1 Scope
This document specifies a discharge test and a charge test as alternative methods
for testing pneumatic fluid power components that use compressible fluids, i.e. gases,
and that have internal flow passages that can be either fixed or variable in size
to determine their flow-rate characteristics. However, this document 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),
or components that have a cracking pressure such as non-return (check) valves and
quick-exhaust valves. In addition, it does not apply to components that exchange energy
with the fluid during flow-rate measurement, e.g. cylinders, accumulators.
NOTE This document does not provide a method to determine if a component has hysteretic behaviour; ISO 6358‑1 does provide such a method.
Table 1 provides a summary of which parts of the ISO 6358 series can be applied to various components.
Table 1
—
Application of the ISO 6358 series 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 | |
| Quick-exhaust 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 | |
| Cylinder end heads | no | no | yes | yes | |
The charge test cannot be performed on components that do not have downstream port
connections.
This document specifies requirements for the test installation, the test procedure,
and the presentation of results.
Evaluation of measurement uncertainties is described in Annex A. Requirements for a method to test the volume of an isothermal tank are given in
Annex B. Guidance on the isothermal tank is given in Annex C. Requirements for a method to test isothermal performance are given in Annex D. Guidance on the formula for calculating characteristics is given in Annex E. Guidance on calculating flow-rate characteristics is given in Annex F.