Application of Wilden T15 diaphragm pump in the marine industry: durability is the last word

When selecting marine equipment, why is the pump the key?

Anyone who works on a ship knows that equipment failure is the most troublesome thing. Especially the pumps - the

 sewage tank needs to be pumped, the bilge water needs to be drained, the oil residue needs to be treated, and the

 ballast water needs to be adjusted. If a pump is lying down, the whole ship will be affected. Seawater corrosion, oily

 bilge water, 24-hour continuous operation, insufficient supply of spare parts... these are real problems that shipowners 

and engine crews face every day.

In the past few years, I have noticed in communicating with several ocean-going ships and offshore engineering ships

 that Wilden's T15 plastic pneumatic diaphragm pump appears more and more frequently on ships. It’s not that this

 pump is new or fancy, but it’s because it “doesn’t have any fluff” – it’s solid, durable, and easy to maintain.

What is the origin of T15?

The Wilden brand is familiar to those who engage in diaphragm pump manufacturing. An old American pneumatic pump 

manufacturer with rich technical accumulation, T15 is a plastic pump in its 15 mm diameter series. Compared with metal

 pumps, it weighs a lot less - it weighs 20 to 30 kilograms and can be carried by an adult without a crane or forklift. It is

 especially useful in narrow places like aircraft cabins.

The material is polypropylene or PVDF shell, which is not afraid of sea water, salt water, weak acid and alkali, and oily sewage.

 Non-metallic material means no worries about rust – a huge advantage for marine equipment.

A real case of a bulk carrier

Last autumn, a domestic shipping company, a handy bulk carrier running the Southeast Asia-Australia route, replaced a 

five-year-old metal screw pump in the engine room with a  Wilden T15 during ship repair in Zhoushan. The ship's bilge 

water system always had problems before, and the oil content in the sewage was unstable. The mechanical seals of the 

pumps had to be replaced every three months. The chief engineer had to order spare parts in advance every time he visited 

Singapore, which was very troublesome.

After changing to T15, the most obvious changes are three points:

First, there is no need to worry about seal leakage. The pneumatic diaphragm pump does not have a rotating shaft seal. 

It relies on the left and right chambers to alternately compress air and the diaphragm to move back and forth to transport 

the medium. The chief engineer on board told me that oil leakage from the shaft seal of the screw pump was a common 

occurrence in the past, and the engine room floor was always greasy. After the T15 was installed, the floor was dry and dry,

 and even wiping it down once a day was too much.

The second is not to pick the medium or the working conditions. The bilge water is sometimes clear and sometimes muddy, 

and occasionally a mixture of residual oil and sediment will be pumped up. The T15 has a wide flow channel and does not have 

a tightly matched rotor-stator pair. Small particles of three to five millimeters can pass directly without fear of blockage. The ship

 has also tried to use it to temporarily pump out sewage with a relatively high oil concentration, and it still works.

Third, dry rotation does not burn the pump. This is the inherent benefit of a pneumatic diaphragm pump - even if the suction 

port is evacuated, the pump is still inflating, and the diaphragm still reciprocates, and will not "burn out" and damage the 

mechanical seal like a centrifugal pump. The on-duty personnel on board do not need to keep an eye on the liquid level all the

 time, and the risk of misoperation is much lower.

What does the maintenance guy say?

I had a special chat with the chief engineer of that ship (everyone called him Lao Chen). Lao Chen has been running boats for

 more than 20 years and has seen more pumps than eaten salt. He said something quite honest:

"In the past, if a pump broke, it would have to be dismantled. After disassembly, the gears, bearings, and machine seals had to 

be aligned with the center line. A repairman might not be able to put them back together after a day's work. The T15 has a simple

 structure, with only the ball, diaphragm, and O-ring. Even if the diaphragm is broken, two people can replace it in half an hour, and

 no special tools are needed."

Lao Chen also mentioned a detail: the spare parts warehouse on the ship no longer needs to stock a bunch of things for this pump.

 A few diaphragms and valve balls are enough for a whole year. For ocean-going ships, spare parts are small in size and light in weight,

 which means that storage and logistics costs are reduced.

Can the economic accounts be settled?

Some people may ask, if the pneumatic diaphragm pump is not as efficient as a centrifugal pump, will it suffer in terms of energy 

consumption?

It depends on how you calculate it. The energy consumption of the T15 is indeed a little higher than that of a centrifugal pump

of the same caliber, but there is usually no shortage of compressed air on board - most ocean-going ships are equipped with

 independent deck/engine room air systems, and the air source is readily available. There is no need for additional motors, cables,

 control boxes and explosion-proof junction boxes, which saves initial installation costs.

What’s more critical is the full life cycle cost. The price of the T15 machine is medium, but the accessories are cheap, repair work

 is short, and downtime is minimal. Based on the situation of Lao Chen's ship, the cost of repairing spare parts in one year has been 

reduced by about 40% compared with the original cost, and the operational delays caused by unplanned pump shutdowns have

 basically been eliminated.

Which shipboard scenes are particularly suitable for T15?

Based on actual usage feedback and product features, these scenarios are particularly cost-effective:

Bilge water transportation: The medium composition is complex, often containing particles and oil-water mixture. T15 has obvious 

advantages in corrosion resistance and passability.

Oil residue/sewage oil and water transfer: viscosity changes greatly, pneumatic pump outlet pressure is adjustable, and flow rate is 

easy to control

Ballast water tank drainage: the pump is required to work intermittently and have strong self-priming ability (T15 dry self-priming 

can reach about 6 meters)

Chemical tank tank washing water treatment: T15 made of PVDF has excellent chemical resistance and is suitable for acid and alkali

 media

Material transfer between shore and ship: light and mobile, with four handles, people on board can move it easily

Several things to note

Of course, no device is perfect. There are a few points to note when using T15 on a boat:

The quality of the air source must pass the standard - the compressed air contains too much water and oil, which will affect the 

service life of the air valve. Installing a simple air filter + oil mist on the boat can solve the problem.

The noise is slightly louder than the motor pump - the pneumatic exhaust will be a bit noisy, but the T15's exhaust muffler is done

 well enough to not be unbearable.

Limited flow rate - 15mm diameter, maximum flow rate is about 150 liters/minute, suitable for small and medium flow scenarios. 

Rapid drainage of large cabins is not its strong point.

Finally, tell the truth

Wilden T15 is not the kind of artifact that can do anything in the world. It is a pragmatic, durable and easy-to-serve pump. In the 

shipping industry, which has high reliability requirements, limited maintenance conditions, and highly corrosive media, it happens

 to be stuck where it is most needed.

On several ships I have contacted, from installation to follow-up visits, the feedback from the engineering staff on T15 has been 

relatively positive. There is no "surprise" or "fright" - using this device, feeling nothing is the best feeling.

If the ship you manage happens to have needs for bilge water transportation, sewage oil and water transfer, or chemical transfer, 

and you don’t want to disassemble and repair the pump every three days, you might as well find an opportunity to try T15. It may 

not be the cheapest, but it is most likely the worry-free choice.