Some standard content:
JB/T8097—1999
This standard is a revision of JB/T8097--95 "Measurement and evaluation method of vibration of pumps". The main technical content of the measurement method of this standard is equivalent to the international standard ISO10816-1:1995 "Mechanical vibration-measurement and evaluation of machine vibration". The evaluation method of this standard retains the content of JB/T8097-95. On non-rotating parts
For some pumps with flexible rotors, it is not completely appropriate to measure on non-rotating parts. It must be supplemented by the general principles of shaft vibration given in ISO7919-1 "Mechanical vibration of non-reciprocating machines-Measurement and evaluation criteria of rotating shafts Part 1: General principles". This standard replaces JB/T8097-95 from the date of implementation. Appendix A of this standard is a reminder appendix.
This standard is proposed and managed by the National Pump Standardization Technical Committee. The drafting unit of this standard: Shenyang Pump Research Institute. The main drafters of this standard: Wang Shimin, Gong Chuanjia. This standard was first issued in 1989 as GB10889-89 and was adjusted to JB/T8097--95 in April 1996.677
1 Scope
Mechanical Industry Standard of the People's Republic of China
Methods of measuring and evaluating vibration of pumps
Methods of measuring and evaluating vibration of pumps This standard specifies the vibration measurement and evaluation methods on the surface of non-rotating parts of pumps. JB/T 8097---1999
Replaces JB/T8097--95
This standard applies to various types of pumps and speed-regulating hydraulic couplings for pumps except submersible pumps and reciprocating pumps, with a speed generally ranging from 600 to 120001/min; less than 600r/min can be used as a reference. 2 Measurement
2.1 Measurement parameters
2.1.1 Frequency range
The vibration measurement should be broadband so as to fully cover the frequency spectrum of the pump, which is usually in the range of 10~1000Hz. 2.1.2 Vibration values
The measurement results made with instruments that meet the requirements of Chapter 3 are called vibration values at the specified measurement position and direction. When evaluating the broadband vibration of the pump, the root mean square value of the vibration velocity is usually considered based on experience because this value is related to the vibration energy. 2.1.3 Vibration severity
Measurements are usually carried out in two or three measurement directions and at each measurement position to obtain a set of different vibration values. The maximum broadband value measured under the specified pump support and operating conditions is defined as the vibration severity. 2.1.4 Measured quantities
For the purpose of this standard, the following quantities may be used: a) Vibration displacement, μm;
b) Vibration velocity, mm/s;
c) Vibration acceleration, m/s;
In general, there are no simple relationships between broadband acceleration, velocity and displacement, peak value (op), peak-to-peak value (pp), RMS value and average value of vibration. The reasons are briefly discussed in Appendix A (informative appendix). When the harmonic components of vibration are known, Appendix A specifies the exact relationships of the above quantities.
2.2 Installation and fixing of pumps
2.2.1 On-site commissioning
When acceptance tests are carried out on site, the supporting structure should be the supporting structure provided for the pump. When testing in this case, it is important to ensure that all relevant components and structures of the pump are installed. It should be noted that vibration comparisons of the same type of pump on different foundations or foundation substructures are only valid if the foundations have similar dynamic characteristics.
2.2.2 Bench Tests
For many pumps, acceptance tests are performed on a bench for economic or other reasons. The bench may have different bearing structure characteristics than those tested in the field. Such bearing structure may significantly affect the vibrations measured and every effort should be made to ensure that the natural frequency of the entire test rig is different from the rotational frequency of the pump or that no significant resonance occurs. The test rig normally meets these requirements, such as measuring vibration values in the horizontal and vertical directions on the machine base or on a pedestal near the bearing support or stator seat, which should not exceed 50% of the vibration values measured in the same direction on the bearing. In addition, the test rig should not cause any substantial change in any of the main resonant frequencies.
If significant bearing resonance is present during the acceptance test and cannot be eliminated, the vibration acceptance test must be performed on a fully installed machine on site.
