Abstract: A locking device to selectively lock a regulator. The device includes a hollow member, configured to receive a handle of a regulator, where the hollow member is closed on a first end and open on a second end. The second end is configured with at least three tabs extending along a longitudinal axis of the hollow member from the second end toward the first end where any two adjacent tabs define a slot configured to receive a gas line coupled to a regulator. Each tab defines a hole near the second end that is configured for receiving a locking mechanism.