Union Bonnet Needle Valve Stainless Steel

This Swagelok and FITOK structure instrumentation needle valve utilizes a robust union bonnet design, which provides exceptional mechanical sealing integrity and operator safety under high-vibration and severe thermal shock conditions. The split-body/union nut structure prevents the bonnet from accidentally backing out when the valve is fully opened under pressure. Machined from premium forged stainless steel bar stock and equipped with an ergonomic anodized aluminum or steel T-bar handle, it offers precise flow adjustment and bubble-tight metal-to-metal shut-off for downstream gauges, sampling networks, and critical process plants.

Technical Specifications

• Valve Structure: Union Bonnet Safety Design Instrumentation Needle Valve

• Body Material: 316/316L Stainless Steel (ASTM A479 bar stock / ASTM A182 forged)

• Stem Tip Design: Non-rotating hardened chrome-plated stem tip to eliminate seat galling

• Stem Packing Material: Two-piece chevron PTFE standard / Graphite for high-temperature service

• Handle Configuration: Ergonomic heavy-duty black anodized aluminum T-handle

• Inlet/Outlet End Options: Left: Double ferrule tube fitting / Right: Socket Weld (SW) ends

• Standard Tube Sizes: 1/4 inch, 3/8 inch, 1/2 inch, 6mm, 10mm, 12mm outer diameter (OD)

• Nominal Pressure Rating: 6000 psi (413 bar) at ambient temperature

• Maximum Working Temperature (PTFE): -54°C to 232°C (-65°F to 450°F)

• Maximum Working Temperature (Graphite): Up to 648°C (1200°F) severe service model

• Orifice Sizing: 0.156" (4.0mm) / 0.250" (6.4mm) depending on model configuration

• Flow Coefficient (Cv): 0.35 to 0.73 optimized for precision throttling and instrumentation isolation

• Bonnet Safety Threading: Threads are positioned above the packing to isolate them from process fluids

• Stem Threads: Cold-rolled and hardened for exceptionally smooth quarter-turn/multi-turn operation

• Safety Lock Mechanism: Union nut configuration blocks unexpected bonnet displacement under internal pressure

• Seat Design: Machined metal-to-metal integral body seat for low-torque, bubble-tight closure

• Testing Standard: 100% factory seat and shell pressure tested with pure nitrogen at 1000 psi according to BS EN 12266

• NACE Compliance: Available with material selection meeting NACE MR0175/ISO 15156 for sour gas environments

• Low Emissions Compliance: Fully tested and certified to comply with fugitive emissions under ISO 15848-1

• Traceability: Full material heat-code tracking permanently laser-marked on the valve body hex surface