinholes, discoloration, peeling, peeling, pitting, roughness, etc. (The definition of defects is specified in the standard GB313882 "Common Terms and Terms for Electroplating"). Galvanizing should be carried out after welding and before assembly. Special surface protection shall be agreed upon by the supply and demand parties. The throat clamp shall be sampled and inspected, and the sampling method shall be agreed upon by the supply and demand parties. Each sample must be tested in accordance with the provisions of Articles 5.1, 5.2, and 5.3, and meet the specified index requirements. The test piece shall not have liquid leakage and the throat clamp shall not have any deformation. 5 Test method
Free rotation torque test
This test is intended to ensure that the lubricated throat clamp can move smoothly when it is in a free rotation state, and requires that the torque of the screw does not exceed 1.5N·m when it rotates in both the forward and reverse directions.
5.2 Torque test
5.2.1 Test conditions: The throat clamp is installed on a rigid mandrel with a mandrel diameter equal to the nominal diameter of the throat clamp. The torque test is carried out using a special torque test device.
5.2.2 Test method:
a. Tighten the hose clamp to 75% of the test value specified in Table 3, hold for 2 minutes, release the load, and visually inspect the hose clamp assembly. There should be no signs of permanent deformation or damage to the clamp shell. b. Reapply the torque until the corresponding torque test value shown in Table 3. There should still be no permanent deformation or breakage. Table 3
Clamping range
Torque test value
5.3 Pressure resistance test
Clamping ranged
5.3.1 Test conditions:
a. The ambient temperature is room temperature;
JB/T8870-1999
Continued Table 3
b. The test medium is water or hydraulic oil at room temperature; Torque test value
c. Equipped with a hose with an outer diameter equal to the middle value of the size series of the hose clamp clamping range and the corresponding test device (see Figure 2) and hydraulic device. Hydraulic joint
Annular groove
Figure 2 Test devicebzxz.net
5.3.2 Test method: Install the hose and the hose clamp on a smooth metal mandrel that matches the nominal diameter of each set of hose clamps. The torque used when tightening the hose clamps should not exceed 75% of the torque test value allowed by the corresponding hose clamps specified in Table 3. During the test, the pressure should be gradually increased from low to high, and the maximum pressure increase rate should be controlled within 105Pa/s. When the applied pressure is close to the corresponding allowable pressure test value of each set of hose clamps (see Table 4), carefully observe whether there is liquid leakage or other faults at the fitting point of the hose and the mandrel, and keep it for 1 minute, and then continue to pressurize until the allowable pressure test value of each set of hose clamps specified in Table 4 is reached, and no leakage or other faults should occur. 6
Example of marking for a hose with an outer diameter of 12mm: throat hoop d12
JB/T8870—1999
Clamping range d
Packaging, transportation and storage
Marking,
JB/T8870-1999
Pressure test value
Each throat hoop should have a permanent mark (including trademark, specification, size). The mark should be clearly embossed on the non-toothed part of the outer surface of the steel belt or on the top surface of the hoop shell.
Indicate the product name, trademark, specification, quantity, weight and manufacturer's words on the packaging carton and packaging box. After the finished product is cleaned, it is packaged in a carton. When packaging, the throat hoop mark should be in the same direction. When packaging, the protruding dimension of the active end of the steel belt extending out of the hoop shell shall not exceed 12mm. The outside of the packaging carton should be tied with plastic or nylon packaging tape. Inverting is allowed during transportation, but violent bumps and heavy drops should be avoided. Finished products should be placed in a ventilated and dry place, and should not be in direct contact with the ground or mixed with corrosive chemicals such as acids and alkalis. Additional instructions:
This standard is proposed and managed by the Standardization Research Institute. This standard was drafted by Guangzhou Machine Tool Research Institute and Tianjin Tanghuo Machinery Parts Factory. The standard number was adjusted to JB/T8870-1999 in 1999, and the technical content has not been changed. 5
People's Republic of China
Mechanical Industry Standard
JB/T8870-1999
Published and issued by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Format 880X12301/16Printing Sheet 1/2Number of Words 10.000First Edition in April 1999
Number of Printings 1-500
First Printing in April 1999
Price 10.00 Yuan
No. XX-XXX
Mechanical Industry Standard Service Network: http:/wwwJB.ac.cn66688
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