This standard specifies the type, parameters, main dimensions, model variety representation method, technical requirements, test and inspection methods, installation and use requirements of mechanical seals for alkali-resistant pumps. This standard applies to mechanical seals for alkali-resistant pumps, and its working parameters are: sealing medium pressure 0~0.5MPa; sealing medium temperature not higher than 130℃; speed not more than 3000r/min; shaft diameter 28~85mm; medium is alkaline liquid such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, calcium carbonate, potassium carbonate, etc., of which the caustic concentration is not more than 42%, and the solid phase particle content is less than 20%. JB/T 7371-1994 Mechanical seal for alkali-resistant pumps JB/T7371-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T 7371 -1994
Mechanical seals for alkali-resistant pumps
Published on July 26, 1994
Ministry of Machinery Industry of the People's Republic of China
Implementation on July 1, 1995
Mechanical Industry Standard of the People's Republic of China
Mechanical seals for alkali-resistant pumps
1 Subject content and scope of application
JB/T7371-1994
This standard specifies the type, parameters, main dimensions, model variety representation method, technical requirements, test and inspection methods, installation and use requirements of mechanical seals for alkali-resistant pumps. This standard applies to mechanical seals for alkali-resistant pumps, and its working parameters are: sealing medium pressure 0~0.5MPa; sealing medium temperature not higher than 130℃; rotation speed not greater than 3000r/min; shaft diameter 28~85mm: the medium is alkaline liquids such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, calcium carbonate, potassium carbonate, etc., among which the caustic soda concentration is not more than 42%, and the solid phase particle content is less than 20%. 2 Reference standards
GB1184
GB/T1804
GB6556
GB10444
GB/T14211
JB/T6374
ZBJ22 002
ZBJ22003||t t||ZB J22 004
ZBJ22 006
ZBJ22 017
ZBJ22 022
Tolerances of shape and position Provisions of unspecified tolerances General tolerances Unspecified tolerances of linear dimensions
Types, main dimensions, materials and identification marks of mechanical seals Methods for compiling product models of mechanical seals
Test methods of mechanical seals
Technical conditions for mechanical seals
Technical conditions for silicon carbide sealing rings for mechanical seals O-rings for mechanical seals
Carbide sealing rings for mechanical seals Cylindrical helical springs for mechanical seals
Technical conditions for acceptance of mechanical seal products
Technical conditions for carbon graphite sealing rings for mechanical seals Technical conditions for filled polytetrafluoroethylene and polytetrafluoroethylene rubber for mechanical seals 3 Types, parameters, dimensions and material codes
3.1 Type code
The basic type codes of mechanical seals for alkali-resistant pumps are 167 (I105), 168 and 169. 3.2 Working parameters and main dimensions
3.2.1167 (I105) type: double end face, multiple springs, unbalanced type, see Table 1 for structural type and working parameters, see Table 2 for main dimensions. 3.2.2168 type: external installation, single end face, single spring, polytetrafluoroethylene bellows type, see Table 3 for structural type and working parameters, see Table 4 for main dimensions.
3.2.3169 type: external installation, single end face, multiple springs, polytetrafluoroethylene bellows type, see Table 5 for structural type and working parameters, see Table 6 for main dimensions.
Approved by the Ministry of Machinery Industry on July 26, 1994
Implemented on July 1, 1995
Medium pressure p
Medium temperature
Speed ​​r/min
JB/T7371-1994
Table 1167 Mechanical Seal Type and Parameters
Double-end face, multi-spring, unbalanced type
Quality rate
≤130
Alkaline liquid, concentration <
42%, containing 10% solid particles~
Liquid sealing pressure
Liquid sealing temperature℃
≤3000
p+(0.01 ~0.02)
Water or liquid that is compatible with the medium
H8/a11
The large size of this series can reach
140mme
JB/T 7371 -1994
Main dimensions of mechanical seal
A11/h8
Medium pressure MPa
Medium temperature ℃
Speed ​​r/min
Shaft diameter mm
JB/T7371-1994
Table 3168 mechanical seal types and parameters
External, single end, single spring, polytetrafluoroethylene bellows flushing liquid
Alkaline liquid, concentration <42%, containing solid particles 10%~20%≤3000
Table Main dimensions of 4168 mechanical seal
H11/b11
Medium end
Medium pressure MPa
Medium temperature ℃
Shaft diameter mm
JB/T7371-1994
Table 5169 mechanical seal types and parameters
External, single-end face, multi-spring, polytetrafluoroethylene bellows type flushing liquid
≤130
Alkaline liquid, concentration <42%, containing solid particles 10%~20%≤3000
30 ~ 60
Main dimensions of 5169 mechanical seal
3.3 Material code
See Table 7 for common material codes.
