Stimuli are signals that trigger the senses. Receptors detect the stimuli and neurons send the signals to the brain where they're interpreted. Each sense organ includes receptors that capture relevant stimuli for transmission to the brain. The receptors in the skin are mechanoreceptors and thermoreceptors.
AWWA Butterfly valves are quick opening valves that consist of a metal circular disc or vane with its pivot axes at right angles to the direction of flow in the pipe, which when rotated on a shaft, seals against seats in the valve body. They are normally used as throttling valves to control flow.
Valves are available in a number of types, based on design and purpose: 1  Gate, plug, or ball valves â Isolation. 2  Globe valve â Throttling. 3  Needle valve â Throttling, usually with high precision but low flow. 4  Butterfly or diaphragm valves â Isolation and throttling. 5  Check valve â Preventing reverse flow (non-return)