Model RT-13P251 Submersible Mid Draft Pressure Sensor is custom-designed for ocean-going vessels’ mid-hull draft measurement. Made of full 316L stainless steel with flange mounting, IP68 fully submersible waterproof structure, converts seawater hydrostatic pressure into standard 4-20mA signal, real-time transmits ship mid draft data to cabin remote tank monitoring system. Widely equipped on bulk carriers, container ships, offshore engineering vessels for draft, trim & stability control.
Technical Specifications
Model No.: RT-13P251
Application: Ship MID DRAFT (Mid Hull Draft Monitoring)
Measuring Medium: Seawater, offshore brackish water
Measuring Range: Customizable 0~5m / 0~10m seawater
Output Signal: 4–20mA 2-wire
Accuracy: ≤0.25%FS
Material: Sensor Body & Flange: 316L Stainless Steel
Protection Grade: IP68, long-term underwater immersion
Operating Temp: -20℃ ~ +70℃
Cable: Marine shielded waterproof cable, customizable length
Installation: Flange fixed on ship hull outer plate
Certification: Support CCS Marine Product Certification
Serial Number: Custom engraved serial number for ship hull tracking
Key Features & Benefits
✅ Custom RT-13P251 Model For Ship MID DRAFT Measurement
✅ Full 316L Stainless Steel Body & Flange, Anti-seawater Corrosion, Anti-marine organism adhesion
✅ IP68 Deep Submersible Sealing, Integral vulcanized cable joint, zero water penetration risk
✅ Standard 4-20mA 2-wire signal, compatible with all marine remote level monitoring consoles
✅ High precision ≤0.25%FS, stable reading under rough sea & fluctuating seawater temperature
✅ Heavy-duty marine shielded cable, anti-electromagnetic interference on ship engine room
✅ CCS China Classification Society certification compliant, meets IMO marine equipment standards
✅ Flange mounting design, easy hull outer plate installation, customized cable length available
✅ Factory customized service: range, cable length, hull label marking for shipyard projects
Working Principle
The RT-13P251 mid draft sensor is a hydrostatic submersible level transmitter. When installed outside the ship mid hull, the bottom pressure diaphragm senses seawater static pressure, pressure value is linearly proportional to seawater depth. Internal high-stability circuit converts pressure signal into standard 4-20mA analog signal, transmits draft depth data to cabin control panel continuously, so crew can read real-time mid draft, calculate average draft and vessel trim.
Application Scenarios
1. Mid-hull draft monitoring for all ocean commercial vessels: bulk carrier, container ship, tanker, general cargo ship
2. Offshore engineering vessels, floating platforms draft measurement
3. Vessel ballast tank remote monitoring system supporting equipment
4. Shipyard newbuilding project custom draft sensor (support hull No. marking like XY117)
5. Vessel stability, trim, load draft real-time data acquisition for captain & engine room control
Structure Components:
316L stainless sensor body + anti-corrosion pressure diaphragm + vulcanized waterproof cable head + stainless mounting flange + marine heavy-duty shield cable
Maintenance & Daily Care
1. Routine Daily Inspection
①Check display value of draft monitoring console
Observe mid-draft reading continuously; if data jumps drastically, drifts or shows no signal, inspect the sensor and cable immediately.
②Cable appearance check
Inspect cable route along hull outer plate & cable tray: no abrasion, crack, oil corrosion or sharp bending. Avoid heavy compression from ballast water pipes and hull structures.
③Flange mounting tightness
During dry dock inspection, check all flange bolts for loosening, rust or water seepage at the welding joint between flange and hull plate.
④Junction waterproof head inspection
The vulcanized rubber cable joint must be intact, no cracking, peeling or seawater infiltration traces. Damaged rubber head will cause circuit short failure.
2. Dry Dock Maintenance (Every 1–2 Ship Drydocking Cycles)
①Sensor disassembly & surface cleaning
Remove the sensor from hull flange, use soft brush + fresh water to clear marine attachments (barnacles, algae, shellfish) on stainless steel body and pressure diaphragm.
Warning: Do not scrape diaphragm with hard metal tools to avoid permanent measurement damage.
②Diaphragm corrosion inspection
Check the bottom pressure sensitive diaphragm for pitting corrosion, perforation or deformation. Replace the sensor if corrosion spots penetrate the membrane.
③Seal & waterproof rework
Clean flange sealing surface, replace aging rubber gaskets; apply marine anti-rust sealant evenly on bolt threads.
④Cable full test
Use multimeter to test 4–20mA signal circuit continuity and insulation resistance. Replace cables with broken shielding layer or internal core wire breakage.
⑤Label & serial number protection
Wipe the metal nameplate with anti-salt spray cleaner, repaint faded text to avoid model RT-13P251, hull No. and serial number being unrecognizable.
3. Long-term Storage Maintenance (Spare Sensors Onboard)
①Store spare sensor in dry, ventilated cabin, avoid direct salt fog & high temperature near engine room.
②Wrap cable joint and diaphragm with anti-corrosion plastic film; apply anti-rust oil on flange metal surface.
③Conduct signal test once every 3 months for standby sensors to guarantee emergency replacement availability.
