Attributes . Provide precision flow control and full shutoff in one flow direction and automatically allow unrestricted free flow in the opposite direction; Two-step needle provides fine adjustments at low flow with the first three turns of the adjusting knob. The next three turns give full-open needle position and conventional throttling control. When flow is reversed, the heavy-duty poppet/retainer permits full-flow return capacity. Exclusive color coded reference scale on the adjusting knob greatly simplifies flow setting, resetting, adjusting and return to an original flow. A simple set screw locks the valve on any desired setting. . Names