The Waterjet Industry’s Confusing World of Redundant Names

Navigating the terminology within the waterjet industry can be a frustrating task.

With various companies, countries, and individuals having different names for the same items, it’s easy to become perplexed. In this blog, we’ll explore some of the commonly used redundant names in the waterjet industry and shed light on the confusion they can cause.

Plunger Seals, High-Pressure Seals and Dynamic Seals

When it comes to items used in sealing the plunger side of the high-pressure cylinder, you may come across different terms like plunger seals, high-pressure seals, inner seals or dynamic seals. Don’t be alarmed; they all refer to the assembly that seals the space between the high-pressure cylinder and the ceramic plunger. Despite the varied names, their purpose is the same even though their appearance and design may change from one pump brand to another.

Orifices and Nozzles

Orifice and nozzles are terms used interchangeably to describe a variety of items that can be quite different from one another, but all have the same function, giving us a focused high-pressure cutting stream.

A couple more terms you hear talked about a lot in the industry are, sapphire and ruby orifices. These two terms are also used interchangeably and for good reason. Interestingly, these two items are usually made of hard, lab-grown materials which are encased in a stainless-steel setting with the difference being only the color. That’s right, despite being different colors, they are both made of the exact same material and serve the exact same purpose. So, in this case, we have an assembly that is called two names which incorporates a hard gem that is the same material but is also called two different names based on the color of the material.

Cutting Heads, Abrasive Heads and Mixing Chambers

At the end of a pneumatic valve, where high-pressure water and garnet first mix, you’ll find cutting heads, abrasive heads or mixing chambers. Don’t let the different names fool you—they all perform the same function.

Focusing Tubes, Abrasive Nozzles, and Mixing Tubes

Prepare for more name confusion… Focusing tubes, abrasive nozzles and mixing tubes are all different terms used to describe the same carbide item. They play a vital role in mixing and focusing a high-pressure stream of water and garnet used in cutting extra hard materials like granite and metal. They can be found affixed to the end of the previously mentioned cutting heads.

Sealing Head and Check Valve Body

A sealing head and a check valve body might sound like separate items, but in fact they are the same in function. Different manufacturers might use different terms for this item, but their functionality is the same, holding a series of independent check valves, which are designed to control the direction of high-pressure water. This would prevent the high-pressure water from either reentering the high-pressure cylinder once it leaves, or high-pressure water from entering the low-pressure inlet water.

Without check valves, the system would simply pump water back and forth between its two ends.

Cylinder Heads, End Closure Blocks, and End Bell Housings

To seal the ends of the hydraulic drive on intensifier pumps, you’ll encounter cylinder heads, end closure blocks or end bell housings. Despite the multiple names, these items serve the same purpose—they seal the ends of the hydraulic cylinder so that the energy generated by the hydraulic drive can be used to intensify the water on the high-pressure side of the intensifier.

Check Valve Housings and Cylinder Nuts

To seal the static end of the high-pressure cylinder, you may hear the terms check valve housings and cylinder nuts. Don’t get confused; they refer to the same item used to hold the check valve in place on the end of the high-pressure cylinder.

Hydraulic Piston or Hydraulic Biscuit

The hydraulic unit on intensifier pumps features the hydraulic piston or hydraulic biscuit. Yes, they are different terms for the same item—a crucial component that reciprocates inside the hydraulic cylinder to assist in pressurizing the hydraulic system.

Elbows and 90-Degree Fittings

Even something as simple as an elbow can be subject to naming variations. In the waterjet system, an elbow can also be referred to as a 90-degree fitting used for plumbing high-pressure water to exit the system.

Shift Sensor and Proximity Switch

Have you ever heard someone mention changing a shift sensor or a proximity switch? Well, they are actually referring to the same thing. This component is used to electronically reverse the reciprocating hydraulic piston from one end of the hydraulic unit to another as the system intensifies water within the high-pressure cylinders.

Rod Seals and Plunger Seals

When it comes to sealing the outside diameter of the carbide or ceramic plunger, you might come across the terms rod seals and plunger seals. Fear not, for they are just two names for the same item. These seals prevent pressurized hydraulic oil from escaping the hydraulic drive. Further complicating matters, the term plunger seals are also sometimes used to describe the high-pressure seals which seal the high-pressure cylinder against the plunger as the system generates cutting water. These seals were the first items mentioned in this article.

Accumulator or Attenuator

This large pressure vessel of charged water plays a crucial role in mitigating pressure fluctuations in the system and reducing striations on the surface of the material being cut. These terms may be easier to remember than others since they both begin with the letter A and are very similar in pronunciation and length.


These examples are just the tip of the iceberg when it comes to the redundant names found in the waterjet industry. It’s important to keep in mind that terminology can vary from company to company, country to country, and person to person. So, next time you find yourself immersed in waterjet jargon, take a deep breath and embrace the diverse array of names used for the same items. And always remember, even the most confusing terms can bring a smile to your face, like the infamous “thingamajig” or the “thing that looks like a top hat” 🙂 Happy Waterjetting!

About the Author

Waterjet Systems International has been a manufacturer of premium high-pressure and ultra high-pressure waterjet pumps and replacement parts for over 30 years. WSI manufactures its own line of proprietary waterjet pumps and cutting heads along with a premium line of KMT Waterjet, Flow Waterjet, and H2OJet compatible replacement parts.

WSI specializes in servicing the worldwide automotive, aerospace, and metal industries, but prides itself in providing the highest level of support, service, and products to its OEM’s, distributors, and end users regardless of size, industry, or purchasing power.