1 Scope
This part of ISO 6358 specifies a steady-state method for testing pneumatic fluid power components that
use compressible fluids, i.e. gases, and that have internal flow paths that can be
either fixed or variable in size, to determine their flow-rate characteristics. However,
this part of ISO 6358 does not apply to components whose flow coefficient is unstable during use, i.e.
components that exhibit remarkable hysteretic behaviour (because they can contain
flexible parts that deform under the flow) or that have an internal feedback phenomenon
(such as regulators). In addition, it does not apply to components that exchange energy
with the fluid during flow-rate measurement, e.g. cylinders, accumulators, etc.
Table 1 provides a summary of which parts of ISO 6358 can be applied to various components.
Table 1
—
Application of ISO 6358 test methods to components
| Components | Constant upstream pressure test |
Variable upstream pressure test |
|||
|---|---|---|---|---|---|
|
ISO 6358‑1
constant upstream pressure test |
ISO 6358‑2 charge test |
ISO 6358‑1
variable upstream pressure test |
ISO 6358‑2 discharge test | ||
| Group 1 | Directional control valves | yes | yes | yes | yes |
| Flow control valves | yes | yes | yes | yes | |
| Connectors | yes | yes | yes | yes | |
| Valve manifolds | yes | yes | yes | yes | |
| Group of components | yes | yes | yes | yes | |
| Group 2 | Filters and lubricators | yes | no | no | no |
| Non-return (check) valves | yes | no | no | no | |
| Tubes and hoses | yes | no | no | no | |
| Group 3 | Silencers and exhaust oil mist separators | no | no | yes | yes |
| Blow nozzles | no | no | yes | yes | |
| Quick-exhaust valves | no | no | yes | yes | |
| Cylinder end heads | no | no | yes | yes | |
This part of ISO 6358 specifies requirements for the test installation, the test procedure, and the presentation
of results for the steady-state method.
This part of ISO 6358 includes several test procedures, including the one described
in Annex A, which is from ISO 6358:1989. Flowmeter calibration is described in Annex B. Evaluation of measurement uncertainties is described in Annex C. Observations of the error in the test results are described in Annex D. Equations and graphical representations of flow-rate characteristics are given in
Annex E. Guidance on the use of practical units for the presentation of results is given
in Annex F. Test results using commercially available pneumatic components are given in Annex G. Guidance on calculating the flow-rate characteristics is given in Annex H. A method for evaluating the flow ability of pneumatic components using effective conductance,
Ca, is given in Annex I.