Are You Using Counterfeit Pirated AODD Pump Parts ?

August 2, 2022

It's important for you to know that you are using genuine OEM parts in your Wilden pumps to optimize their performance and ensure safety.  Here's how to avoid the costly mistake of purchasing counterfeit pirated parts.

Every genuine Wilden® Spare Part Kit will be shipped in a sealed package with the company name in the traditional font and color on the cardboard backing, while individual replacement parts will be shipped in marked bags.

View Wilden Parts here.

Wilden Aftermarket Parts

A sure indicator that a part has been pirated is its arrival in atypical packaging, such as valve balls that are delivered in simple plastic bags with the name and part number written in marker.

Wilden Aftermarket Parts 2

John also recorded this as a podcast for Pumps and Systems magazine. Listen to the Podcast here.


AODD Pump Competition

When Jim Wilden invented the air-operated double-diaphragm (AODD) pumping principle in 1955, it’s no exaggeration to say that he also created the diaphragm pump industry. As the creator of AODD pump technology, Wilden established a standard for highly engineered machines that still exists. This is a standard that competitors – whether legitimate or not – have tried to copy with varying degrees of success.


The legitimate competitors have driven Wilden to even further product innovation, resulting in AODD pump models that are truly cutting edge and optimize pumping operations, whether they involve oil-and- gas recovery or chemical processing, pharmaceutical development or mining.


However, the illegitimate competition creates cause for concern.


In recent years, a number of “knockoff” companies have entered the market. These companies are pirating pump components and accessories and selling them to unsuspecting customers as genuine Wilden parts. This report will offer a “Let the buyer beware” look at how these companies are attempting to capitalize on Wilden’s good name and reputation, and how users can identify a pirated part and avoid the potentially costly mistake of purchasing them.

Why do you need OEM Genuine Wilden Parts?

Jim Wilden’s AODD pump design is known for it's simplicity of operation. Despite that, Wilden AODD pumps require a series of parts and components to work in perfect harmony – and meet well-established standards for operation – in order for the pump to perform as expected.

The list of AODD pump parts that the user must be familiar with include the pump body (metal or plastic), diaphragms, pistons, valve balls, valve seats, valve seat O-rings and the Air Distribution System (ADS). Within the ADS, or air motor, the center block, air valve and air control spool are the most significant parts.

However, as the design of AODD pumps has matured, and the list of industries in which they are used has expanded, it is no longer possible to just order, for instance, a “diaphragm.” Different designs and materials of construction have increased the available options while meeting the needs of the new applications where the pumps are used. This has also increased the complexity of the ordering and supply process. The result is that AODD pump users must be finely tuned into the needs of their machines – increasing the importance in using genuine parts when outfitting their pumps.

As mentioned, Wilden AODD pumps only operate at peak performance when the proper original equipment manufactured (OEM) or approved components are used. Failure to use the proper components can result in:

  • Voided warranty: If the pump fails and is found to be outfitted with a knockoff part rather than a genuine OEM part, the warranty can be voided. This can result in the user footing the bill for any repairs or the purchase of a new pump.
  • Lower flow rates: Satisfying demanding production schedules is a front-of-mind concern for all manufacturers and components that may not meet strict design standards will not perform as expected. This can mean minimized production rates, along with higher operational costs that are brought on by the need for increased operational time.
  • More frequent breakdowns: Again, pirated parts are not subject to OEM quality-control standards and will be more susceptible to breakdowns that can lead to increased downtime, maintenance costs and repair costs
  • Reduced operational safety: Using a non-OE part can jeopardize chemical compatibility and even worker safety. In other words, you just can’t be sure what you’re actually getting if it isn’t a genuine part – and you shouldn’t be willing to take that risk.

Pirated Parts - the Telltale Signs

Unfortunately, the entry of pirated parts into the AODD pump market has become a fact of life. While these parts may try to capitalize on the Wilden reputation, they are obviously inferior and unable to deliver OEM level performance. Knowing that, these unscrupulous suppliers attempt to “trick” users by mimicking the brand or referencing specific part names, numbers and performance curves.

There are a number of ways, though, that these pirated parts can be recognized:

  • Part numbers that are not typical for the brand The most common example of this phenomenon is a part number that begins with a letter when, in reality, the part number is strictly numerical. For instance, a typical part number for a Wilden diaphragm may be 08-1022-58. However, there are counterfeit replacement models now available that claim to be genuinely Wilden that have a part number that begins N08 or PF08, with the “N” and “PF” representing the first letter(s) of the knockoff company’s name.
  • Missing critical identification stamps: Diaphragms and most other parts made by Wilden always have a "Manufacturing Date Stamp" clearly shown on the part. These stamps identify the Wilden brand and part number, along with indicating the month and year in which the part was manufactured. Wilden Aftermarket Parts 3 Side By Side

    An obvious differentiator between genuine and pirated parts is the presence of a "Manufacturing Date Stamp." Genuine parts will have the date the part was manufactured stamped on the exterior, along with the brand name and proper part number, while pirated parts will not.

