unhappy airline customer

APU Mechanical Seals Case Study

A sealing problem causing noxious cabin odor made airline passengers very unhappy. The manufacturer needed a reliable solution. Technetics provided it the first time, thanks to our rigorous and thorough design process.

unhappy airline customer

APU Mechanical Seals Case Study

APU Mechanical Seals Case Study

A Small Issue with Far-Reaching Reputation Implications 

Imagine — You’re leaving for a work trip for a big meeting. The Uber arrives on time, and you have plenty of time to get through security and even grab a coffee. Boarding the plane goes flawlessly, and the flight attendant warmly greets you, letting you know everything is on time. You internally rejoice over the small wins. 

But as soon as you board the plane, you notice a foul smell. You think, ‘it must be from the plane resting; it’ll get better once we take off.’ However, it doesn’t get better. The odor persists the entire flight, and it’s so bad that multiple people have complained. The plane lands, everyone claps and immediately gets on social media to spread the word about the issue. 

You decide to change your return flight to another airline. Now, every time you think of the airline, you think of the rancid smell you endured for five hours on your way to the biggest deal of the year, and you consciously avoid that airline in the coming years.  

This may be an extreme example, but smell and memory are highly connected, so it’s not a far-off scenario. And while the story is fake, the problem was very real for a modern-day airline. The plane had a major sealing problem: the carbon-face seal in the auxiliary power unit was routinely leaking, causing cabin odor. 

Technetics — Turning Problems into Solutions 

 The airline first chose to confront the issue with a Technetics’ competitor to save costs. However, the competitor’s seal didn’t resolve the problem. So, why would this airline trust yet another seal solution provider? It’s simple: Our reliability and quality are unmatched.  

Let us describe our rigorous and thorough solutions process —partnership, design, analysis, and testing — to explain how our solutions deliver the first time, every time.  

Building trust. 

By working directly and intimately with our customers, we focus on forming and maintaining trust throughout the entire process. We remain open, honest, and communicative while finding the perfect solution to meet your needs. 

 Designing the solution. 

We gather any additional information needed to deliver a preliminary design, compliance matrix, and schedule through the design specs you provide. We use the compliance matrix to identify all the requirements and how each will be validated while the plan mitigates any high-risk design requirements. We keep the lines of communication open throughout the design process. Our strict adherence to the schedule ensures we allocate the necessary resources appropriately.  


Analyzing the solution. 

Our rigorous analysis process ensures the ideal outcome every time for our customers. 

We first work to analyze the surrounding components, like operating environments, materials, configuration, and assembly. Using our FEA tool to review seal components, we can predict distortion effects, vibration, and seal face loads.  

 Through the analysis, we may suggest using a metal bellows as a secondary seal, which helps provide a spring force to keep the sealing faces closed during shutdown. This design helps improve stress analysis. We may perform additional testing where necessary to ensure we meet design requirements.  

 Next, we’ll determine if a contacting or non-contacting seal design is appropriate. For non-contacting seals, we use hydrodynamic face seal designs for high-speed applications that need low-pressure differential, like sealing small main-shaft locations. We’ll include lift-off speed and high-altitude condition predictions during this analysis stage. Other variables, such as film thickness and stiffness, are also considered.  

Maintaining flatness is a crucial element of good hydrodynamic performance. We also investigate rotor deflection by ensuring the face seal designs maintain flatness and lubrication while managing deflections. 

Finally, our engineers will analyze the leakage and seal life. While lubrication film is required to maintain face temperature by cooling the interface, it also allows unwanted leakage. This step was essential for this airline’s case since leakage could cause the solution to fail. However, our design toolkit can predict the leakage rate and heat generation, which also helps estimate the seal life. 

Testing the solution. 

After the prototyping phase and we begin building parts, the production and validation phases start. This includes considering the face load versus the drum loading and a vacuum check to determine the quality of the secondary seal.  

Additionally, we make use of four dynamic test rigs to simulate the quality of the solution for your exact scenario, like outburning pressures, speeds, and temperature conditions. Then we conduct another round of leak rate, wear, and face pressure testing.  

Lift Off Seal

Technetics — Your Trusted Engineered Solution Provider. 

For this airline customer, we used the bellows energized hydrodynamic lift-off seal. The seal has performed flawlessly, and the customer’s air cabin odor issue has now been resolved. Because we leveraged the tools and processes described above, we could find a solution the first time. 

With our robust and thorough quality system, we continue to invest in the industry’s demanding requirements and ensure that every expectation is met. Our solution process described above — paired with our fully integrated business software specifically designed for manufacturing and hiring top talent — are just a few reasons we lead the industry in quality and satisfaction.  

At Technetics, we welcome a challenge and love meeting customers’ needs. Ready to tackle your solution together? Contact us today. 

Supporting Space Flight History with the Space Launch System

Supporting Space Flight History with the Space Launch System

Technetics Group is a proud supplier to NASA, Boeing and Aerojet Rocketdyne, and proved instrumental in working with these organizations on the development of NASA’s Space Launch System (SLS). 

The SLS is an advanced, heavy-lift launch vehicle that will send astronauts into deep space and open up the possibility for missions to neighboring planets. The program is enabling humans to travel further into space than ever before and paving the way for new scientific discoveries and knowledge that was once out of reach. 

Technetics has worked closely with program design teams for critical applications for the Core Stage and Upper Stage on the SLS. Specifically, a number of precision sealing solutions and fluid management components were needed for Aerojet Rocketdyne’s RS-25 and RL10 engines to ensure the integrity of the overall system. By working closely with engineers at Boeing and Aerojet Rocketdyne, the Technetics team designed, tested, and implemented custom solutions to solve the critical sealing needs within the engines. Within the Core Stage on the RS-25 engines as well as the Upper Stage on the RL10 engines, solutions included custom metal seals, NAFLEX and K-Port seals, carbon face seals, BELFAB® edge-welded metal bellows, and accumulators. 

