NH Series Needle Valve

Features

• Pressure Rating up to 6,000 psig (413 bar) @ 100° F (38 °C ).
• Temperature Rating up to 449 °F (232°C ) with standard PTFE packing up to 1,200 °F (648°C ) with Grafoil packing.
• Standard 316 stainless steel, optional Alloy 400, and Alloy C276 construction.
• Valve stem back seating against the bevelled edge of bonnet in fully open posit ion prevents maximum leakage through bonnet when packing fails.
• 100% Factory tested

Operation Information

Curve 1 and 2 indicate the minimum actuator pressure to open or close double acting actuator against system pressure. To prolong valve life, actuators should be operated at minimum air actuator pressures. Curves shown are based on packing bolt factory adj ustment.

Packing bolt adjustment may be required to maintain the valve leak-tight. If the packing bolt is over-tightened, the actuating pressure can not overcome the friction force between the over-tightened packing and the stem. If the packing bolt is under-tightened for low system pressures, it may leak at high system pressures. However, packing bolt torque must be sufficiently maintained to prevent packing from leakage.