Lecture bottles should always be returned to the distributor or manufacturer promptly when no longer needed or discarded if at atmospheric pressure. Ensure that the cylinder is properly and prominently labeled as to its contents. The cylinder valve outlet connections are designed to prevent mixing of incompatible gases. Generally, right-handed threads are used for fuel gases. Never open the cylinder valve unless the regulator is completely closed.
Regulators are specific to the gas involved.
A regulator should be attached to a cylinder without forcing the threads. If the inlet of a regulator does not fit the cylinder outlet, no effort should be made to try to force the fitting. A poor fit may indicate that the regulator is not intended for use on the gas chosen. Turn the delivery pressure adjusting screw counter-clockwise until it turns freely. This prevents unintended gas flow into the regulator.