KONGSBERG VT25-373-99X9 – Valve Position Transmitter for Marine Valve Control Systems

The KONGSBERG VT25-373-99X9 is a VT25-series valve position transmitter used on marine valve remote control systems—typically within ballast, bilge, cargo and utility lines. From my experience, this part is supplied as a direct-fit spare in KONGSBERG valve control architectures and is chosen for reliable 4–20 mA position feedback, robust sealing, and steady performance under shipboard shock and vibration. If you’re maintaining a K-Chief/K-Controller-based valve network, this unit seems to be the go-to for restoring clean position signals and keeping actuator feedback stable during maneuvers.

You might notice that suffix codes like “99X9” indicate variant differences (connector keying, range calibration, or mounting kit). In many cases, the electrical behavior stays the same, but the mechanical fit or cable interface changes. If you share your vessel build or BOM reference, we’ll match the exact variant before shipment.

Our Order Placement Process and Guarantees

• Quotation & model check. Send the part code and system location; we verify the variant against your drawings in hours, not days.
• Lead time. 1 week if in stock; no more than one month at the latest for backorders.
• Payment terms. 50% advance, full payment prior to delivery.
• Shipment. Express via FedEx, UPS, or DHL—packed for marine environments with moisture protection.
• Warranty. 365-day warranty on the part. DOA and early-life failures are replaced or credited after evaluation.

Key Features

• Marine-grade position feedback. Typically provides 4–20 mA proportional output for accurate valve/actuator position to the VCU or I/O rack.
• Ruggedized construction. Sealed housing and corrosion-resistant materials for harsh, humid engine-room or cargo-pump room conditions.
• Drop-in replacement. Variant-matched to existing brackets, connectors, and cable glands—reduces installation time.
• Stable under vibration. Designed for shipboard shock/vibration; in most cases, calibration drift is minimal between dockings.
• Service-friendly. Swappable without major rewiring; typical zero/span trim can be done onboard if required.
• Traceability. OEM-serialized with batch records to support class audits and lifecycle documentation.

Technical Specifications

Note: VT25 series variants can differ by connector orientation, range, or mounting kit. Values below reflect commonly supplied VT25 transmitter configurations used with KONGSBERG valve control units. Please confirm against your exact suffix.

Related or Supporting Products

• KONGSBERG VT25-373-99X8 – Same family transmitter; alternate connector/keying. Used when cable routing requires different gland orientation.
• KONGSBERG VT25-373-99A1 – Variant calibrated for 90° rotary actuators; typically identical wiring with a different mechanical kit.
• Valve Control Unit (VCU) – KONGSBERG controller that reads the 4–20 mA position and drives the solenoids. If your feedback is unstable, both the transmitter and the VCU input card should be checked.
• Marine M12 cable set (4–5 pin) – Shielded, oil-resistant pigtails for VT25 wiring in pump rooms and UMS spaces.
• Actuator mounting kit (MK-VT25-STD) – Brackets and hardware for retrofits when the original kit is missing or corroded.

Naming of variants may differ slightly by yard or build year. Share a photo of the nameplate or I/O drawing and we’ll align the correct suffix one-to-one.

Installation & Maintenance

• Environment. Mount on a clean, rigid actuator surface. Keep cable glands pointing downward where possible for drip-loops. Allow ventilation; avoid direct steam jets.
• Wiring. Use shielded marine-grade cable; ground the shield at the cabinet end. Typical loop power 24 VDC. Confirm polarity on the terminal legend.
• Cabinet interface. Route to the VCU/I-O cabinet per yard drawings. Keep analog signal cables away from VFD power cables to reduce noise.
• Calibration. After mechanical coupling, set zero at fully closed and span at fully open. Many crews do a quick two-point trim; it usually takes under 10 minutes.
• Routine checks. Quarterly visual inspection for moisture ingress, cable jacket damage, and bracket looseness. Wipe salt deposits with a damp cloth; avoid solvent sprays.
• Spare holding. For tankers and bulkers, keeping 1–2 spare VT25 units onboard minimizes downtime during port calls.
• Safety. Isolate actuator motion and de-energize the loop before removal. Verify area gas safety if installed in hazardous zones.

Quality & Certifications

• Compliance. Typically delivered with CE marking; materials and EMC designed for marine service. Many installations are accepted by DNV, ABS, or LR as part of the KONGSBERG system.
• RoHS/Reach. Supplied in line with current EU directives for electronic components unless a specific exemption applies to the marine variant.
• Warranty. 365-day warranty from shipment. Functional test reports can be provided on request.

Field note from a chief engineer last season: “Swapped the VT25 unit during bunkering. Calibration stuck the first time because of a loose coupling set-screw—tightened it, re-trimmed zero/span, and the VCU trend went flat and steady.” That’s typically how straightforward these replacements go when the variant matches.