DK-Lok DK-NV series high pressure needle valve in 316L stainless steel with cone-and-thread ends. The two units photographed are DK20NV-09-S, rated 20,000 psig, and DK60NV-04-S, rated 60,000 psig, both straight pattern.
Prices on request. Contact us for availability and quotations.
The DK-NV series is DK-Lok's needle valve range for medium, high and ultra-high pressure service. The stem carries a non-rotating tip, which DK-Lok credits with preventing thread galling and assuring a long life cycle, and the pattern is available straight, angle, three-way one inlet and three-way two inlets. Bodies are ASTM A276 Type 316L stainless steel, the stem is ASTM A564 Type 630 (17-4 PH), and the collar, gland and locking nut are ASTM A276 Type 304.
These valves do not use pipe thread. The connection is DK-Lok's cone-and-thread design, in which the tube end is coned and threaded and clamped by a gland and collar, and the collar type changes with the pressure class. The existing product name calls this an "Autoclave" connection - that is trade shorthand rather than DK-Lok's own term - and describes the valve as FxF, which in instrumentation usually means female NPT both ends. Neither photographed valve has an NPT port.
Both units in the photograph are straight pattern, stamped IN, FLOW with a through arrow and OUT. Decoding the DK part number: DK, then the pressure class in thousands of psig, then NV for needle valve, then the tube size in sixteenths of an inch. DK20NV-09 is therefore a 20,000 psig valve for 9/16 in tube and DK60NV-04 a 60,000 psig valve for 1/4 in tube.
When ordering, state the pressure class, the tube size, the flow pattern and the packing - PTFE is standard and graphite is offered as an option. Confirm with the branch which classes and sizes are held.
| Models Photographed | DK20NV-09-S (20,000 psig, 9/16 in tube) and DK60NV-04-S (60,000 psig, 1/4 in tube), both straight pattern |
|---|---|
| Body Material | ASTM A276 Type 316L stainless steel |
| Stem Material | ASTM A564 Type 630 (17-4 PH) stainless steel |
| Collar, Gland and Locking Nut | ASTM A276 Type 304 stainless steel |
| Packing | PTFE standard, graphite optional |
| Temperature Range | -73 to +315 °C (-100 to +600 °F) with standard PTFE packing |
| Pressure Classes (DK-NV range) | 5,500 / 7,500 / 11,000 / 11,500 / 20,000 / 30,000 / 60,000 / 100,000 / 150,000 psig; the two units photographed are the 20,000 and 60,000 psig classes |
| End Connection | Cone-and-thread; collar type varies with the pressure class |
| Flow Patterns | Straight, angle, three-way one inlet, three-way two inlets |
| Flow Coefficient (Cv) | DK20NV 0.31 at 1/4 in to 4.78 at 1 in; DK60NV 0.08 at 1/4 in to 0.14 at 9/16 in - Cv falls as the pressure class rises |
| Stem Tip | Non-rotating tip; Vee tip standard, regulating tip optional |
| Material Compliance | 316 cold-worked stainless meeting NACE MR0175, as stated by DK-Lok for its medium and high pressure fittings and valves |
