Product Description

Needle Valve Product Introduction & Technical Specifications

1. Product Introduction

A needle valve is an industrial valve that precisely regulates tiny flow rates and provides reliable shut-off under high pressure differentials. It operates by rotating the stem to lift or lower the needle-shaped core, changing the annular flow area between the core and seat. Its core components include the needle core, seat, stem, and packing box.

2. Technical Specifications

 Nominal Diameter: DN5DN40 (mainstream small bore sizes); up to DN50 for special working conditions.

 Pressure Range: 0.642 MPa (6420 bar); high-pressure models up to 4134 bar.

 Temperature Range: -54C to 649C (-65 to 1200F), depending on packing and material.

 Flow Coefficient (Cv): 0.0042.4; metering valves as low as 0.004, general valves up to 2.4.

 Sealing Class: Metal hard seal meets ANSI Class VI; soft seal achieves micro-leakage performance.

 Internal Bore: 420 mm, suitable for micro flow control requirements.

 Applicable Media: Water, oil, gas, steam, acid/alkali corrosive media, high-purity liquids (e.g., photoresist).

3. Main Component Materials

 Body: Forged / Carbon steel (A105), 304/316/316L stainless steel, duplex steel (F91), Hastelloy C276, titanium alloy.Suitable for neutral media, general corrosion, severe corrosion, high-purity and harsh conditions.

 Core: 304/316L, tungsten carbide (WC), Hastelloy, ceramic.Wear-resistant, corrosion-resistant, anti-cavitation, suitable for high pressure differential and particulate media.

 Stem: 304/316L, Inconel, Monel alloy.High strength, corrosion-resistant, suitable for medium-high temperature and high pressure conditions.

 Sealing Parts: Metal-to-metal (Stellite / cobalt-based alloy), PTFE, flexible graphite, PEEK.Suitable for high temperature and high pressure, normal temperature corrosion resistance, and high-purity media.

 Packing: PTFE, flexible graphite, Grafoil.Suitable for normal temperature, medium-high temperature (648C), and high pressure differential.

4. Product Features

 Precise Regulation: 60 cone core combined with fine thread; 10 rotation results in <1% flow change, achieving micron-level opening control.

 High Pressure Sealing: Line contact / narrow-face sealing structure; metal hard seal withstands up to 4134 bar, meeting Class VI leakage requirements.

 Compact Structure: Forged body, small bore design; requires minimal installation space and is easy to maintain.

 Back Seal Protection: Back seal in full-open position protects packing from medium erosion, extending service life.

 Multi-material Adaptation: Covers carbon steel, stainless steel, special alloys and engineering plastics, suitable for all working condition media.

 High Reliability: 100,000 opening/closing cycles with zero leakage, suitable for long-term stable operation in critical process sections.

5. Classification by Working Conditions

By Pressure Rating

o Low-pressure needle valve: 1MPa (145 psi), mostly threaded / compression connection, suitable for instrument air and low-pressure water low-risk media.

o Medium-pressure needle valve: 110MPa (1451450 psi), general GU/O series, covering mainstream chemical and instrument working conditions.

o High-pressure needle valve: >10MPa (>1450 psi), combined bonnet N/HN series, withstands up to 4134 bar (60000 psi), suitable for deep-sea and oil/gas high-pressure pipelines.

By Connection Type

o Threaded connection: Internal/external thread (NPT/Metric), small bore (DN25), easy installation for instrument pipelines.

o Compression connection: Double ferrule end connection, weld-free, ideal for stainless steel instrument pipelines.

o Welded connection: Socket weld / butt weld, suitable for large bore or high-pressure working conditions with high connection strength.

o Flanged connection: Flanged end, large bore (DN>25) or frequent disassembly scenarios, suitable for finished oil transportation and urban gas pipelines.

By Functional Purpose

o Instrument needle valve: Includes 2/3/5-valve manifold, used for isolation and blowdown of pressure gauges/transmitters, quick installation with anti-leakage design.

o Regulating needle valve: With fine thread / calibrated handle, achieves 0.01 mL/min level fine flow adjustment, suitable for laboratory, sampling and air source pressure stabilization.

o Shut-off needle valve: Metal hard seal / soft seat, zero leakage shut-off, suitable for high pressure differential and hazardous media isolation.

By Flow Path Form

o Straight-through type: Linear flow path, low pressure loss, general purpose.

o Angle type: 90 flow path turn, preferred for limited installation space.

By Actuation Mode

o Manual needle valve: Handwheel / knob / lever, commonly used in laboratories and small-scale process lines.

o Pneumatic needle valve: Compressed air-driven, fast response, explosion-proof, suitable for automated production lines.

o Electric needle valve: Motor-driven, remote control, suitable for large flow and high-precision regulation.