Which type of sprinkler head has no cap or release mechanism?

• A. Pendant sprinkler head
• B. Upright sprinkler head
• C. Concealed head
• D. Deluge head

Answer: (D)

Deluge sprinkler heads are designed so that all heads are open and ready to discharge water as soon as the system is activated. There is no cap, plug, or release mechanism holding back flow at the head because water to all areas is intended to release simultaneously. The system relies on a deluge valve to open and send water through every head, so nothing at the head needs to seal it until activation. Other heads use sealing elements or cover mechanisms that require a release to expose the orifice, so they don’t fit the description of having no cap or release mechanism.