Product Overview
The Nakakita NSVBT732 is a pneumatic indicating controller designed to regulate the viscosity of heated fuel oil supplied to marine diesel engines.
It receives the measurement from a connected viscosity transmitter, displays the fuel-oil viscosity and generates a proportional pneumatic control signal. This signal operates the steam control valve serving the fuel-oil heater, maintaining the viscosity required for efficient combustion.
Technical Specifications
| Product information | Details |
|---|---|
| Manufacturer | Nakakita Seisakusho Co., Ltd. |
| Model | NSVBT732 / NS-VBT-732 |
| Product type | Pneumatic viscosity indicating controller |
| Primary application | Main-engine fuel-oil viscosity control |
| Typical scale range | 0–30 cSt |
| Alternative indication | 0–3 × 10 cSt and 0–12.5 Redwood No. 1 |
| Supply-air pressure | 1.4 kgf/cm² |
| Pneumatic control output | 0.2–1.0 kgf/cm² |
| Equivalent output | Approximately 20–100 kPa |
| Control action | PI or PID pneumatic control |
| Adjustments | Proportional band, reset time and rate time |
| Local indication | Analogue viscosity scale |
| Controlled equipment | Fuel-oil heater steam-control valve |
| Associated equipment | Nakakita viscosity transmitter |
| Electrical supply | Not required for pneumatic operation |
| Typical installation | Marine fuel-oil conditioning and booster system |
| Approximate controller weight | 3.94 kg |
Product Description
The NSVBT732 compares the measured fuel-oil viscosity with the selected setpoint. When viscosity changes, the controller adjusts its pneumatic output to reposition the heater’s steam-control valve.
Increasing or reducing the steam supply changes the fuel temperature and consequently its viscosity. The proportional, reset and rate adjustments allow the response to be matched to the characteristics of the vessel’s fuel system.
Its mechanical indication and pneumatic operation make it suitable for continuous engine-room service, including conventional heavy-fuel-oil heating and conditioning systems.