Material for sealing ring
Tungsten carbide
Silicon carbide
Metal surface spraying
Resin impregnation graphite
Model indication method
JB/T7371-1994
Table 7 Material code
Auxiliary sealing material
Ethylene propylene rubber
Polytetrachloroethylene
Nitrile rubber
Spring and other structural parts materials
Chromium nickel steel
Chromium nickel molybdenum steel
4.1 Model indication method In addition to complying with GB In addition to the provisions of GB10444 and GB6556, the following requirements shall also be met: Spring material
Auxiliary sealing ring (including bellows) material Stationary ring material
Rotating ring material
Specifications (nominal diameter)
4.2 Marking example
a.168-38UUTF
Indicates a 168 type mechanical seal with a nominal diameter of 38mm (38), the rotating ring material is tungsten carbide (U), the stationary ring material is tungsten carbide (U), the bellows material is polytetrafluoroethylene (T), and the spring material is chrome-nickel steel (F). b.UU167-38JOEF.UBEF
indicates a 167 type mechanical seal, both the medium end and the atmosphere end are unbalanced (UU), the nominal diameter is 38mm (38), the rotating ring material on the medium side is metal surface spraying (J), the stationary ring material is silicon carbide (O), the auxiliary sealing ring material is ethylene propylene rubber (E), and the spring material is chrome-nickel steel (F). The rotating ring material on the atmosphere side is tungsten carbide (U), the stationary ring material is resin-impregnated graphite (B), the auxiliary sealing ring material is ethylene propylene rubber (E), and the spring material is chrome-nickel steel (F). 5 Technical requirements
5.1 Material requirements
5.1.1 The commonly used materials for mechanical seals for alkali-resistant pumps specified in this standard shall comply with the provisions of GB6556. The types of materials are shown in Table 7. In addition to the materials specified in the table, other materials that meet the use requirements may also be selected. 5.1.2 When the medium contains crystalline particles, the friction pair shall be made of hard materials. 5.1.3 For concentrated alkaline media, the friction pair should use nickel-based and nickel-chromium-based hard alloys. 5.1.4 Tungsten carbide, silicon carbide, and carbon graphite sealing rings should comply with the provisions of ZBJ22003, JB/T6374, and ZBJ22017 respectively. 5.1.5 The physical and mechanical properties of polytetrafluoroethylene should comply with the provisions of ZBJ22022. 5.2 Technical requirements for main parts
JB/T 7371 -1994
5.2.1 The flatness error of the sealing ring end face shall not exceed 0.0009mm; the surface roughness of the end face: hard material R, value is 3.2μm, soft material R value is 0.4μm; the surface should not have cracks, scratches, pores, looseness and other defects that affect the performance. 5.2.2 The parallelism of the sealing ring end face to the end face in contact with the auxiliary sealing ring shall comply with the 7th grade accuracy requirements of GB1184. 5.2.3 The surface roughness R of the contact area between the sealing ring and the auxiliary sealing ring is 3.2m, and the outer circle or inner hole size tolerance is h8 or H8.
5.2.4 The verticality of the end face of the stationary ring to the outer circle in contact with the auxiliary sealing ring and the verticality of the end face of the rotating ring to the inner hole in contact with the auxiliary sealing ring shall comply with the 7th grade accuracy requirements of GB1184. 5.2.5 The wall thickness tolerance of the polytetrafluoroethylene bellows is ±0.05mm5.2.6 The bevel tolerance of the matching cone surface of the sealing ring and the polytetrafluoroethylene bellows is ±15; 5.2.7 Graphite rings and polytetrafluoroethylene bellows must be subjected to static pressure tests. The test pressure is 1.25 times, for 10 minutes, there should be no cracking, leakage, etc.
