1 Scope
This document specifies the requirements and procedures for impulse testing of hose, pipe and fitting assemblies for use in aerospace hydraulic systems.
This document applies to the impulse test of hose, pipe and fitting components for aerospace hydraulic systems. This document may also be used for component testing of other applicable aerospace fluid systems.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text. Where the references are dated. Only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendment sheets) applies to this document.
ISO 6771 Aerospace- Fluid systems and com- ponents- Pressure and temperature classifications
ponents- Pressure and temperature classifications)
ISO 8575 Aerospace- Fluid systems- - Hydraulic system tubing
tubing)
3 Terminology and definitions
The following terms and definitions apply to this document.
3.1 Rate of rise
Rate of rise
Defines the slope of the rise in pulse pressure (straight line section) in the pressure/time characteristic curve.
Note: The rate of rise can also be defined as the rate of change in pressure between 10% and 90% of the total rise in pulse pressure from back pressure to peak pressure.
3.2
Peak pressurepeak pressure
The maximum value of the working pressure in a short period of time.
[Source: GB/T 30206.1- 2013,2.25]
4 Test conditions.
4.1 Pulse traces
When observed on an oscilloscope, the pulse traces represent approximate pressure/time cycles. These pressure/time profiles should be within the shaded area shown in Figure 1. The dynamic pulse traces produced by the pulse test equipment should be - consistent with the pulse traces shown in Figure 1.
4.2 Calculation of lift rate
The lift rate shall be calculated according to equation (1):
n a rate of rise in kilopascals per second (kPa/s);
-peak pressure in kPa (kPa);
t2 - the time required to reach the moment 0.9p in seconds (s);
t, the time required to reach the moment of 0.1p in seconds (s).
4.3 Preparation of specimens
The preparation of the specimen should be in accordance with the relevant handling and testing requirements in the product specification.
4.4 Test fluid
The test fluid shall be the specified aerospace hydraulic system fluid or other hydraulic fluid compatible with the specimen.
5 Purpose of the test
The purpose of this test method is to determine the ability of hose, pipe and fitting assemblies to withstand hydraulic shock for qualification testing under simulated conditions.
6 Test method
To test hoses. Tube and fitting assemblies. including base or port fittings. Unless otherwise specified, peak pressures and lift rates shall be set in accordance with Table 1, peak pressures and lift rates (imperial units of measurement) are given in Table 2 and the test sequence shall be performed in accordance with Table 3.
Adjust the oscilloscope. Make sure that the peak pressure rise trace fills the oscilloscope display screen and that the pulse cycle trace is accurately recorded by photographic or other more accurate recording means, with grid lines or other markings on the photograph so that the pressure and time values at each point on the trace can be accurately checked and read. The end-to-end accuracy and sampling rate of the data acquisition system and sensor should ensure that the pulse measurement uncertainty is within the pressure waveform range of this document. The accuracy of the measurements shall be in accordance with the relevant standards.
The total number of cycles shall be 200,000 unless otherwise specified in the procurement specification.
As shown in Table 3, after the temperature has stabilised at the maximum or minimum value, a minimum holding time of 1 h is required before the start of the test sequence section. if the procurement specification requires temperature control. The fluid temperature should be measured at the test manifold. The ambient temperature test position should be approximately 150 mm from the specimen.
The peak pressure should be measured at the test manifold at the furthest end of the specimen.
7 Intended use
7.1 Standardisation
The purpose of this document is to facilitate the standardisation of impulse test requirements for hydraulic hose, pipe and fitting assemblies, standard identification and procedures and equipment for evaluating impulse tests.
7.2 Citation
If this document is cited in the specification as a requirement - part. The following additional requirements shall be specified:
a) Nominal pressure;
b) Limit working temperature;
c) specimen design.
Foreword
Introduction
1 Scope
2 Normative references
3Terms and definitions
4Test conditions
5Test purpose
6Test methods
7 Intended use
Bibliographical
Standard
GB/T 41028-2021 Requirements of aerospace fluid systems impulse testing of hydraulic hose ，tubing and fitting assemblies (English Version)
Standard No.
GB/T 41028-2021
Status
valid
Language
English
File Format
PDF
Word Count
6000 words
Price(USD)
180.0
Implemented on
2022-7-1
Delivery
via email in 1~3 business day
Detail of GB/T 41028-2021
Standard No.
