Instrument and process isolation and fine flow control · Pressure-temperature rating by material, packing temperature limits, orifice and Cv, stem tips and connections
A needle valve closes and throttles flow with a slender tapered stem tip that screws down into a small seat, so it can shut off and finely adjust flow in instrument and small process lines. Ask three things first: what pressure and temperature it must hold in which body material, which stem packing suits the temperature and fluid, and what orifice size, flow coefficient (Cv) and stem tip the flow control needs.
Manual needle valves for instrumentation and small-bore process lines, in forged or bar-stock bodies, straight or angle pattern, with threaded, tube-fitting or weld ends. Metering valves for very fine flow, bellows-sealed valves, automated control valves and large globe valves are outside this page except where compared.
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01
Hikelok's needle valve catalogue gives its NV1 forged-body series a maximum working pressure of 6,000 psig (413 bar) and a working range of −65 °F to 1,200 °F (−53 °C to 648 °C), with ratings based on ASME Class 2500. For 316 stainless steel the rating falls from 6,000 psig (413 bar) up to 100 °F to 5,160 psig (355 bar) at 200 °F, 3,760 psig (259 bar) at 600 °F and 1,715 psig (118 bar) at 1,200 °F, based on graphite stem packing. [1]
The same catalogue limits packing temperature to −65 °F to 450 °F (−53 °C to 232 °C) for PTFE, to 600 °F (315 °C) for PEEK and to 1,200 °F (648 °C) for graphite. Other series in the range are rated, for example, at 10,000 psig (689 bar) for the NV2 high-pressure valve, 3,000 psig (206 bar) and −20 °F to 450 °F for the NV7 nonrotating-stem valve and 300 psig (20.6 bar) and −20 °F to 200 °F for the NV6 toggle valve. [1]
Editorial note: the valve's working limit is the lowest of the body rating at temperature, the packing range and the end connections, so ask the supplier for the rating at your actual operating temperature, not only the headline pressure.
A single-part listing shows how far a rating drops with packing temperature. Swagelok's SS-1RS4, a 316 stainless steel integral-bonnet needle valve with a regulating stem and 1/4 in. Swagelok tube fitting ends, is rated 5,000 psig (344 bar) at 100 °F and 3,435 psig (236 bar) at its 450 °F (232 °C) maximum, with a −65 °F (−53 °C) minimum; it has a 0.172 in orifice, a maximum Cv of 0.37, a 316 stainless stem tip and is listed as low-emissions certified. Swagelok gives its O, 1, 18, 20 and 26 integral-bonnet series working pressures up to 6,000 psig (413 bar) and temperatures up to 600 °F (315 °C), with a live-loaded packing system. [4]
Editorial calculation: 3,435 ÷ 5,000 ≈ 0.69, so this valve keeps about 69% of its room-temperature rating at 450 °F; its 0.172 in (4.4 mm) orifice and Cv 0.37 sit close to the Cv 0.35 Hikelok lists for a 4.0 mm orifice, so compare quotes at the same orifice and stem type. [4] [1]
Give the supplier the fluid, design and operating pressure and temperature, required Cv or flow, orifice size, straight or angle pattern, end connections and sizes, body and seat materials, packing, stem tip (blunt, regulating, ball), panel mounting, handle, cleaning or oxygen service, and the test and certificate requirements.
02
Emerson's Control Valve Handbook defines the flow coefficient Cv as the number of US gallons per minute of 60 °F (16 °C) water that will flow through a valve with a pressure drop of 1 psi, a constant related to valve geometry at a given travel. [2]
Hikelok lists NV1 Cv values of 0.35 for a 4.0 mm (0.157 in.) orifice, 0.85 for 6.0 mm, 2.18 for 11.0 mm, 3.27 for 15.0 mm and 5.65 for 20.0 mm, with flow plotted against the number of turns open for a regulating stem. Stem tips are offered as blunt, regulating or ball types, with Stellite options; the upper and lower stem design keeps the stem threads above the packing out of the system media. [1]
Editorial calculation: applying the Cv definition to water, flow rises with the square root of pressure drop, so a fully open valve with Cv 0.35 passes about 0.35 × √100 = 3.5 US gal/min (about 13 L/min) at a 100 psi drop. Choose an orifice whose Cv covers the flow needed with margin, and a regulating tip where flow must be adjusted rather than only shut off. [2] [1]
03
FITOK's needle valve catalogue rates its NB series screwed-bonnet needle valves (cold-drawn bar body, two-piece rising non-rotating stem, back seating when fully open, panel mounting available) by body material and packing, and states that every valve is leak-tested with nitrogen or compressed air at the maximum allowable working pressure. [3]
The catalogue's pressure–temperature curves are based on graphite packing; it offers taper, regulating, ball and soft stem tips and notes that packing adjustment may be needed during service life and that valves should be stored half open. Read these ratings with the pressure-temperature basis and Cv definition above. [3] [1] [2]
Editorial calculation: choosing PTFE instead of graphite packing caps a stainless NB valve at 232 °C instead of 649 °C, and a soft PCTFE tip lowers the limit further to 93 °C.
