GB Marine Angle Valve
The GB Marine Angle Valve is a heavy-duty angle-pattern globe valve engineered in strict compliance with China’s mandatory national standards (GB) for shipbuilding and offshore service. It is purpose-built for isolating, throttling, and controlling media such as seawater, fresh water, fuel oil, lubricating oil, steam and compressed air aboard vessels. Manufactured under an audited quality system and typically supplied with type approval by China Classification Society (CCS) — and optionally by other IACS members — the valve offers full material traceability and proven reliability for marine engineers and shipyards worldwide. Its angle-body layout saves installation space, reduces turbulence, and directly adapts to standard ship piping arrangements.
Overview
1 Governing Standards & Design Basis
Product standards: Cast steel valves conform to GB/T 584, cast iron valves to GB/T 590, and bronze valves to relevant GB specifications; all define face-to-face dimensions, end-flange dimensions, and body design for the angle pattern.
Flange connection: Drilling and dimensions follow GB/T 2501 (ISO 7005-1 compatible) or GB/T 569, ensuring interchangeability with international pipework.
Pressure ratings: PN6, PN10, PN16, PN25 (GB/T 1048), covering low-pressure cooling to medium-pressure fuel and air lines.
Design reference: Built on long-established ship piping practice; select features also reference ISO 15761 or equivalent classification society rules.
2 Materials of Construction
Body/Bonnet: Cast steel WCB/LCB (GB/T 12229), grey cast iron HT200 (GB/T 9439), or tin bronze ZCuSn10Zn2 (GB/T 1176), selected according to fluid, temperature and corrosivity.
Disc & Seat: Stainless steel 12Cr18Ni9, aluminum bronze, or high-strength nitrile rubber for bubble-tight shut-off. Metal-to-metal and soft-seat options are available.
Stem: Stainless steel with rolled threads, delivering smooth handwheel operation and extended service life.
Packing: PTFE-impregnated, asbestos-free braided packing compliant with SOLAS fire safety requirements; optional gland arrangement for external adjustment.
3 Key Features
Space-saving angle body reduces pipe elbows and installation cost while optimizing flow path with lower pressure drop than straight pattern globe valves.
Rising stem & bolted bonnet give a clear visual open/close indication and allow convenient disassembly for inspection or polishing of seats.
Back-seat arrangement protects the stem packing when the valve is fully open, enhancing personnel safety.
Tight shut-off: Optional soft seat achieves zero leakage (Rate A per GB/T 13927), while metal-seated design meets the mandatory shell and seat leakage requirements for marine duty.
Marking: Permanent markings per GB/T 3032, showing material grade, heat number, PN, and nominal size for full lifecycle traceability.
4 Testing & Certification
Factory testing: Every valve undergoes shell strength test and seat tightness test in accordance with GB/T 13927 (or GB/T 26480 for specific marine applications); standard test pressure is 1.5× PN for shell and 1.1× PN for seat.
Type approval: CCS type approval certificate is standard; equivalent certificates from DNV, ABS, LR, BV or RINA can be supplied on request to match the vessel’s class.
Optional examinations: Radiographic or ultrasonic inspection of castings, low-temperature tests, and fire-safe certification per API 607 are available upon project demand.
5 Typical Applications
Ballast, bilge and drainage systems
Engine room cooling water and main fire-fighting lines
Fuel oil transfer, service and heating coil circuits
General auxiliary piping where rugged, leak-free isolation is mandatory
