NOSHOK STANDARD NEEDLE VALVES are the work horses of the industry. The 400 Series’ metal-to-metal hard seat design is pressure rated to 10,000 psi @ 200 °F and helium leak tested to 1×10-4 ml/s for guaranteed performance and reliability. The 500 Series valves are fitted with a precision molded, replaceable Delrin® soft seat which is the key to the bubble tight seal. They have a maximum pressure rating of 6,000 psi @ 200 °F with straight through porting for bi-directional, high capacity flow and easy roddable cleaning. The all 316 stainless steel blow out proof stem provides greater service life and provides a secondary stem seal in the full open position. On the 400 Series, the stem and the one piece bonnet threads are rolled for greater strength and ease of operation. Both the 400 and 500 Series feature stem seal below the threads to protect against corrosion and galling.