Specification
TIANYU 316 Stainless Steel Marine Seawater Valves: Corrosion-Resistant Solutions for Harsh Ocean Environments
I. Product Overview
II. Key Attribute Parameters
-
Structure & Specifications
- Nominal Diameter Range: DN15–DN300 (1/2″–12″)
- Connection Type: Flanged (ANSI B16.5, DIN 2501, JIS B2220)
- Valve Types: Gate valves, globe valves, check valves, ball valves, butterfly valves
- Material: Main body 316 stainless steel (molybdenum content 2–3%), sealing surfaces overlaid with Stellite alloy
-
Performance Parameters
- Working Pressure: 1.6 MPa–10 MPa (Class 150–Class 600)
- Temperature Range: -40°C–200°C
- Flow Coefficient: Cv value 10–1200 (water medium)
- Sealing Class: Complies with API 598 Class VI zero-leakage standard
-
Certifications
- Marine Classification Societies: DNV-GL, ABS, LR, BV, CCS, etc.
- Environmental Compliance: IMO MEPC.175(58) Ballast Water Convention
- Material Standards: ASTM A182, EN 10222
Product Overview
II. Key Attribute Parameters
-
Structure & Specifications
- Nominal Diameter Range: DN15–DN300 (1/2″–12″)
- Connection Type: Flanged (ANSI B16.5, DIN 2501, JIS B2220)
- Valve Types: Gate valves, globe valves, check valves, ball valves, butterfly valves
- Material: Main body 316 stainless steel (molybdenum content 2–3%), sealing surfaces overlaid with Stellite alloy
-
Performance Parameters
- Working Pressure: 1.6 MPa–10 MPa (Class 150–Class 600)
- Temperature Range: -40°C–200°C
- Flow Coefficient: Cv value 10–1200 (water medium)
- Sealing Class: Complies with API 598 Class VI zero-leakage standard
-
Certifications
- Marine Classification Societies: DNV-GL, ABS, LR, BV, CCS, etc.
- Environmental Compliance: IMO MEPC.175(58) Ballast Water Convention
- Material Standards: ASTM A182, EN 10222
III. Structural Design & Technical Features
-
Seawater Corrosion Resistance Design
- 316 stainless steel base with molybdenum content ≥2%, pitting resistance equivalent number (PREN) ≥40
- Sealing surfaces overlaid with 500-μm-thick Stellite 6 alloy, hardness HRC ≥40, resistant to erosion and wear
- Valve stems made of 2205 duplex stainless steel, yield strength ≥450 MPa, resistant to stress corrosion cracking
-
Anti-Marine Biofouling Technology
- Electropolished inner surfaces (Ra ≤0.4 μm) to minimize marine organism adhesion
- Optional sacrificial anode protection system (zinc alloy) with protection efficiency ≥95%
-
Low-Maintenance Structure
- Bonnet 采用 pressure self-tightening sealing design for enhanced sealing under increasing pressure
- Union bolt connections enable disassembly in ≤15 minutes (DN100 size)
IV. Manufacturing Process & Quality Control
-
Core Processes
- Forging Process:
- Valve bodies forged with a forging ratio ≥3 and grain size ≥5
- Solution treatment at 1050°C to eliminate residual stresses
- Precision Machining:
- Valve seat sealing surfaces machined using 5-axis linkage technology with flatness ≤0.005 mm
- Valve stem straightness ≤0.02 mm/m to ensure stable opening and closing torque
- Forging Process:
-
Quality Testing
- Non-Destructive Testing: UT ultrasonic testing (ASTM A388), MT magnetic particle testing (ASTM E709)
- Pressure Testing:
- Shell test: 1.5 times rated pressure (5-minute hold)
- Sealing test: 1.1 times rated pressure (bubble-tight sealing)
- Salt Spray Test: ASTM B117-16 standard, 1000 hours without corrosion
Valve Details
V. Core Product Advantages
| Advantage Dimension | Technical Details & Application Value |
|---|---|
| Corrosion Resistance Lifespan | Annual corrosion rate ≤0.05 mm in 3.5% NaCl solution, designed service life ≥20 years, 5 times longer than carbon steel valves. |
| High-Pressure Resistance | Gate valves maintain sealing specific pressure ≥100 MPa at 10 MPa, ensuring safety in deep-sea applications (1000-meter water depth). |
