Seawater Service Dual Plate Check Valve
Description
SEAWATER SERVICE DUAL PLATE WAFER CHECK VALVE – TECHNICAL DATA SHEET
(Ductile Iron Body / C95800 (Nickel-Aluminum Bronze) Disc / EPDM Seat)
Project Name: ________________________
Item No.: ________________________
Tag No.: ________________________
Quantity: ________________________
Date: ________________________
1. VALVE GENERAL INFORMATION
| Parameter | Specification |
|---|---|
| Valve Type | Dual Plate Wafer Check Valve (Spring Assisted, Non-Slam) |
| Body Construction | Wafer Type – Fits between pipe flanges |
| Body Material | Ductile Iron (ASTM A536 Grade 65-45-12 / EN-GJS-450-10) |
| Disc / Plate Material | C95800 – Nickel-Aluminum Bronze (ASTM B148) |
| Seat Material | EPDM (Ethylene Propylene Diene Monomer) – Bonded/Lined type |
| Stem / Hinge Pin Material | Stainless Steel (Duplex 2205 / AISI 316) – Seawater grade |
| Spring Material | Stainless Steel (AISI 316 / Duplex 2205) – Corrosion resistant for marine environment |
| Bushings / Bearings | PTFE / Bronze-backed PTFE (seawater compatible) |
| Nominal Size (DN / NPS) | 2″ – 24″ (DN50 – DN600) / Up to 48″ (DN1200) available |
| Pressure Rating | Class 125 / Class 150 / PN10 / PN16 |
| End Connection | Wafer Type |
| Design Standard | API 594 / API 6D / ASME B16.34 / ISO 5752 |
| Face-to-Face Standard | API 594 Short Pattern / ISO 5752 Series 20 |
| Flange Drilling Standard | ASME B16.5 (Class 150) / ASME B16.47 / EN 1092-2 / JIS B2220 |
| Inspection & Test Standard | API 598 / ISO 5208 / EN 12266-1 |
| Temperature Range | -30°C to +120°C (EPDM Seat) |
| Primary Service | Seawater, Brackish Water, Marine Applications, Offshore Platforms |
2. MATERIALS OF CONSTRUCTION (SEAWATER GRADED)
| No. | Component | Material | Remarks |
|---|---|---|---|
| 1 | Body | Ductile Iron (ASTM A536 65-45-12) | Heavy-duty fusion-bonded epoxy coating (min. 300 μm, WRAS approved) for seawater resistance |
| 2 | Plates / Discs (2 pcs) | C95800 – Nickel-Aluminum Bronze (ASTM B148) | Excellent cavitation & corrosion resistance in seawater; high strength |
| 3 | Seat | EPDM Rubber (Seawater grade) | Bonded to body; resistant to saline corrosion and ozone |
| 4 | Springs (2 pcs) | Stainless Steel (Duplex 2205 / AISI 316) | High tensile, corrosion-resistant for cyclic marine duty |
| 5 | Hinge Pin / Stem | Duplex Stainless Steel (2205) / AISI 316 | Central pivot pin; anti-galling in seawater |
| 6 | Stop Pin / Limiter | Duplex Stainless Steel (2205) | Limits plate travel, resists pitting |
| 7 | Bushings / Bearings | PTFE / Aluminum-Bronze backed | Low friction, maintenance-free in wet environments |
| 8 | Nameplate | Stainless Steel 316L | Laser-engraved, permanently attached |
| 9 | Fasteners (if any) | Duplex 2205 / AISI 316 | For lug type or accessories |
All materials are selected for resistance to chloride-induced pitting, crevice corrosion, and stress corrosion cracking (SCC) in seawater service.
3. DESIGN FEATURES (SEAWATER OPTIMIZED)
| Feature | Description | Benefit |
|---|---|---|
| C95800 Nickel-Aluminum Bronze Discs | High-strength bronze alloy with exceptional resistance to seawater corrosion | Prevents dezincification and cavitation damage; long service life in marine environments |
| Heavy-Duty Epoxy Coating (Body) | Fusion-bonded epoxy applied internally & externally (min. 300 μm) | Isolates ductile iron body from direct seawater contact, preventing galvanic corrosion |
| Duplex 2205 / 316 Stainless Steel Springs & Pins | Premium corrosion-resistant alloys matched to marine environment | Resists chloride pitting; ensures reliable spring closure in saline atmospheres |
| EPDM Soft Seat (Seawater Grade) | Resilient EPDM formulated for brackish/saline media | Bubble-tight shut-off; resists swelling and degradation in seawater |
| Non-Slam Closure | Spring-assisted plates close before flow reversal | Eliminates water hammer and protects downstream equipment in offshore systems |
| Compact Wafer Design | Short face-to-face per API 594 | Minimizes weight and space on offshore platforms |
| Bi-Directional Flow | Seals in both directions (marking provided) | Simplified installation in complex piping layouts |
| Corrosion Allowance | Additional thickness on all wetted parts | Provides a safety margin against long-term seawater erosion |
4. APPLICABLE STANDARDS & SPECIFICATIONS
| Item | Standard |
|---|---|
| Design & Manufacturing | API 594, API 6D, ASME B16.34 |
| Face-to-Face Dimensions | API 594 Short Pattern / ISO 5752 Series 20 |
| Flange Connection | ASME B16.5, ASME B16.47, EN 1092-2, JIS B2220 |
| Inspection & Testing | API 598, ISO 5208, EN 12266-1 |
| Coating Standard | WRAS approved fusion-bonded epoxy; NORSOK M-501 (offshore coating) available on request |
| NACE Standard | NACE MR0175 / MR0103 (materials compliance available upon request) |
| Valve Marking | MSS SP-25 |
5. PRESSURE TEST (PER API 598 / ISO 5208)
| Test Type | Pressure | Medium | Acceptance Criteria |
|---|---|---|---|
| Shell (Hydrostatic) | 1.5 × Rated Pressure (Class 150 / PN16) | Seawater or Fresh Water | No visible leakage through shell |
| High Pressure Seat Test | 1.1 × Rated Pressure | Water | Zero leakage (bubble-tight) per ISO 5208 Rate A |
| Low Pressure Seat Test | 5–6 bar (80–90 psi) | Air or Nitrogen | Zero leakage (bubble-tight) |
100% hydrostatic shell and seat tests, plus low pressure air test performed on every valve. Seat leakage test conducted in both directions (bi-directional check).