2.3 Pump operating conditions
When measuring the vibration of vane pumps such as centrifugal pumps, mixed flow pumps, axial flow pumps, etc., measurements should be made at the specified speed (allowable deviation ±5%) and the allowed small flow, specified flow, and large flow. Measurements cannot be made under cavitation conditions. Vibration measurements for reduced speed tests cannot be used as a basis for evaluation.
For positive displacement pumps such as gear pumps, vane pumps, and screw pumps (except reciprocating pumps), measurements should be made under the conditions of specified speed (allowable deviation ±5%) and specified working pressure.
The hydraulic coupling should be measured at 10 speed points evenly under load, no-load and within the speed range. These 10 points are usually 100%, 90%, and *10% of the maximum speed (due to the limitation of the no-load speed range, the speed points that can be measured are allowed to be less than 10. During the load test, the rated load should be reached at the corresponding maximum speed). 2.4 Measuring points and measurement directions
Each pump has at least one or several key parts. In order to understand the vibration of the pump, we select these parts as measuring points. These measuring points should be selected where the vibration energy is transmitted to the elastic foundation or other parts of the system. The pump is usually selected at the bearing seat, base and outlet flange. The measuring points at the bearing seat and near the bearing are called the main measuring points; the measuring points at the base and outlet flange are called auxiliary measuring points. The specific position of the main measuring point of the vertical pump (labeled "1\) should be determined by trial measurement, that is, the test is conducted on the horizontal circumference of the measuring point, and the point with the maximum measured vibration value is determined as the measuring point (except Figure 8). Each measuring point must be measured for vibration in three mutually perpendicular directions (horizontal, vertical, and axial). The selection of typical pump measuring points is shown in Figures 1 to 10. For types not involved, the position of the measuring points can be determined by referring to these 10 legends.
Figure 1 is a single-stage or two-stage cantilever pump. The main measuring point is selected at the bearing seat of the suspension (or bracket), labeled "1, 2". The auxiliary measuring point is the pump foot labeled "3" (for those without pump feet, the base is selected). Figure 2 is a double-suction centrifugal pump (including various single-stage and two-stage two-end bearing centrifugal pumps). The main measuring points are selected at the bearing seats at both ends, labeled "1, 2\. The auxiliary measuring point is at the base near the side of the coupling, labeled "3". Figure 3 is a multistage centrifugal pump (including a double-shell multistage pump). The two main measuring points are on the bearing seats at both ends, numbered "1, 2", and the auxiliary measuring points are near the inlet and outlet flanges and pump feet, numbered "3". For pumps without pump feet, the auxiliary measuring points are on the base. Figure 4 is a gear pump, vane pump, and horizontal screw pump. The main measuring points are numbered "1, 2", and the auxiliary measuring points are numbered "3". Figure 5 is a hydraulic coupling. The main measuring points are selected on the input and output bearing seats, numbered "1, 2", and the auxiliary measuring points are selected at the base, numbered "3".
Figure 6 is a vertical centrifugal pump, which is divided into the following three types: a vertical multistage pump, the main measuring point is selected at the connection between the pump and the bracket, the label is "1", and the auxiliary measuring points are at the outlet flange and the foot, the labels are \2, 3";
a vertical marine centrifugal pump, the main measuring point is selected at the connection between the pump and the bracket, the label is 1", and the auxiliary measuring points are at the outlet flange and the supporting foot. The label is \2, 3"
a vertical centrifugal hanging pump, the main measuring point is "1", and the auxiliary measuring point is "2, 3". Figure 7 is a vertical mixed flow pump, a vertical axial flow pump, which is divided into the following three types: - Single-layer foundation, the main measuring point is selected at the connection between the pump base and the motor, the label is The number is "1", and the auxiliary measuring points are numbered "2, 3". A double-layer foundation, the main measuring point is selected at the height of the pump seat, numbered "1", and the auxiliary measuring points are numbered "2, 3". There is a connecting bracket between the pump seat and the motor. The main measuring point is selected at the connection between the bracket and the pump seat, numbered "1", and the auxiliary measuring points are numbered "2, 3".
