Dosing Pump For Marine Sewage Treatment Plant

Product Introduction:

Our marine dosing pump is a high‑precision chemical metering pump purpose‑built for the demanding environment of onboard sewage treatment plants (STPs) . It is engineered to accurately inject a wide range of treatment chemicals—including sodium hypochlorite for disinfection, polyelectrolytes and coagulants for flocculation, and acidic or alkaline solutions for pH correction—directly into the biological or physicochemical treatment stages. Designed to comply with the latest IMO MEPC.227(64) and MEPC.159(55) resolutions, this pump guarantees that treated effluent consistently meets global discharge standards, while minimising chemical waste and operational costs.

Core Technology & Performance:

The pump features a robust diaphragm‑type metering mechanism, driven either by a maintenance‑free solenoid actuator or a heavy‑duty motor‑gearbox assembly, depending on the required flow and pressure range. With a standard flow capacity spanning from 0.5 to 120 L/h and a maximum backpressure of up to 16 bar, it delivers linear, pulsation‑damped injection with a steady‑state accuracy of ±1% of setpoint—even under severe suction pressure fluctuations or varying discharge conditions. The integrated stroke‑length and stroke‑frequency adjustment allow for a turndown ratio exceeding 100:1, ensuring precise dosing across the entire operating envelope.

Intelligent Control & System Integration:

Equipped with a microprocessor‑based digital controller, the pump offers both local manual adjustment and remote analog (4‑20 mA) or pulse signal control, enabling seamless integration with the STP’s PLC or SCADA system. The controller features a clear LCD display showing real‑time flow rate, totalised volume, alarm status, and maintenance reminders. An optional duty/standby configuration with automatic changeover logic ensures uninterrupted chemical supply during maintenance or fault conditions, a critical requirement for unmanned engine‑room operations. The pump also supports proportional dosing based on influent flow or turbidity signals, optimising chemical consumption in response to actual load variations.

Materials & Marine‑Grade Durability:

All wetted parts are constructed from chemically resistant materials—with pump head options in PVDF, PTFE, or 316L stainless steel—and the diaphragm is fabricated from reinforced PTFE, offering excellent resistance to chlorine, acids, and alkaline solutions. The external housing is powder‑coated aluminum or epoxy‑coated cast iron, supplemented with stainless steel fasteners, to withstand the saline, humid, and vibration‑prone environment typical of ship engine rooms. The valve balls and seats are available in ceramic, Hastelloy, or ruby, ensuring long service life and reliable sealing even when handling abrasive suspensions.

Safety, Maintenance & User‑Friendly Design:

For operational safety, the pump includes leak‑proof double‑diaphragm construction (with burst detection on request), pressure relief valves, and a dry‑run protection system that automatically shuts off the pump when the chemical tank level falls below a preset threshold. Maintenance is simplified by the quick‑release pump head and easily accessible valve assemblies; the diaphragm and valve parts can be replaced in situ within minutes without disconnecting the piping. A built‑in diagnostic routine continuously monitors motor temperature, stroke frequency, and suction pressure, alerting operators via visual or relay output before any critical failure occurs.

Compliance, Benefits & Application Scope:

Fully certified to MARPOL Annex IV and holding type‑approval from major classification societies (CCS, DNV, ABS, LR, BV), this STP dosing pump is the ideal solution for both newbuilding projects and retrofit upgrades. Its compact footprint—less than 0.1 m³—allows installation in confined spaces, while the low pulsation design reduces stress on downstream piping and valves. By delivering precise, on‑demand chemical dosing, the pump significantly reduces sludge volume, improves dewatering efficiency, and lowers the overall chemical consumption by up to 30% compared to traditional fixed‑rate dosing systems. Backed by a global service network and a standard 2‑year warranty, our dosing pump ensures reliable, cost‑effective, and environmentally sound operation throughout the vessel’s lifecycle.