6. PERFORMANCE DATA (SEAWATER SERVICE)
| Parameter | Specification |
|---|---|
| Service Medium | Seawater, Brackish Water, Produced Water, Marine Cooling Water |
| Design Temperature | -30°C to +120°C (EPDM Seat limitation) |
| Max. Working Pressure | Class 150 / PN16 (19 bar @ 100°C) |
| Leakage Class | ISO 5208 Rate A / API 598 (Bubble-tight, zero leakage) |
| Cracking Pressure | Very low (approx. 0.02–0.05 bar) – suitable for gravity or low-pressure seawater lines |
| Installation Position | Horizontal (preferred) or Vertical Upwards |
| Flow Direction | Bi-directional (marked on body; recommended orientation per arrow) |
| Max. Flow Velocity (Seawater) | ≤ 6 m/s (to limit erosion/cavitation on C95800 discs) |
| Galvanic Compatibility | C95800 disc is cathodic to DI body; epoxy coating effectively isolates galvanic couple |
7. DIMENSIONS (Reference – API 594 Short Pattern, Class 150)
| DN (mm) | NPS (inch) | Face-to-Face L (mm) | Approx. Weight (kg) | Flange Drilling (ASME B16.5 CL150) |
|---|---|---|---|---|
| 50 | 2″ | 54 | 4.5 | 4 × 19mm on 120.7mm BC |
| 80 | 3″ | 57 | 7.5 | 4 × 19mm on 152.4mm BC |
| 100 | 4″ | 64 | 11.0 | 8 × 19mm on 190.5mm BC |
| 150 | 6″ | 76 | 20.0 | 8 × 22mm on 241.3mm BC |
| 200 | 8″ | 95 | 35.0 | 8 × 22mm on 298.5mm BC |
| 250 | 10″ | 108 | 58.0 | 12 × 26mm on 362.0mm BC |
| 300 | 12″ | 143 | 85.0 | 12 × 26mm on 431.8mm BC |
| 350 | 14″ | 184 | 130.0 | 12 × 29mm on 476.3mm BC |
| 400 | 16″ | 192 | 185.0 | 16 × 29mm on 539.8mm BC |
| 450 | 18″ | 203 | 245.0 | 16 × 32mm on 577.9mm BC |
| 500 | 20″ | 219 | 320.0 | 20 × 32mm on 635.0mm BC |
| 600 | 24″ | 254 | 460.0 | 20 × 35mm on 749.3mm BC |
For PN16 / EN 1092-2 drilling patterns, please refer to specific flange standards. Dimensions are subject to manufacturing tolerances.
8. OPTIONAL UPGRADES (SEAWATER / MARINE)
| Option | Description |
|---|---|
| Spring Material | Inconel X-750 / Alloy 20 for extreme seawater / high-temperature conditions |
| Stem / Hinge Pin | Super Duplex (UNS S32750 / 2507) for maximum pitting resistance (PREN > 40) |
| Body Coating | NORSOK M-501 approved coating / 3-layer epoxy-glass flake for offshore splash zones |
| Seat Material | NBR, Viton (for oil-contaminated seawater), or Silicon |
| Disc Material Upgrade | Alloy C95800 with additional erosion-resistant hard-facing on sealing edges |
| End Connection | Lugged type for dead-end service, or Flanged (RF/FF) |
| Actuation | Lever lock, chainwheel, electric / pneumatic / hydraulic actuator for automated systems |
| Certification | DNV-GL / ABS marine type approval, PED 2014/68/EU, SIL 2/3 |
| Inspection | 100% PMI (Positive Material Identification) for C95800 and Duplex components |
| Hydrostatic Testing Medium | Synthetic seawater (ASTM D1141) for realistic corrosion assessment |
9. QUALITY CONTROL (SEAWATER GRADE VERIFICATION)
-
100% chemical analysis and PMI verification on all C95800 discs, Duplex pins, and 316 springs per heat number
-
100% DPT (dye penetrant) examination on all castings and disc edges; MT / UT / RT available on request
-
100% hydrostatic shell and seat tests performed in both flow directions
-
Coating thickness measured with DFT gauge (minimum 300 μm) with holiday (spark) testing for pinhole detection
-
Hardness check on C95800 discs per ASTM B148 requirements
-
Dimensional inspection with calibrated instruments per API 594
-
Destructive and non-destructive testing (NDT) records maintained for full traceability
10. WARRANTY
12 months service life at minimum against manufacturing defects; free spares and maintenance instruction provided when required.
This technical data sheet is for reference purposes only. All specifications are subject to change without prior notice. For specific project requirements (including offshore class approval), please consult the manufacturer.