| NB series (FITOK) | Rating |
|---|---|
| Stainless steel body | 6,000 psig (414 bar) |
| Alloy C-276 | 6,000 psig (414 bar) |
| Alloy 400 | 5,000 psig (345 bar) |
| Titanium | 3,500 psig (241 bar) |
| Brass | 3,000 psig (207 bar) |
| PTFE packing | −65 to 450 °F (−54 to 232 °C) |
| PEEK packing | −65 to 500 °F (−54 to 260 °C) |
| Graphite packing | −65 to 1,200 °F (−54 to 649 °C) |
| PCTFE soft stem tip | Limited to 200 °F (93 °C) |
| Orifices with flow curves | 0.16, 0.25, 0.39, 0.59 and 0.71 in (4.0–18.0 mm) |
State body material, maximum pressure and temperature together, the media, and the flow control needed, and ask for the pressure–temperature curve for that material and packing, the orifice size and Cv versus turns open.
04
Suppliers linked to this page list needle valves; each card links to the page reviewed.
The suppliers reviewed list instrument and industrial needle valves; ask each for the pressure-temperature table for your material, packing options, orifice sizes and Cv, stem tip types, end connections and the shell and seat test standard.
05
This is a functional reference built from the sources cited; it is not one maker's design.
| Part | Role | Fix in the order |
|---|---|---|
| Body (forged or bar stock) | Holds pressure. [1] | Material; pattern. |
| Lower stem and tip | Seals and throttles. [1] | Tip type; material. |
| Upper stem and threads | Moves the stem outside the media. [1] | Design. |
| Packing | Seals the stem. [1] | PTFE, PEEK or graphite. |
| Orifice and seat | Sets Cv. [1] [2] | Size. |
| End connections | Join the line. [1] | Type; size. |
| Handle and panel nut | Operation and mounting. [1] | Handle; panel mount. |
06
A needle valve quotation needs values for your line. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Nominal Diameter (mm) | Orifice, e.g. 4–20 mm on NV1. [1] | Orifice and end size. |
| Operating Pressure (MPa) | E.g. 413 bar (41.3 MPa) at up to 100 °F, 316 SS. [1] | Rating at your temperature. |
| Operating Temperature (°C) | Set by packing, e.g. PTFE to 232 °C, graphite to 648 °C. [1] | Range. |
| Flow Coefficient (Cv) | E.g. 0.35–5.65 on NV1. [1] [2] | Cv and curve. |
| Leakage Rate (% of rated capacity) | Seat tightness. | Test standard and result. |
| Needle Travel (mm) | Turns to open. [1] | Turns; curve. |
| Body Material | E.g. 316 SS, Alloy 400, Alloy C-276. [1] | Grade. |
| Seat Material | Metal or Stellite tip. [1] | Tip and seat. |
| Connection Type | NPT, tube fitting, socket or butt weld. [1] | Type; size. |
| Weight (kg) | Per valve. | Weight. |
| Ingress Protection | No IP rating stated in the sources reviewed. | If required. |
| Packing temperature limit | PTFE to 232 °C, PEEK to 260 °C, graphite to 649 °C in one maker's NB series. [3] | Packing and stem-tip limits. |
07
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Fluid: [type; cleanliness; oxygen or sour service] Conditions: [pressure; temperature] Flow: [Cv or flow; pressure drop] Valve: [orifice; pattern; stem tip] Materials: [body; tip; packing] Ends: [type; size] Tests: [shell; seat; certificates]
These companies list needle valves.
Lists forged, high-pressure, union-bonnet, compact, toggle and nonrotating-stem needle valves.
Product scope checked 2026-10-11
Lists screwed-bonnet and nonrotating-stem needle valves with fittings and ball valves.
Product scope checked 2026-10-11
Lists needle valves, bleed valves and other instrument valves.
Product scope checked 2026-10-11
Lists needle valves and micro flow control valves with industrial valves.
Product scope checked 2026-10-11
Lists needle valves with hydraulic and pneumatic control valves and pumps.
Product scope checked 2026-10-11
Lists needle valves with globe, gate and butterfly valves and piping.
Product scope checked 2026-10-11
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The packing as well as the body rating; Hikelok limits PTFE to 450 °F (232 °C), PEEK to 600 °F (315 °C) and graphite to 1,200 °F (648 °C). [1]
The US gallons per minute of 60 °F water that flow with a 1 psi pressure drop (Emerson). [2]
No; Hikelok's 316 SS NV1 falls from 6,000 psig at 100 °F to 1,715 psig at 1,200 °F. [1]
FITOK's NB series catalogue gives PTFE packing −54 to 232 °C, PEEK to 260 °C and graphite to 649 °C, with soft PCTFE tips limited to 93 °C. [3]
It depends on body and packing; Swagelok's SS-1RS4 is rated 5,000 psig at 100 °F and 3,435 psig at its 450 °F maximum, about 69% of the room-temperature rating (editorial calculation). [4]
Sources checked 2026-10-12. Hikelok, FITOK and Swagelok describe their own valves; Emerson's handbook is a maker's engineering reference for valve sizing terms. Ratings for another valve must come from its own pressure-temperature table.
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