This standard specifies the inspection device, inspection procedure, and interpretation of the flatness of the mechanical seal end face. This standard is applicable to the optical method using a monochromatic light source to inspect the flatness of the mechanical seal end face. JB/T 7369-1994 Mechanical seal end face flatness inspection method JB/T7369-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7369-94
Mechanical seal end face flatness
Testing method
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 seal end face flatness
Testing method
1 Subject content and scope of application
JB/T7369-94
This standard specifies the testing device, testing procedure, interpretation of flatness measurement value, etc. for mechanical seal end face flatness. This standard is applicable to the optical method using monochromatic light source to test the end face flatness of mechanical seal rings. 2 Terminology
2.1 Interference patternbZxz.net
A pattern composed of interference fringes (bright or dark bands) produced by light wave interference. 2.2 The dark band on the interference pattern of the related spectral band (light band).
3 Inspection device
3.1 The recommended inspection device structure is shown in Appendix B (reference). 3.2 The light source should be a monochromatic light source.
3.3 The optical flat crystal used for inspection should be of first-class accuracy (its flatness should be between 0.02 and 0.10μm), and the diameter of the optical flat crystal should be larger than the outer diameter of the end face of the inspected sealing ring.
3.4 ​​The device should be placed in a dry, clean workroom that avoids vibration interference. 3.5
The device should have certain protective elements to prevent the light beam from directly irradiating the observer's skin or eyes. If a reflector is used for observation, it should be ensured that the reflector is not deformed or distorted. 4 Inspection procedure
During inspection, the ambient temperature should be controlled at 20±5℃. Turn on the power switch of the flatness detector and preheat until the lamp is fully illuminated. 4.2
4.3 Remove the fibers, particles, oil stains, water vapor and other dirt on the end face of the tested sealing ring and the surface of the optical flat crystal, and make sure that the end face of the sealing ring and the surface of the optical flat crystal are not damaged.
4.4 Gently place the tested sealing ring on the optical flat crystal (or gently place the flat crystal on the sealing ring) so that the end face of the sealing ring and the optical flat crystal are in close contact. When judging the number of spectral bands, no additional external force should be applied to it. 4.5 Observe the interference pattern of the sealing end face through the mirror (or observe the interference pattern on the sealing end face through the optical flat crystal) and judge the interference spectral band.
5 Interpretation of flatness measurement value
5.1 The interpretation of flatness measurement value shall be in accordance with the provisions of Appendix A (Supplement). For the figures not included in Appendix A, the reader should refer to the legend of Appendix A for interpretation based on the correct understanding of the principle of applied light interference. 5.2 Determination of spherical convex and spherical concave surfaces
Approved by the Ministry of Machinery Industry on July 26, 1994
Implemented on July 1, 1995
JB/T7369-94
5.2.1 Observe the interference pattern from top to bottom. If the interference spectrum band moves toward the center of the circle, it is a spherical concave surface; if the interference spectrum band moves toward the outer diameter, it is a spherical convex surface.
5.2.2 Place the flat crystal on the sealing ring and gently press the outer edge of the flat crystal with your fingers. If the interference spectrum band bends along the fingers, it is a spherical convex surface; if the interference spectrum band bends outward from the fingers, it is a spherical concave surface. 5.3 The calculation formula for the measured value of flatness is: Where: 4—measured value of flatness
N number of interference spectrum bands;
λ—wavelength of monochromatic light.
The diagram of one light band is shown in Figure A1.
JB/T7369-94
Examples of common interference spectrum band diagrams
(Supplementary)
The diagram of two light bands is shown in Figure A2.
·The diagram of three light bands is shown in Figure A3.
A4The diagram of multiple light bands (> three light bands) is shown in Figure A4. JB/T7369-94
JB/T7369-94
Appendix B
Simplified schematic diagram of the structure of the recommended inspection device (reference)
Simplified schematic diagram of the structure of the recommended inspection device is shown in Figure B1. B1
D>de>d
1—Box; 2—Movable door: 3—Sealing ring; 4—Optical flat crystal; 5—Movable plate with holes; 6—Glass mirror; 7—Frosted glass, 8—Sodium light tube; 9—Voltage stabilizing element; 10—Light-shielding boardAdditional instructions:
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 of the Ministry of Machinery Industry. The main drafters of this standard are Li Xiaoou, Chang Kang, He Yujie, and Cheng Chuanqing. People's Republic of China
Mechanical Industry Standard
Flatness of Mechanical Seal End Surface
Test Method
JB/T7369-94
Published by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry Printed by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry (PO Box 8144, Beijing 100081)
Copyright reserved. No reproduction allowed
Format 880×12301/16
Sheet 1/2·Number of Words 10,000
Edition April 1995
First Printing April 1995
Print 00,001-500 Price RMB 3.00
Serial No. 94-114
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