ISO 9170-1:2017 is intended especially to ensure the gas-specific assembly, mechanical resistance, flow, leakage and pressure drop of terminal units and to prevent their interchange between different gases and services and applies to terminal units: a) intended for use in medical gas pipeline systems in accordance with ISO 7396‑1; b) used as pressure outlets on pressure regulators in accordance with ISO 10524‑1; c) used as pressure outlets on pressure regulators integrated with cylinder valves (VIPR) in accordance with ISO 10524‑3. ISO 9170-1:2017 applies to terminal units for use with the following gases for administration to patients or for medical uses (A): - oxygen (A); - nitrous oxide (A); - medical air (A); - carbon dioxide (A); - oxygen/nitrous oxide mixture (A); - helium/oxygen mixtures (A); - oxygen 93 (A); - gases and gas mixtures classified as medical device (A); - gases delivered to medical devices or intended for medical purposes (A); - gases and gas mixtures for medicinal use not specified above (A). ISO 9170-1:2017 applies to terminal units for use with the following gases (B): - air for driving surgical tools (B); - nitrogen for driving surgical tools (B). This document applies to terminal units for use with vacuum systems (C). NOTE The requirements of this document can be used as guidelines for terminal units for other gases. These other gases will be considered for inclusion in this document when they come into general use. ISO 9170-1:2017 specifies requirements for terminal units for supply and disposal of nitrogen and air for driving surgical tools. ISO 9170-1:2017 specifies requirements for probes intended to be connected to the gas-specific connection point. ISO 9170-1:2017 does not specify the dimensions of probes or of the gas-specific connection points. NOTE Regional or national standards specifying dimensions of probes and gas-specific connection points are given in the Bibliography. Other connection systems in national use may be acceptable under this document. Dimensioning for such connections will be specified by their respective national standards. ISO 9170-1:2017 does not specify the requirements for terminal units for anaesthetic gas scavenging systems (AGSS), which are specified in ISO 9170‑2.