Figure 8 is a vertical double-suction pump. The main measuring points are selected at the bearing seats at both ends, numbered "1, 2", and the auxiliary measuring points are numbered "3". Figure 9 is a long-axis deep well pump (including a barrel bag condensate pump). The main measuring point is on the pump seat, numbered "1", and the auxiliary measuring points are at the outlet flange and the pump seat foot, numbered "2,3".
JB/T8097--1999
Figure 10 is a vertical screw pump. The main measuring point is numbered "1" and the auxiliary measuring point is numbered "23". Figure 1
JB/T 8097--1999
JB/T 8097-1999
2.5 Environmental vibration evaluation
JB/T 8097—1999
If the measured vibration exceeds the recommended limit, it may be necessary to shut down the machine and measure the ambient vibration to ensure that it does not have a significant impact on the observed vibration. When the ambient vibration value is greater than 1/3 of the recommended limit, measures should be taken to reduce the ambient vibration value. 3 Measuring instruments
The measuring instrument should have the ability to measure the effective value of the wide-band vibration, and its frequency response range should be at least 10 to 1000 Hz. According to the vibration standard, displacement or speed or a combination of the two can be required. However, for pumps with a speed close to or lower than 600 r/min, the lower limit of the frequency response range should reach 2 Hz.
Note: If the measuring instrument is also used for diagnostic purposes, the upper frequency limit must exceed 1 000 Hz. The measurement system should be ensured to be free from environmental factors. Such as: temperature changes, magnetic field; sound field; power supply fluctuations; sensor orientation; sensor cable length. Special attention should be paid to ensure that the vibration sensor is correctly fixed and that such fixation does not reduce the measurement accuracy. 4 Pump vibration evaluation 4.1 Scale for evaluating vibration severity Vibrations with the same root mean square velocity value in the frequency range of 10 to 1000 Hz are considered to have the same vibration severity. The ratio of the two adjacent levels in Table 1 is 1:1.6. That is, the difference is 4 dB, and the difference of 4 dB represents a meaningful change in the vibration velocity of most pump vibration responses. Use the vibration severity of the pump to look up the vibration severity level range (10 to 1000 Hz) in Table 1 to determine the severity level of the pump. Table 1 Severity level Range of vibration severity>0. 07～ 0. 11
>0.11～0.18bzxZ.net
>0. 18~0. 28
>0.28~0.45
>0. 45～0. 71
>0. 71～1. 12
>1. 12~1.80
>1.80~2. 80
>2.80~4.50
>4.50~7.10
>7. 10~11. 20
>11. 20~18. 00
>18. 00~28. 00
>28.00~45. 00
4.2 Classification of pumps
JB/T 8097-1999
In order to evaluate the vibration level of the pump, the pump is divided into four categories according to the center height and speed of the pump, see Table 2. Table 2
Center height
First category
Second category
Third category
Fourth category
≤1800
>1800~4 500
>4 500～12 000
>225～550
≤1000
>1 0001 800
>1.800~4 500
>4 500~12 000
The center height of a horizontal pump is specified as the distance h (mm) from the axis of the pump to the plane on the base of the pump. >550
> 600～1 500
>1 500～3 600
>3 600~12 000
Vertical pumps do not have a center height. In order to evaluate its vibration level, a comparable size is taken as the center height of the vertical pump, that is, the projection distance between the outlet flange sealing surface of the vertical pump and the pump axis [h (mm) as shown in Figures 6 to 10] is specified as its equivalent center height. 4.3 Evaluation of the vibration level of the pump
The vibration level of the pump is divided into four levels: A, B, C, and D. Level D is unqualified. The vibration evaluation method of the pump is to first determine the type of pump according to the center height and speed of the pump by looking up Table 2, and then look up Table 3 according to the vibration severity level of the pump to obtain the vibration level of the evaluated pump.
