Marine Cast Steel Diaphragm Pump

I. Product Overview

The marine cast steel diaphragm pump is a positive displacement conveying equipment specially designed for the complex working conditions of ships. Key components such as the pump body and valve seat are mainly made of cast steel, matched with a flexible diaphragm as the isolation and transmission element. It changes the volume of the pump chamber through the reciprocating movement of the diaphragm to achieve leak-free and stable conveying of various media. This pump abandons the shaft seal structure of traditional pumps, fundamentally solving the common leakage problem in ship conveying processes. At the same time, cast steel has excellent compressive strength, impact resistance and corrosion resistance, which can easily resist the erosion of harsh marine environments such as seawater salt spray, ship vibration, and alternating high and low temperatures.

As one of the core equipment of the ship's conveying system, the marine cast steel diaphragm pump is widely used in key scenarios such as fuel oil conveying, lubricating oil circulation, seawater desalination supply, sewage discharge, and chemical additive injection. It can adapt to various media such as diesel oil, heavy oil, lubricating oil, seawater, sewage, and acid-base solutions. The product strictly complies with international and domestic standards such as the International Convention for the Safety of Life at Sea (SOLAS), ISO 15749 Marine Positive Displacement Pump Standard, and GB/T 10832 Marine Pump Technical Requirements. It has obtained type approval from mainstream classification societies such as China Classification Society (CCS) and American Bureau of Shipping (ABS), and is suitable for various ships and marine engineering equipment such as cargo ships, oil tankers, passenger ships, container ships, offshore drilling platforms, and ocean-going research vessels.

II. Core Technical Parameters

Flow Range: 0.5-100 m³/h, supporting graded configuration according to ship conveying needs. The flow pulsation rate under rated working conditions is ≤±2%, ensuring stable and uniform medium conveying.

Pressure Range: 0.6-1.6 MPa, up to 2.5 MPa at maximum. It can meet different pressure requirements such as long-distance pipeline conveying and high-pressure injection of ships, and is compatible with various pressure levels of ship systems.

Medium Adaptability: Can convey media such as diesel oil, heavy oil, lubricating oil, seawater, fresh water, ship sewage, fuel additives (desulfurizers, combustion improvers), and weak acid-base solutions; the applicable medium temperature range is -20℃ to 120℃, and it can handle suspended impurity media with solid content ≤5% (particle size ≤2mm).

Drive Mode: Supports three drive modes: pneumatic, hydraulic and electric. Pneumatic drive is compatible with the ship's compressed air system, with fast response speed and excellent explosion-proof performance; hydraulic drive has strong power, suitable for large-flow and high-pressure scenarios; electric drive is energy-saving and stable, suitable for conventional conveying needs.

Material Parameters: The pump body and valve seat are made of high-quality cast steel (ZG230-450, ZG310-570), the diaphragm is made of fluoroelastomer (FKM) or polytetrafluoroethylene (PTFE), and the seal is made of fluoroelastomer, ensuring material adaptability and service life.

Operating Performance: Self-priming height ≥5m, self-priming time ≤60 seconds (at a suction lift of 3m); operating noise ≤72dB(A), vibration acceleration ≤2.0m/s², complying with the noise control standards for ship cabins.

III. Structural Design and Core Advantages

3.1 Core Structural Design

Integral Cast Steel Pump Body: Formed by integral casting process, the pump body has a compact structure and high strength. The weld-free design avoids pressure leakage caused by welding defects, can withstand high-pressure medium impact, and is suitable for complex working conditions such as ship jolting and vibration.

Leak-Free Diaphragm Structure: Adopts a double-diaphragm symmetrical design, equipped with a diaphragm rupture monitoring device. Once the diaphragm is damaged, it can immediately send an alarm signal and shut down the machine to prevent medium leakage from polluting the marine environment or damaging drive components; the diaphragm is made of enhanced wear-resistant material, with a service life ≥8000 hours.

Multi-Functional Valve Group Design: The built-in inlet valve and outlet valve adopt spherical or disc-type structures, with good one-way sealing performance, which can effectively prevent medium backflow; the valve seat adopts a replaceable design, which can be replaced without disassembling the entire pump body after wear, reducing maintenance difficulty.

