Specification

Flange Loose Gear Cryogenic Bevel Gear Operated Flat Cast Steel Gate Valves

I. Product Overview

NEWWAY flanged bevel gear cryogenic gate valves are engineered for low-temperature applications, featuring cast steel (WCB/LCB) bodies and bevel gear drives. With extended stems and thermal insulation, they resist cryogenic media erosion. Covering DN50-DN600 and PN16-PN40, these valves operate stably at -46°C to 150°C, ideal for LNG, liquid nitrogen, and oxygen cutoff control. Their bidirectional sealing meets API 6D, while bevel gear drives reduce operation torque by 70%, suitable for petrochemical, air separation, and cryogenic storage scenarios.

II. Core Technical Parameters

Nominal Diameter: DN50-DN600 (2″-24″)

Pressure Class: PN16/PN25/PN40 (1.6MPa/2.5MPa/4.0MPa)

Temperature Range: -46°C to 150°C (LCB steel down to -101°C)

Body Material: Cast steel WCB (normal temp), LCB (cryogenic), tensile strength ≥485MPa

Sealing System: Metal hard seal (STL overlay) + PTFE soft seal, leakage rate ≤0.1% (API 598)

Drive Type: Bevel gear manual drive (standard), optional electric/pneumatic actuators

Connection: Flanged (ASME B16.5, GB/T 9113), RF face

Protection Grade: IP65 (housing), anti-condensation design

Product Overview

III. Structural Design & Features

Cryogenic Optimization

Extended stem (protrusion ≥150mm) isolates cold media from operation mechanism, preventing frosting.

Fiberglass thermal gasket between bonnet and body reduces heat transfer by 60%, minimizing cold loss.

Bevel Gear Drive Benefits

2:1 gear ratio reduces DN300 valve torque from 280N·m to 85N·m, enabling single-hand operation.

Gearbox with lithium-based grease (-50°C to 120°C) extends maintenance cycle to 24 months.

Reliable Sealing

Double-eccentric gate-seat design self-laps sealing surfaces, compensating for ≤0.3mm wear.

V-type graphite packing + bellows dual sealing ensures zero leakage at 1.1x working pressure.

IV. Manufacturing & Quality Control

Cryogenic Material Treatment

Cast steel normalized at 920°C + tempered at 650°C, impact energy ≥27J at -40°C (Charpy V-notch).

STL6 overlay on seats aged at 500°C to eliminate stress, hardness HRC58-62.

Precision Machining

Lost foam casting for body, dimension tolerance ≤±0.8mm, surface roughness Ra≤12.5μm.

Bevel gears with ISO 8 class meshing, carburized and quenched (case depth 0.8-1.2mm).

Cryogenic Testing

Cryogenic treatment: -196°C liquid nitrogen immersion for 24h to detect intergranular corrosion.

Pressure cycling: 1,000 cycles at -46°C with no sealing degradation.