Because of the ongoing commitment Technetics has to Boeing and Aerojet Rocketdyne, both organizations have recognized Technetics for their excellent supplier contribution to the SLS program. 

Boeing representatives held a supplier recognition presentation for the Technetics team members, citing outstanding performance in providing hydraulic accumulators and reservoirs for the Thrust Vector Control hydraulic system located within the Core Stage of the rocket. Technetics was one of the first suppliers on the program to have provided all Flight 1 requirements and subsystem test units. 

Aerojet Rocketdyne also recognized Technetics and stated that Technetics “has gone above and beyond to produce quality hardware and support aggressive schedules” and that “Technetics efforts and those of Technetics employees have not gone unnoticed.” To express their appreciation, Aerojet Rocketdyne representatives visited the Technetics Deland, FL facility to present an appreciation letter for the contributions Technetics made in support of Aerojet Rocketdyne’s RS-25 High-Pressure Turbomachinery team. 

The SLS program is ongoing, and Technetics continues to work closely alongside the teams at NASA, Boeing, and Aerojet Rocketdyne to develop custom-engineered sealing and component solutions that provide safety, performance, and reliability while subjected to the harsh environments of deep space. Technetics is honored to be a part of the history-making SLS program and is eagerly awaiting upcoming launches. 


Oil platform


Alternate Energy Solutions, a division of downhole plug manufacturer Thru-Tubing Systems, required a solution to seal caustic gasses on expired wells for a customer in the South Pacific. They reached out to Technetics Group looking for a metal seal solution.  

Technetics Provides Optimal Sealing Solution at Berkley Lab

As a part of its Advanced Light Source Upgrade, Berkley Lab needed a sealing solution for its accumulator ring. After being invited to conduct a metal seal educational presentation, Technetics received the Accumulator Ring BPM application from Berkley Lab.

Machinery in Physics Lab

Technetics Provides Optimal Sealing Solution

Technetics Provides Optimal Sealing Solution

Why Technetics HELICOFLEX® Delta seal was the perfect match for Berkley National Laboratory

The Advanced Light Source is a research facility at Lawrence Berkley National Laboratory (Berkley Lab) working to advance science through its synchrotron light source capabilities. As a part of its Advanced Light Source Upgrade, Berkley Lab needed a sealing solution for its accumulator ring. The upgrade called for a UHV sealing solution appropriate for a synchrotron, with a seal located at the Beam Position Monitor (BPM) housing. The specifications for the application included a leak rate of 1×10-9 cc/sec He atm and temperatures of 25ºC operating and 180ºC bake-out for 1 hour each startup. Furthermore, Berkley Lab required 4 seals for each of the 72 assemblies of the seal, for a total of 288 seals needed for the initial startup of this application.   

Due to the existing relationship between Berkley Lab and Technetics Group as well as Technetics’ involvement for several years in the Advanced Light Source “Kicker Box” assembly, the expertise and industry experience of Technetics was trusted for this application. After being invited to conduct a metal seal educational presentation, Technetics received the Accumulator Ring BPM application from Berkley Lab.  

The HELICOFLEX® DELTA seal was identified as an optimal solution for this application. It incorporates two small ridges, or “Deltas,” on the face of the seal. The high-contact stress in the seal track makes the HELICOFLEX® DELTA seal an excellent choice for ultra-high vacuum applications that require ultra-low Helium leak rates. After the prototype order was received and pump down testing successfully completed, Technetics received additional prototype orders with the expectation of MRO demands every 2 years.  

SLS Case Study

SLS Case Study

Technetics Group is a proud supplier to NASA, Boeing and Aerojet Rocketdyne, and proved instrumental in working with these organizations on the development of NASA’s Space Launch System (SLS).


SLS Case Study

Qualiseal® Circumferential Seals

Qualiseal® – Circumferential Seal Application: Military Aircraft

Circumferential Seal Application: Military Aircraft

The control valve in a military aircraft had a controlled gap circumferential seal with a carbon steel composite ring assembly.  High wear and carbon ring deterioration resulted in shortened seal life.

Operating Conditions

  • High temperature (1,125°F)
  • Pressure (660 psid)

Determining Cause and Failure Modes

  • High-temperature carbon grade oxidizing due to high temperature

Technetics Qualiseal® Technologies Solution

  • Designed a controlled gap circumferential seal utilizing a solid silicon carbide ring, improving temperature rating up to 2,500°F
  • Silicon carbide ring increased seal pressure rating based on FEA generated stress distribution

Gearbox seal

Qualiseal® – Mating Ring Solution: Hydraulic Pump

Mating Ring Solution: Hydraulic Pump

An aerospace OEM historically purchased an inexpensive mating ring to pair with a precision carbon face seal in a hydraulic pump.  The supplier was capable of achieving flatness to 6 HLB.   The buyer was satisfied because the mating ring met the design requirements at a low cost.

Operating Process

  • After receiving the mating rings, the OEM inspected 100% of them using a laser interferometer to ensure sufficient flatness.
  • 80% of the mating rings needed to be re-lapped and re-inspected before they could be used even though they were built to spec.
  • The total cost of the final product was significantly greater than the amount on the purchase order

Technetics Qualiseal® Technologies Solution

  • Technetics Qualiseal® Technologies manufactured mating rings to a standard above the customer’s design requirements, achieving flatness to 3 HLB or better.
  • Inspected utilizing QT’s laser interferometer and delivered ready-to-use products to the customer.
  • The customer recognized savings in the “total cost” of the product and also reduced the required inspection staff by two.