What is ISO 21358 about?
ISO 21358 discusses vacuum technology. Vacuum technology is a method used to evacuate air from a closed volume by creating a pressure differential from the closed volume to some vent, the ultimate vent being the open atmosphere. ISO 21358 defines dimensions of right-angle valves that are compatible with the mounting dimensions of elbows defined in ISO 9803-1 and ISO 9803-2. Mounting dimensions of the vacuum pipeline fittings are specified in ISO 21358.
Who is ISO 21358 for?
ISO 21358 on vacuum technology is useful for:
- Vacuum equipment manufacturers
- Design engineers
- Research and development facilities
Why should you use ISO 21358?
Vacuum technology is the most encountered method for the production, containment, and measurement of sub-atmospheric pressure. ISO 21358 discusses right-angle valves that are compatible with the mounting dimensions.
Right-angle valves also called a 90-degree ball valve are selected when you need on/off control between perpendicular pipes or connecting components. Right-angle valves are operated by a manual hand lever to turn the ball 90 degrees.
The input/output for pneumatic actuators and control solenoid for the actuators are as follows:
- Minimum pneumatic pressure (for valve open/close): 0,4 mpa
- Maximum pneumatic pressure (in order not to be destroyed): 0,7 mpa
- Thread size and unit (e.g., “mm”, “inch”) of inlet and outlet for the pneumatic actuator should be indicated on the user's manual and/or valve body (e.g., “Rc 1/4”, “1/8 NPT”)
- Electrical specification (or capacity) of contact points for open/close status indication should be indicated (e.g., “d.c. 24 V/2 A, a.c. 250 V/20 ma/50-60 Hz”)
Using ISO 21358 you can measure and test dimensions of right-angle valves that are compatible with the mounting dimensions of elbows.
What’s changed since the last update?
BS ISO 21358:2020 supersedes BS ISO 21358:2007. BS ISO 21358:2020 includes a technical change with respect to BS ISO 21358:2007:
- The normative references have been updated

