Bridging the Gap with Case Studies and Real-World Results
Garlock’s gaskets offer a tolerance for poor conditions and variation of installation practices while maintaining a seal.
By Jim Drago, Principal Application Engineer - Garlock
Click here to read the original article in Processing Magazine.
I heard this quote during a test standards committee working session: “Once is chance, twice is verified, and three times is validated.”
It’s an adaptation of a line spoken by James Bond in Ian Fleming’s novel Goldfinger, “Once is happenstance. Twice is coincidence. Three times is enemy action.”
In the realm of qualifying new industrial products as fit for service, the enemy takes the form of imagined and unimagined variables when applied in the field. Multiple field evaluations verify and validate performance and are necessary steps for new product development and introduction.
In the test lab, we are gratified when a new product performs successfully. Often, this outlook is premature. Repetitive testing usually reveals failures, successes and unexplained outliers. Once we make it through a series of successful trials, we begin to feel confident. At that stage, although we have confidence in the product’s performance; we also acknowledge that our confidence is based on performance in a controlled laboratory environment. We lack the experiences of real-world handling and use — the place where we are no longer in control.
The Importance of Field Testing
End-users expose flange gasket sealing materials to many direct variables latent in installation practices, equipment anomalies, product storage, handling during transport to the flange location and more. Indirect variables include the user company’s safety culture, view on time efficiencies to complete tasks, staffing levels, financial constraints and so forth. This is the world the gasket lives in. In the field, it must be forgiving and robust enough to work repeatedly despite the variables. During the product development process, the only way to find this out is through early adopters willing to evaluate and report their experiences.
Unlike the consumer products markets, process industries are cautious about being the first to trial a new product. Industrial users want assurance beyond promises of superior performance and operational savings. In other words, they say, “Show me.”
Addressing the Need for Solutions
At Garlock, our mission is to function as a problem solver for existing and even future challenges within the industries we serve. For example, the recent development of our GYLON EPIX® line of products was precisely that — a response to a set of specific challenges encountered across industries. In fact, the product development roadmap stemmed from a processing industry market study that revealed these chief concerns among gasket users:
- Anxiety that gaskets haven’t been compressed enough
- Gasket creep and the need to re-torque flange joints
- Desire for a gasket that seals with lower compressive load
- Frustration with the human variable of flange-gasket joint assembly
- Disappointment caused by leaking flange-gasket joints
GYLON EPIX® was intended to alleviate these concerns by focusing on creating a gasket that has forgiveness — that is, has a tolerance for poor flange conditions and variation of installation practices while maintaining a seal. Field case studies taught the developers how to hone the application guidance for reliable service. GYLON EPIX® was introduced to the market in January of 2018. Prior to introduction, seven field evaluations had either been launched or completed. These early adopters paved the way for more field evaluations and more documented experiences.
To date, 66 field evaluations have been documented, over 20 of which have been published on Garlock.com.
Real-World Examples
Case 1 – Glass-and PTFE-Lined Flanges and Toxic Media
An agrochemical manufacturer’s process had a steel glass-lined plate and frame heat exchanger with cyanogen chloride, water and hydrochloric acid at 140°F (60°C) and vacuum of -3 psig (-0.2 bar-g). The pipe system mating with the heat exchanger is steel PTFE-coated pipe, so the pipe joints had one glass-lined flange and one PTFE-coated. When toxic media leaked, personnel were at risk to be injured. Alarms warned personnel that the area was unsafe, and work came to a halt. Expanded PTFE lasted only 3 months. Rubber gaskets made of EPDM and FKM sealed well, but would last no more than 6 months. Three challenges were identified: First, flange joints with dissimilar materials (one glass-lined flange, and another PTFE-coated). Second, since the media is toxic, leaks of any kind would cause serious, potentially fatal, harm to workers and interrupt production. Third, vacuum — the popular idiom “nature abhors a vacuum,” highlights the difficulty of sealing a vacuum.