  • Parts shipped in non-traditional or atypical packaging: All genuine Wilden Spare Part Kits are packaged on a sealed cardboard sheet featuring the Wilden name. Any replacement parts ordered outside of Wilden's parts kits are shipped in a plastic bag with the Wilden name, notation of "Genuine Wilden Parts" and facility address/contact information printed on the bag with the part number and quantity indicated. Some brazen piraters are shipping individual parts in simple plastic bags with the part name and number written with a marker and nothing else. Receiving parts in this manner should raise red flags. Wilden has taken many years to cultivate and refine its unique logo and color scheme. So, if a set of replacement valve balls arrives in a package where “Wilden” is written in metallic blue in an Olde English font, there’s a good chance the parts have been pirated.
  • Parts that claim to be constructed of a certain material, but may not be: It’s easy for a counterfeiter to say that a diaphragm is made of Wil-Flex™ – and to the untrained eye, that claim may be hard to refute. Wilden diaphragms come in a variety of blends of different materials. Wilden has extensively tested the blend that works best in its pumps to maximize life, limit startup pressure and ensure easy installation. Pirated parts won't necessarily use the same material blends that Wilden has proven to be best for its pumps. Also keep in mind, though, that a true Wilden diaphragm of any type of construction will have the Wilden logo stamped on the back along with the part number, while the pirated part will not. All of this is important because operating a pump in an application that requires Wil-Flex when the diaphragm is, in fact, not Wil-Flex can lead to increased downtime, maintenance costs and replacement costs, as well as a reduced level of safety.
  • Fake documentation: Before any products are released, Wilden carefully field and factory tests them, and then publishes the performance data in its manuals that are shipped with each part. Some pirates attempt to duplicate Wilden's manuals, right down to the use of matching font styles and flow-curve formats. In fact, some counterfeiters will literally "cut and paste" Wilden's manual graphics into their own IOMs instead of conducting legitimate tests.

Still, it’s likely that some of the more sophisticated counterfeiters may be able to replicate the look and feel of Wilden packaging and part-number nomenclature. This will make it more difficult to readily identify a pirated part. In this case, the user will have to pay close attention to the pump’s performance after any replacement parts have been installed.

Simply put, the machine will not be able to deliver the level of performance that is expected when outfitted with a non-OEM part.

It pays at this point to reiterate again the dangers that can be created for the operator if Wilden AODD pumps are not equipped with genuine OEM parts. Foremost are breakdowns or malfunctions that can compromise the safety of the operation, site personnel and technicians, and surrounding communities and the environment. This is a risk that should not be taken in the name of saving a few dollars through the use of non-standard knockoff parts – especially if it means that a warranty will be voided.

Wilden Aftermarket Parts 4 Counterfeit Curve

The manufacturers of pirated parts will oftentimes create a "cut and paste" reproduction of the part's performance information that comes straight from the manual of the original manufacturer. In this example, there is no real discernible difference between the flow curve for JDA's pirated parts, on the left, and the original version from Wilden, on the right, while their actual performance will vary greatly.

Wilden Aftermarket Parts 6

Despite this invoice claiming that the ordered diaphragm is made of Wil-Flex®, you can look no further than the non-Wilden part number of N04-1010-58 to know it is pirated. Genuine Wilden® part numbers start with a number between 0 and 9; they do not begin with a letter as shown in this example.

Wilden Aftermarket Parts 7

Genuine Wilden® replacement parts won't be packaged with a cardboard backing, but will be packed in a bag with the Wilden name, the "Genuine Wilden Parts" notation and address embossed on the front with the part nuWilden Aftermarket Parts 5 Wilden Curvember and quantity indicated.


Imitation may be the highest form of flattery, but pirated parts will always be the bane of legitimate operators in any industry. Through a combination of awareness and due diligence, the users of Wilden AODD pumps can take the sting out of the knockoff-parts market, and ensure the safe, reliable and efficient operation of their equipment. The overriding lesson here is simple: Always buy genuine parts either directly from the manufacturer or from an authorized distributor or sales representative that is listed on the manufacturer’s website.

This article was written by John Wallace, the Sales Director US & Canada, Diaphragm Group for Wilden® and PSG®.