ISO 21358:2007 defines dimensions of right-angle valves that are compatible with the mounting dimensions of elbows defined in ISO 9803-1 and ISO 9803-2.
ISO 21358:2007 covers right-angle valves with flanges defined in ISO 2861-1, ISO 1609 and ISO 3669. ISO 3669 lists two flange series:
- preferred series, and
- secondary series.
ISO 21358:2007 covers only the valves with flanges of the secondary series.