GB/T 41028-2021
English Name
Requirements of aerospace fluid systems impulse testing of hydraulic hose ，tubing and fitting assemblies
1 Scope
This document specifies the requirements and procedures for impulse testing of hose, pipe and fitting assemblies for use in aerospace hydraulic systems.
This document applies to the impulse test of hose, pipe and fitting components for aerospace hydraulic systems. This document may also be used for component testing of other applicable aerospace fluid systems.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text. Where the references are dated. Only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendment sheets) applies to this document.
ISO 6771 Aerospace- Fluid systems and com- ponents- Pressure and temperature classifications
ponents- Pressure and temperature classifications)
ISO 8575 Aerospace- Fluid systems- - Hydraulic system tubing
tubing)
3 Terminology and definitions
The following terms and definitions apply to this document.
3.1 Rate of rise
Rate of rise
Defines the slope of the rise in pulse pressure (straight line section) in the pressure/time characteristic curve.
Note: The rate of rise can also be defined as the rate of change in pressure between 10% and 90% of the total rise in pulse pressure from back pressure to peak pressure.
3.2
Peak pressurepeak pressure
The maximum value of the working pressure in a short period of time.
[Source: GB/T 30206.1- 2013,2.25]
4 Test conditions.
4.1 Pulse traces
When observed on an oscilloscope, the pulse traces represent approximate pressure/time cycles. These pressure/time profiles should be within the shaded area shown in Figure 1. The dynamic pulse traces produced by the pulse test equipment should be - consistent with the pulse traces shown in Figure 1.
4.2 Calculation of lift rate
The lift rate shall be calculated according to equation (1):
n a rate of rise in kilopascals per second (kPa/s);
-peak pressure in kPa (kPa);
t2 - the time required to reach the moment 0.9p in seconds (s);
t, the time required to reach the moment of 0.1p in seconds (s).
4.3 Preparation of specimens
The preparation of the specimen should be in accordance with the relevant handling and testing requirements in the product specification.
4.4 Test fluid
The test fluid shall be the specified aerospace hydraulic system fluid or other hydraulic fluid compatible with the specimen.
5 Purpose of the test
The purpose of this test method is to determine the ability of hose, pipe and fitting assemblies to withstand hydraulic shock for qualification testing under simulated conditions.
6 Test method
To test hoses. Tube and fitting assemblies. including base or port fittings. Unless otherwise specified, peak pressures and lift rates shall be set in accordance with Table 1, peak pressures and lift rates (imperial units of measurement) are given in Table 2 and the test sequence shall be performed in accordance with Table 3.
Adjust the oscilloscope. Make sure that the peak pressure rise trace fills the oscilloscope display screen and that the pulse cycle trace is accurately recorded by photographic or other more accurate recording means, with grid lines or other markings on the photograph so that the pressure and time values at each point on the trace can be accurately checked and read. The end-to-end accuracy and sampling rate of the data acquisition system and sensor should ensure that the pulse measurement uncertainty is within the pressure waveform range of this document. The accuracy of the measurements shall be in accordance with the relevant standards.
The total number of cycles shall be 200,000 unless otherwise specified in the procurement specification.
As shown in Table 3, after the temperature has stabilised at the maximum or minimum value, a minimum holding time of 1 h is required before the start of the test sequence section. if the procurement specification requires temperature control. The fluid temperature should be measured at the test manifold. The ambient temperature test position should be approximately 150 mm from the specimen.
The peak pressure should be measured at the test manifold at the furthest end of the specimen.
7 Intended use
7.1 Standardisation
The purpose of this document is to facilitate the standardisation of impulse test requirements for hydraulic hose, pipe and fitting assemblies, standard identification and procedures and equipment for evaluating impulse tests.
7.2 Citation
If this document is cited in the specification as a requirement - part. The following additional requirements shall be specified:
a) Nominal pressure;
b) Limit working temperature;
c) specimen design.
Contents of GB/T 41028-2021
Foreword
Introduction
1 Scope
2 Normative references
3Terms and definitions
4Test conditions
5Test purpose
6Test methods
7 Intended use
Bibliographical
