What is the purpose of the Pin-index Safety System (PISS)?

The Pin-index Safety System (PISS) is specifically designed to ensure safe and proper connections between gas cylinders and their regulators. It employs a system of pins that are uniquely configured for each type of gas, thus preventing the accidental connection of a regulator intended for one gas type to a cylinder containing a different gas.

The importance of the PISS is particularly relevant to high-pressure, small-sized cylinders, such as those used for medical gases like oxygen or nitrous oxide. These cylinders are often used in various healthcare settings, and the PISS helps mitigate the risk of incorrect gas delivery, which could lead to dangerous situations.

PISS is not applicable to transportable cylinders in a general sense or to larger oxygen tanks, where other safety mechanisms like the American National Standards Institute (ANSI) and Compressed Gas Association (CGA) connectors might be used. Additionally, while the Pin-index system does play a role in enhancing safety, it is not explicitly designed to address fire hazards, even though using different pin configurations inherently reduces the likelihood of improper gas usage, indirectly minimizing fire-related risks associated with gas mismanagement.