1. Application
Thread Marine Needle Valves are installed throughout the vessel wherever precise flow adjustment, isolation, or dampening is required in small‑bore threaded piping:

• Fuel Oil Systems: Fine regulation of fuel flow to main engine and auxiliary boiler burners; pilot line flow setting; fuel recirculation control. The valve’s fine adjustment enables precise firing rate control, and lockable handles prevent tampering or vibration drift.

• Lubricating Oil & Hydraulic Systems: Precision pressure regulation, gauge isolation, and oil sampling points on main engines, gearboxes, stern tubes, and deck hydraulic power packs. Threaded connections allow direct mounting into manifolds and filter blocks.

• Steam Systems: Accurate control of steam tracing lines, gland sealing steam supply, and steam injection flow; suitable for saturated and superheated steam with appropriate packing and materials.

• Compressed Air & Instrument Air: Regulation of pneumatic supply pressure to actuators, control panels, and air tools; used as gauge snubbers to dampen pressure pulsations and protect sensitive instruments.

• Gauge & Transmitter Isolation: Direct mounting of pressure gauges, transmitters, and level instruments, providing a compact isolation valve and a dampening orifice in one threaded fitting.

• Fresh Water & Potable Water: Flow control in water treatment plants, dosing systems, and sampling lines where non‑toxic, corrosion‑resistant materials are mandatory.

2. Material Specifications
All materials are selected for proven compatibility with the intended shipboard fluid and the corrosive marine atmosphere, in accordance with applicable material standards (ASTM, EN, JIS):

• Body & Bonnet:

• Dezincification‑Resistant Brass (e.g., CW602N, CuZn36Pb2As): The economical standard for fuel, lube oil, compressed air, and freshwater services. Non‑sparking, inherently corrosion‑resistant, and requires no external coating.

• Stainless Steel AISI 316L (1.4404 / CF8M): The premium choice for aggressive fluids, high‑pressure hydraulics, steam, chemical dosing, and hygienic applications. Provides lifelong immunity to pitting and crevice corrosion.

• Duplex / Super Duplex Stainless Steel (UNS S32205 / S32750): For extreme‑pressure, warm seawater, and corrosive chemical injection services. Offers approximately twice the yield strength of 316L.

• Threads: All threaded ports — whether male or female — are precision‑machined directly into the body material or supplied as integral adaptors of the same material grade, ensuring uniform corrosion resistance and strength.

• Needle (Stem Tip) & Seat:

• Precision‑lapped from hardened stainless steel (AISI 316, 17‑4PH) for smooth throttling and metal‑to‑metal shutoff.

• Soft‑Seat Option: A replaceable insert of PTFE, PEEK, or reinforced FKM provides bubble‑tight, zero‑leakage closure (per EN 12266‑1 Rate A) for clean gases and liquids.

• Stem & Packing:

• The stem is stainless steel, with a precision‑rolled acme or metric trapezoidal thread to ensure smooth, backlash‑free adjustment and long packing life.

• Gland packing is PTFE (standard for most services) or pure graphite (for high‑temperature steam and fire‑safe applications), compressed by an adjustable gland nut. Live‑loaded packing systems are available for maintenance‑free stem sealing.

• Sealing Elements (for parallel threads):

• For female BSPP ports, bonded metal‑elastomer sealing washers (EPDM, NBR, PTFE) or O‑rings are provided.

• For male BSPP ports, a bonded seal (dowty seal) or an O‑ring in a machined groove is supplied.

3. Technical Specifications
Our Thread Marine Needle Valves are designed, manufactured, and tested in strict accordance with the following international and marine standards:

• Design & Manufacturing Standards:

• BSPP (G‑thread, parallel): ISO 228‑1.

• BSPT (R/Rc‑thread, tapered): ISO 7‑1.

• NPT: ASME B1.20.1.

• Metric: ISO 261 / DIN 13.

• General Design: Principles of ASME B16.34 (Valves – Flanged, Threaded, and Welding End) and EN 13709 (Industrial valves – Steel globe and globe stop and check valves) are applied, adapted for the compact needle valve configuration.

• Threads:

• Fire‑Safe Design (optional): API 607 / ISO 10497 certified designs with graphite packing and a metal secondary back‑seat are available for fuel oil and flammable fluid lines per SOLAS Chapter II‑2.

• Pressure Ratings:

• Standard working pressures up to 400 bar (5800 psi) for stainless steel valves in small sizes.

• Typical marine class ratings: Class 150, 300, 600, 800, 1500 (ASME B16.34); PN16 to PN400 for DIN‑based systems.

• Temperature Range:

• With PTFE packing: ‑54 °C to +230 °C.

• With graphite packing: ‑54 °C to +450 °C (subject to material pressure‑temperature derating).

• Leakage Performance:

• Metal‑seated: EN 12266‑1 Rate B or better.

• Soft‑seated: EN 12266‑1 Rate A (zero visible leakage).

• Testing & Certification:

• Every valve is hydrostatically shell‑tested at 1.5× rated pressure and seat‑tested at 1.1× rated pressure per EN 12266‑1 or API 598.

• Full EN 10204 Type 3.1 material certificates are provided for body, bonnet, stem, needle, and soft‑seat components.

• Type approval or Certificates of Conformity from all major IACS classification societies can be supplied.

4. Dimension Specifications
The threaded design provides a compact, standardized installation envelope with maximum flexibility:

• Nominal Size Range (Thread Size):

• Thread sizes from 1/8″ (DN 6) to 2″ (DN 50) , covering all standard small‑bore marine piping.

• Corresponding pipe sizes are matched to service flow and pressure requirements.

• Thread Connection Standards & Configurations:

• BSPP (G‑thread): Female (with sealing washer), Male (with bonded seal/O‑ring), or Male‑to‑Female combinations.

• BSPT (R/Rc‑thread): Male (R‑thread) tapered, Female (Rc‑thread) tapered, or combinations.

• NPT: Male tapered, Female tapered, or combinations.

• Metric: Male or female metric threads per ISO 261.

• Common configuration examples: M×M, F×F, M×F, threaded‑to‑compression fitting adaptors. The precise thread type and size (e.g., "½″ NPT M × F", "G½″ Female × G½″ Female") is permanently laser‑marked on every body.

• Body Pattern & Face‑to‑Face / Center‑to‑Face Dimensions:

• Available in Straight (in‑line) and Angle (90°) patterns.

• Compact dimensions are designed to fit standard instrument manifolds, burner fronts, and pipe galleries. For example, a typical ½″ BSPP female‑female straight needle valve has a face‑to‑face length of approximately 60–70 mm and an overall height of approximately 90–120 mm; a ½″ NPT male‑male angle valve has a center‑to‑face dimension of approximately 40–50 mm. Exact dimensional drawings are provided in the product datasheet, and the footprint is fully interchangeable with industry‑standard needle valves of the same size and thread type.

• Handle & Operation:

• Standard handle is a round knurled knob or T‑bar for finger‑tight operation.

• An optional locking nut or anti‑tamper cap prevents unauthorised adjustment or vibration drift.

• For larger sizes and higher pressures, a heavy‑duty bar handle is supplied.

• Installation Interface:

• The valve body includes a hexagon (wrenching flats) dimensioned to standard spanner sizes for tightening the threaded connections.

• For panel mounting, a bulkhead configuration with a male thread and locking nut is available on request.