5.2.8 The technical requirements of the spring shall comply with the provisions of ZBJ22004. For multi-spring mechanical seals, the free height difference between the springs in the same set of mechanical seals shall not exceed 0.5mm. 5.2.9 The technical requirements of the O-type rubber ring shall comply with the provisions of ZBJ22002. 5.2.10 The inner hole size tolerance of the spring seat is F9, and the inner hole surface roughness R. value is 3.2μm. 5.2.11 The inner hole size tolerance of the fixed section of the polytetrafluoroethylene bellows is R7, and the inner hole surface roughness R value is 3.2μm. 5.2.12 The limit deviation of the unindicated tolerance size of the parts shall comply with the f-level provisions of GB1804. 5.3 Performance requirements
5.3.1 Leakage
When the shaft diameter (or sleeve) is not greater than 50mm, it is 3mL/h; when the shaft diameter (or sleeve) is greater than 50mm, it is 5mL/h. For double-end mechanical seals, the leakage of any end face should not exceed the above value. 5.3.2 Wear
The size of the wear must meet the requirements of the service life of the mechanical seal, and the average value is not greater than 0.03mm/100h. 5.3.3 Service life
Under reasonable selection, the temperature of the sealing chamber is not greater than 80℃, and the service life is not less than 4000h under the conditions of correct use. This limit does not apply when the conditions are harsh. bzxz.net
6 Test and inspection methods
6.1 Test method
6.1.1 The mechanical seal for alkali-resistant pumps uses clean water as the test medium, and the wear of any sealing ring is not greater than 0.02mm/100h. 6.1.2 New products must be type tested in accordance with GB/T14211. 6.1.3 Before finalized products leave the factory, they shall be tested in accordance with GB/T14211. 6.2 Inspection methods
6.2.1 The flatness of the sealing end face of the sealing ring is measured by using a Class I plane crystal and monochromatic light source interference method. The surface roughness of the sealing end face of the sealing ring is checked by a roughness measuring instrument or a sample block comparison method. 6.2.2
The inspection of the wall thickness of the polytetrafluoroethylene bellows is to take one piece from each batch of products for dissection inspection. 6.2.3
6.2.4 The bevel angle of the matching cone surface of the sealing ring and the polytetrafluoroethylene bellows is inspected by a universal angle ruler with a reading value of 2".7
JB/T 7371 - 1994
The inner hole size of the polytetrafluoroethylene fixed section is measured with a plug gauge. 6.2.6 The inspections specified in other technical requirements shall be carried out in accordance with the methods specified in the relevant standards. 7
Installation and use requirements
7.1 The axial movement of the mechanical seal installation part shall not exceed 0.3mm. 7.2 When the temperature of the sealing chamber is greater than 80℃, flushing and cooling measures shall be taken as needed. 7.3 Other installation and use requirements shall be implemented in accordance with the provisions of JB4127. 8
Acceptance rules
Product acceptance should It shall be implemented in accordance with the provisions of ZBJ22006. Marking, packaging and purchase and storage
Marking, packaging and storage shall be implemented in accordance with the provisions of ZBJ22006. Additional remarks:
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Hefei General Machinery Research Institute and Dalian Acid Resistant Pump Factory. The main drafters of this standard are Zhang Yuhong, Liu Yueying, Chen Decai and Zheng Yuanshun. People's Republic of China
Mechanical Industry Standard
Mechanical Seals for Alkali Resistant Pumps
JB/T 7371 - 1994
Published by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2, Shouti South Road, Beijing
Postal Code 100044)
Format 880×1230
Printing Sheet 3/4
Word Count 16.000
First Printing in April 1995
First Edition in April 1995
Print Quantity 1-500
Price 6.00 Yuan
94 -116
Mechanical Industry Standard Service Network: http://www.JB.ac.cn6 -
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