The vibration evaluation method of the impurity pump is, for example, for a pump in the first category according to Table 2, its vibration level is evaluated by the second category in Table 3, and so on. Table 3
Range of vibration intensity
Level of vibration intensity
Boundary of vibration intensity classification, mm/s
5 Record content and format
5.1 Record content
a) Model, performance parameters, manufacturer, factory serial number of the pump; b) Measurement location, installation and fixing conditions of the pump; Category I
c) Name, model, specification, calibration unit and calibration date of the instrument used; 684
Determination of vibration level of the pump
Category II
Category III
Category IV
JB/T 8097-1999
d) Schematic diagram of measuring point locations, or indicate measuring points arranged according to Figure × in JB/T8097-1999; e) RMS value of vibration velocity at different measuring points and in different measuring directions; f) Vibration evaluated as A (or B, C, D) level according to Class X of JB/T8097-1999. 5.2 Format of vibration test report
Pump vibration test report
Product model
Measurement location
Measuring point number
Maximum flow
Specified flow
Small flow
Additional instructions
Speed, r/min
Manufacturer
Measurer
System data Dynamic measurement record
Factory code No.
Measurement date
Root mean square value of vibration velocity..4smm/s
Evaluated vibration level of pump
Center height, mm
Instruments used in measurement
Instrument name
Schematic diagram of measuring point location
Perturbation severity level
Verification unit
Evaluated vibration level
Verification date
JB/T 8097—1999
Appendix A
(Suggestive appendix)
Vibration waveform relationship
A1 The use of root mean square velocity measurement to characterize a wide range of vibration response characteristics of various types of machines has been recognized for many years and is still used in this way. For single alternating waveforms, which consist of discrete resonant components of amplitude and phase and contain no significant random vibration or shock components, various basic quantities (such as displacement, velocity, acceleration, peak value, rms value, average value, etc.) can be described by Fourier analysis using rigorous mathematical relationships. These have been derived elsewhere and are not covered in this annex. Several useful relationships are summarized below.
From the measured vibration velocity record as a function of time, the rms value of the velocity can be calculated using formula (A1): Or. ms
W(t)dt
W(t)dt
T—the sampling time, which is longer than the period of any major frequency component that makes up (t). (A1)
The values of velocity, speed and/or displacement (j=1, 2,, n respectively) for different frequencies (fi, f2,, f,) can be determined by analyzing the recorded spectrum.
If the peak-to-peak displacement value S,, S2,, S, (μm), the RMS value of velocity V,2, U (mm/s), the RMS value of acceleration (m/s2), and the frequency fi, f2, *, f (Hz) of the vibration are known, then the RMS value of the velocity characterizing the motion is given by formula (A2): Ut.ms = yuan × 10--
[(S,f)? + (S2f.)2 + ... + (Snf.)\]+++
《（)+(%)++(
Note: According to ISO2041, the frequency can also be called the periodic frequency factory. (A2)
If the vibration consists of only two significant frequency components, namely Umin and Vmax, then the RMS value of the beat frequency Ur.ms can be approximately calculated by formula (A3):
Ur. ms
（A3）
The transformation of vibration acceleration, velocity or displacement value for a single frequency resonant component can be completed by using Figure A1. If the vibration velocity of a single frequency component is known, the peak-to-peak displacement can be calculated by formula (A4): S, =
Where: S, peak-to-peak displacement value, μm;
U;--vibration velocity root mean square, mm/s. There is a component with frequency f:, frequency unit: Hz. 686
（A4)
(s)s/wu
JB/T8097—1999
Rate, Hz
Figure A1 Relationship between acceleration, velocity and displacement for a single frequency harmonic component 5000
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