Glass- and PTFE-lined flanges cannot be tightened in an uncontrolled manner. Too little, and the toxic media escapes harming personnel, setting off alarms and stopping production. Too much, and the flanges flex, glass cracks, the PTFE coating thins and a toxic leak follows. The flanges cannot be subjected to unchecked tightening, so bolt torque and resulting compressive stress on the gasket must be minimized and optimized. Enough load should initiate and maintain a seal while not over-tightening. The lower compression of the gasket caused gasket creep, requiring frequent retightening.
Garlock worked with the customer to understand their unique challenges and recommended GYLON EPIX® Style 3504 EPX. This solution was tested with the glass-lined flange and the PTFE-coated flange. The result was impressive. GYLON EPIX® Style 3504 EPX lasted more than a year, prevented leaks and did not require retightening. No imprints of the gasket’s raised profile appeared on the glass- or PTFE-lined flanges. The facility then converted all the heat exchanger’s gaskets to GYLON EPIX®.
Case 2 - Multinational Provider of Pulp and Paper Products
A flange joint was subject to sodium lignosulfonate at temperature 176°F (80°C) under vacuum. The flanges were custom-plate steel using 12 – M16 (approximately 5/8 of an inch) bolts and full-face gaskets measuring 300mm x 455mm (11.8 inches x 17.9inches) and 320mm x 455mm (12.6 inches x 17.9 inches)
The customer specializes in processing wood and paper pulp for paper and bio-refinery applications. The customer was experiencing flange leakage on a rotary valve that was such a problem, it was named “The Traumatizer.” The constant failure of the gaskets allowed the ingress of air into the system, which reacted with the sodium lignosulfonate powder and solidified it, ruining the batch and rendering it unusable. The gaskets had to be routinely changed every two to three weeks to maintain system integrity and minimize product losses.
The customer installed the first GYLON EPIX®; 3500 in June 2019. It was still in operation and successfully sealing in January 2020 — far exceeding the life of previous gaskets. Thanks to the success, plant maintenance is planning to install GYLON EPIX® in more rotary valve flange connections and steam applications.
Case 3 – Storage Tank Manway
A global oil and gas producer was having trouble sealing an old and pitted, 1930s-era oval manway flange on a storage tank. These nonstandard flanges are difficult and costly to machine repair or replace. Finding a reliable sealing solution for the tank farm was imperative. Initially, a compressed fiber sheet was used, but they could not maintain a seal due to the pitted surface condition. Leaks followed.
The media being sealed was butane at 65 psig and ambient temperatures, using A193 Grade B7 studs. Butane is an EPA-regulated, volatile organic compound (VOC) and leaks on a ppm level can lead to compliance violations. The severe pitting on the flange faces was the biggest hurdle to achieving a perfect seal. Replacing or repairing the flange was costly and would take the tank offline, disrupting operations and adding more costs. Finding a gasket suited for the less-than-ideal flange conditions was the best path forward.
The manway flanges are flat, obround 22.5 inches x 34.5 inches, ambient temperature and 65 psig. The customer worked with Garlock’s engineering team to install GYLON EPIX® Style 3504. Torque values were provided to attain 3600 psi gasket stress. The gasket has been in service without leaks for more than a year. The EPIX®-raised, hexagonal surface profile was able to easily conform to the imperfect flange surfaces. The plant avoided costly repairs, downtime and EPA non-compliance events.
Answering the Call
As problem solvers within the industries we serve, we find it fulfilling to answer the call in providing lasting solutions for our industry partners’ greatest challenges. The entire product development process—from field evaluation to ideation, prototyping to testing and beyond—is one we take great pride in, and our GYLON EPIX® line of gaskets is another example of our commitment to safety, longevity and greater productivity for our customers around the world.
Jim Drago is a principal application engineer at Garlock. He graduated from Clarkson University with a BS in Mechanical Engineering and has been a registered professional engineer since 1989. Drago’s experience spans over 45 years in the areas of power, maintenance and fluid sealing for the process industries and dielectric materials technology.