Final answer:
Protective measures for appurtenances and connections on cylinders with a water capacity of no more than 1,000 lb include protective covers and safety devices, or secured installation to prevent damage.
Step-by-step explanation:
The question pertains to the safety measures required for the protection of connections and appurtenances attached to cylinders with a water capacity of 1,000 lb or less. These components should be safeguarded using specific means. To ensure safety, these parts might be required to have protective covers, use safety devices such as pressure-relief valves, or be installed in a way that protects them from external damage such as impacts or environmental exposure. An example of comprehensive protection could be the use of ballast tanks in a marine environment, where safety measures are taken to allow for the controlled flow-through of seawater to prevent damage or malfunctioning of the equipment due to pressure or water ingress.