| Rapid Response | Pneumatic actuator response time ≤0.5 seconds (DN100 size) for emergency shutdown requirements. |
| Total Cost of Ownership | Maintenance cycle ≥5 years, 40% lower total cost than cast iron valves and 25% lower than bronze valves. |
Application
VI. Application Fields & Case Studies
-
Ship Ballast Water Systems
- Scenario: Ballast water inlet/outlet control for a 200,000 DWT oil tanker
- Configuration: DN250 electric butterfly valve, 316 stainless steel + EPDM seals
- Result: Resistant to chloride ions (Cl⁻ content ≥20,000 ppm), opening/closing torque ≤150 N·m
-
Offshore Platform Seawater Cooling Systems
- Scenario: Seawater cooling pipeline for an FPSO platform in the South China Sea
- Configuration: DN300 check valve, duplex stainless steel disc + Stellite sealing surface
- Advantage: Resistant to high-velocity seawater scouring (flow velocity ≥5 m/s), water hammer pressure ≤1.5 times working pressure
-
Offshore Wind Power Foundation Protection
- Scenario: Seawater flushing system for offshore wind turbine jacket legs
- Configuration: DN80 pneumatic globe valve with sacrificial anode protection
- Feature: 60% improvement in corrosion resistance in the splash zone (tidal range)
VII. Selection & Installation Guide
-
Key Selection Parameters
- Seawater Parameters: Salinity (typically 3.2–3.7%), temperature (-2°C–35°C), sediment content
- Installation Location: Above deck (UV protection required), bilge (explosion-proof required), ballast tanks (mud resistance required)
- Operation Mode: Manual (≤DN150), electric (DN150–DN300), pneumatic (emergency shutdown)
-
Installation Notes
- Use full-metal serrated gaskets (ASME B16.20) for flange connections with pre-tightening force deviation ≤±5%
- Install horizontally with the valve stem vertical to prevent Fluid accumulation at the stem
- For welded connections, use ER316L welding wire and perform stress relief treatment at 620°C for 2 hours after welding
RELATED
-
API 609 ASME B16.5 Class150 NPS10 ASTM B148 C95800 Nickel Aluminum Bronze Manual Double Offshore Eccentric Flanged Butterfly Valve
I. Important Attribute Specifications A. Material Composition TIANYU double eccentric butterfly valve is constructed with corrosion-resistant alloy ma…
BUTTERFLY VALVE 09/23/2026 -
API 600 ASME B16.5 Class 150 NPS 1“ ASTM B148 C95800 Nickel Aluminum Bronze Flexible Wedge OS&Y Flanged Gate Valve with Handwheel Operation for Marine Seawater Offshore and Coastal Industrial Piping
I. Important Attribute Specifications A. Material Composition TIANYU flexible wedge gate valves are engineered with a material matrix carefully select…
GATE VALVE 09/23/2026 -
API594 ASME 6“ Class150LB Replaceable Rubber Liner & SS304 Blade Ductile Iron Wafer Manual Slurry Knife Gate Valve
I. Important Attribute and Specification Description A. Global Standard Compliance & Product Core Definition The TIANYU Wafer Slurry Knife Gate Va…
GATE VALVE 07/09/2026 -
API 600 ASME CE DN80 Class 300LB WC6 Cr-Mo Alloy Steel Manual Flanged Rising Stem Wedge Gate Valve
I. Important Attribute and Specification Description A. Global Standard Compliance & Product Core Definition The TIANYU Rising Stem Gate Valve is …
GATE VALVE 07/02/2026 -
API 602 ASME DN80 Class 300LB ASTM A216 WCB Manual Flanged Straight Pattern Globe Valve With Metal-to-Metal Trim with Flexible Graphite Stem Packing
I. Important Attribute and Specification Description A. Global Standard Compliance & Product Core Definition The TIANYU Straight Pattern Globe Val…
GLOBE VALVE 07/02/2026 -
API 594 ASME B16.5 CE DN80 Class 150LB ASTM A216 WCB Flanged Swing Check Valve
I. Important Attribute and Specification Description A. Global Standard Compliance & Product Core Definition The TIANYU Swing Check Valve is a bol…
CHECK VALVE 07/02/2026



