BS ISO 9803-2:2020 Vacuum technology – Mounting dimensions of pipeline fittings- Part 2: Knife-edge flange type.
1 Scope
This document specifies mounting dimensions for vacuum pipeline fittings (elbows, tees and crosses)
of knife-edge flanges for nominal bores from 16 mm to 200 mm.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3669. Vacuum technology — Dimensions of knife-edge flanges
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3669 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
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— IEC Electropedia: available at
4 Requirements
4.1 Mounting dimensions of the vacuum pipeline fittings shall be as specified in Table 1. See Figures 1 to 3.
4.2 Flange dimensions shall be as specified in ISO 3669. One or more flange should be rotatable.
BS ISO 9803-2 pdf download.