Compact Installation Layout: Supports multiple installation methods such as horizontal, vertical and wall-mounted, with small volume and light weight, suitable for the limited space of ship cabins; the base is equipped with shock absorption and buffering devices to reduce the resonance impact between pump operation and ship navigation.

3.2 Core Technical Advantages

Ultimate Leak-Free Guarantee: No shaft seal or packing seal design, completely eliminating the risk of medium leakage. It is especially suitable for the conveying of flammable, explosive, toxic and harmful media such as fuel oil and chemical additives, complying with ship environmental protection and safety requirements.

Super Strong Environmental Adaptability: The cast steel material has undergone special anti-corrosion treatment, no rust occurs in 2000-hour salt spray test, and it can withstand long-term erosion of seawater, salt spray and humid atmosphere; the pump body can withstand the ship's navigation attitude of heeling ±35° and trimming ±25°, and operate stably under harsh sea conditions such as storms and huge waves.

Wide Medium Compatibility: Can easily adapt to high-viscosity, impurity-containing and corrosive media without additional filtering devices; different medium conveying needs can be quickly adapted by replacing the diaphragm and seals, realizing "one pump for multiple uses" and reducing the cost of ship equipment configuration.

Safe, Reliable and Easy to Maintain: Equipped with multiple safety devices such as overload protection, diaphragm rupture alarm and abnormal pressure alarm; key components adopt modular design, which is convenient for disassembly and replacement. Daily maintenance does not require professional tools, and the maintenance time is ≤30 minutes, greatly improving the efficiency of ship operation and maintenance.

Energy-Saving and Efficient Operation: Adopts optimized fluid mechanics design, with volumetric efficiency ≥95%. Under the same conveying conditions, the energy consumption is 10%-15% lower than that of traditional gear pumps; no priming is required for startup, and it has strong self-priming capacity, suitable for low-liquid-level medium conveying scenarios of ships.

IV. Typical Application Scenarios

4.1 Ship Fuel Oil Conveying System

As the core equipment for fuel oil conveying of the ship's main engine and auxiliary engine, the marine cast steel diaphragm pump can stably convey different grades of fuel oil such as 0# diesel oil, -10# diesel oil and high-sulfur heavy oil. The leak-free design avoids fuel waste and fire risks; the cast steel pump body is resistant to high pressure and impact, can adapt to pressure fluctuations in the ship's fuel oil pipeline, ensure stable fuel supply to the engine, and guarantee reliable power output of the ship.

4.2 Lubricating Oil Circulation and Supply

In the lubricating oil system of key transmission components such as the ship's main engine, generator and propeller, this pump is responsible for the circulation and regular supply of lubricating oil. The gentle conveying method avoids oxidative deterioration of lubricating oil, the leak-free design ensures the purity of lubricating oil and reduces wear of transmission components; it is suitable for the conveying needs of high-viscosity lubricating oil and can operate stably in low-temperature environments, ensuring sufficient lubrication of equipment.

4.3 Seawater and Sewage Treatment System

In the ship's seawater desalination system, as a seawater lift pump, it extracts seawater from the sea to the desalination device. The strong corrosion resistance of cast steel resists seawater erosion and ensures long-term stable operation; in the ship's sewage treatment system, it can efficiently convey ship domestic sewage and bilge sewage containing impurities and corrosive substances. The leak-free design avoids marine environmental pollution by sewage and complies with the requirements of IMO Marine Environmental Protection Convention.

4.4 Chemical Additive Injection System

In the fuel oil desulfurization and combustion enhancement systems of ships such as oil tankers and chemical tankers, it is used for high-pressure injection of chemical additives such as desulfurizers and combustion improvers. Precise flow control ensures accurate additive ratio, and the leak-free design prevents chemical media from corroding drive components or polluting the environment; the cast steel pump body has strong compatibility with chemical media and 

s suitable for the conveying needs of different additives.

4.5 Special Conveying on Offshore Platforms

In the drilling fluid conveying, chemical agent injection and seawater cooling systems of offshore drilling platforms, the marine cast steel diaphragm pump adapts to the harsh marine environment of the platform with its strong corrosion resistance and vibration resistance; it can stably convey complex media such as sand-containing drilling fluid and corrosive chemical agents, providing reliable conveying guarantee for the normal operation of the platform.