User guide

3-1
Section 3 Operation
Installation and Operation Manual
X-VA-8503-eng
Part Number: 541B087AHG
March, 2008
Needle Control Valves Models 8503 and 8504
3-1 Operating Precaution
3-2 General
After the NRS needle control valve has been installed in the flow line, it is
ready for operation. When the valve knob is turned counterclockwise to the
stop, the valve is fully opened. Turning the valve knob clockwise redues flow
and eventually will shut off flow. The valve is designed for fine control;
excessive tightening of the valve knob can damage the valve and reduce its
effectiveness.