Applications of Wilden® Pneumatic Diaphragm Pumps in the Marine Industry

In the marine environment, the challenges faced by pumping equipment are far more severe than those on land. Seawater 

corrosion, the complexity of oily bilge water, strict requirements in explosion-proof areas, and maintenance challenges caused

 by limited ship space - these problems make many traditional pump types "acclimated" on ships. With its unique technical

 architecture, Wilden® air-operated double diaphragm pumps (AODD) are becoming the choice of more and more shipowners

 and shipyards.

1. Core challenges faced by ship fluid transportation

The fluid transportation task in ship operations is far from being as simple as “moving liquid from point A to point B”. The 

following types of typical problems must be faced when selecting marine pump equipment:

1. The medium composition is complex: Bilge water is often mixed with seawater, lubricating oil, fuel, rust residue, sediment 

and other components. Traditional centrifugal pumps are prone to cavitation or blockage when faced with media containing

 solid particles, and frequent failures seriously affect ship operations.

2. High explosion-proof safety requirements: There are flammable and explosive risks in oil tanker cargo holds, fuel transfer 

areas, engine rooms and other places. The use of electric pumps in these areas requires complex explosion-proof design and 

certification.

3. The installation space is limited: The internal space of the ship is very valuable, so the equipment needs to be as lightweight 

and compact as possible, and at the same time, it must be easy to maintain and replace in a small space.

4. Changeable operating conditions: The ship may face tilting and rolling during navigation, the pumping task may be intermittent, 

and the flow and lift requirements change frequently.

5. Unstable power supply: In emergencies or in certain specific areas, there may be no reliable power supply, requiring equipment 

to operate independently from the grid.

2. Why is Wilton pneumatic diaphragm pump suitable for ships?

Since Wilton invented the world's first pneumatic double diaphragm pump in 1955, it has been deeply involved in the field of AODD

 pump technology for nearly 70 years. Its products have accumulated rich application experience in the fields of shipbuilding and 

offshore engineering. The following core technical features make it perform excellently in ship operating conditions:

Intrinsically safe, explosion-proof and worry-free: Wilton pumps are completely powered by compressed air and no sparks are 

generated. The Pro-Flo® SHIFT Air Distribution System (ADS) made of metal can be grounded, meets ATEX explosion-proof 

certification requirements, and can be used safely in explosive environments such as oil tankers and chemical tankers.

Self-priming and dry running capabilities: It can start by self-priming without priming the pump, and the dry suction height can

 reach 7 meters. Even if there is no liquid in the pump, idling operation will not damage the pump body. This feature is particularly

 important in intermittent work such as bilge drainage.

Ability to pass solid particles: Wilden pumps have no closely fitting parts, and solid particles can pass through the pump body 

without causing damage. The maximum particle size that can pass through is 6.4mm or higher - which means that rust and 

sediment in the bilge water will not easily cause blockage.

Lockable operation: When the outlet pipeline is closed, the pump will automatically slow down or stop, and will not burn the 

motor or cause the pipe to burst like a centrifugal pump.

Adjustable flow and pressure: control the head by adjusting the inlet pressure (up to 8.6 BAR), and accurately control the flow 

by adjusting the air volume. Different models cover the flow range from 18 LPM to 1174 LPM.

Rich material choices: the pump body can be made of aluminum alloy, cast iron, stainless steel, Hastelloy, etc.; the diaphragm 

can be made of neoprene, nitrile rubber (NBR, oil resistant), fluororubber (FKM/Viton®, high temperature resistant up to 176°C), 

ethylene propylene diene monomer rubber (EPDM, low temperature resistant to -51°C), WIL-FLEX® (strong acid and alkali resistant), 

Teflon (PTFE, ultimate corrosion resistance) and other materials. It can be flexibly selected according to the specific chemical 

characteristics of the conveying medium.

Easy maintenance: The clamp structure design requires no special tools for disassembly and assembly. The marine engineering 

training course at the Massachusetts Maritime Academy in the United States even has a practical training program for the disassembly, 

assembly and maintenance of Wilton diaphragm pumps.

3. Typical application scenarios of ships

1. Bilge Stripping

This is one of the most common applications for Wilton pumps on ships. The composition of bilge water is complex—seawater,

 lubricating oil, fuel, rust residue, and sediment are mixed in it. With its self-priming ability, solid particle passing ability and 

explosion-proof characteristics, Wilden pumps can efficiently complete intermittent pumping tasks, avoiding frequent failures

 caused by cavitation or blockage of traditional centrifugal pumps. In practical applications on ocean-going cargo ships, the 

monthly maintenance time due to blockage was significantly reduced after using pneumatic diaphragm pumps to treat bilge water.

2. Ballast Water Treatment

The injection and discharge of ballast water are important aspects of daily ship operations. Wilden pumps can be used to transport 

ballast water. Their materials are resistant to seawater corrosion, and diaphragm materials suitable for seawater conditions can be 

selected as needed. Wilden pumps are also used to remove deposited sludge during ballast tank sludge cleaning operations.

3. Fuel and lubricating oil transportation

The transportation of fuel and lubricating oil has strict requirements on the explosion-proof performance and oil resistance of 

the pump. Wilden pumps can be equipped with nitrile rubber (NBR) diaphragms, which are specially designed for petroleum 

media (diesel, hydraulic oil, kerosene, leaded gasoline, etc.). Its intrinsically safe properties make it ideal for use in engine rooms 

and fuel tank areas.

4. Deck washing and seawater transportation

Deck washing requires the extraction of seawater, which is highly corrosive to metal parts. Wilton pumps can be equipped with 

aluminum alloy or stainless steel pump bodies and seawater corrosion-resistant diaphragm materials to complete tasks such as

 deck washing and equipment cleaning.

5. Firefighting water transportation (Firefighting)

In emergency situations such as firefighting, Wilton pumps can be quickly deployed and put into operation. It does not require 

electricity and can be started quickly, which has unique advantages in emergency situations.

6. Wastewater Transfer

Wilden pumps are also suitable for the collection and discharge of ship domestic sewage and oily sewage. Its low shear properties 

avoid destroying microbial flora that may be present in wastewater.

7. Chemical and material transportation

Corrosive chemicals are often transported on chemical tankers and offshore platforms. Wilton TZ1 series is made of stainless steel, 

has excellent corrosion resistance, and is suitable for chemical fluid transportation. PTFE diaphragms as the ultimate anti-corrosion

 solution for extremely corrosive media