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Heisman Winner… and Rubber Salesman?

Jay Berwanger, Heisman Winner.

To football aficionados, Jay Berwanger is well-known as the winner of the first Heisman Trophy and the first player chosen during the National Football League’s first draft. Less well-known is that he achieved his athletic successes at the University of Chicago, a school now more closely associated with Nobel prizes than big-time football. Berwanger, a halfback, played for the University of Chicago Maroons at a time when Chicago was a member of the Big Ten Conference–before Robert Hutchins, the University’s president, famously abolished varsity football in 1939.

Even in an era before football teams were divided up into offensive and defensive squads, Berwanger was renowned for his versatility.

Berwanger PosingIn 23 varsity games in three seasons with the Maroons, he scored 22 touchdowns and kicked 20 extra points. He gained 1,839 yards on 439 rushes for a 4.2 average. As a sophomore, he played 60 minutes of every Big Ten conference game and was voted the team’s MVP. During his collegiate career he returned 54 kickoffs and punts for a 31.8-yard average, completed 50 of 146 passes for 921 yards and caught 12 passes himself for 189 yards. He averaged 38 yards on 233 punts and 46.3 yards on 34 kickoffs. He once recorded 14 tackles playing linebacker in one half.

In 1935, the Chicago Tribune awarded Berwanger the Silver Football for Most Valuable Player in the Big Ten. His coach, Clark Shaughnessy, called him “every football coach’s dream player. You can say anything superlative about him, and I’ll double it.” Of the 107 opposing team players he faced during his senior year, 104 said the six-foot, 195-pound Berwanger was the best halfback they had ever seen.

In November of 1935, Berwanger received a telegram from Manhattan’s Downtown Athletic Club, informing him that he had won a trophy for being the “most valuable football player east of the Mississippi,” as well as a trip for two to New York. “It wasn’t really a big deal when I got it,” Berwanger recalled in 1985. “No one at school said anything to me about winning it other than a few congratulations. I was more excited about the trip than the trophy because it was my first flight.” The prize was later renamed the John W. Heisman Memorial Trophy, after the club’s athletic director, the following year.

He was born John Jay Berwanger in 1914 in Dubuque, Iowa. In high school, he excelled at wrestling and track as well as football, winning renown as an all-state halfback. After graduation, Iowa, Michigan, Minnesota, and Purdue all tried to recruit him, but he opted for Chicago, which had offered only a basic tuition scholarship of $300 a year. To meet his expenses, Berwanger waited tables, cleaned the gymnasium, fixed leaky toilets, and operated elevators. “Times were tough then,” he said. “I wanted to attend a school that would give me a first-rate education in business, without special treatment, so that I would be prepared when opportunities were certain to return.”

During his freshman year, Berwanger was coached by the legendary Amos Alonzo Stagg, who helped define the game of football as we see it today. Berwanger’s first year at Chicago was Stagg’s last. As well as captain of the football team, Berwanger was captain of the track team, senior class president, and head of his fraternity, Psi Upsilon.

Berwanger was the only Heisman recipient who was ever tackled by a future president of the United States–Gerald Ford, during a 1934 game between Chicago and Michigan. “When I tackled Jay in the second quarter, I ended up with a bloody cut and I still have the scar to prove it,” President Ford recalled. “Jay was most deserving of his Heisman Trophy. He could do it all. He was an outstanding runner as well a passer, he could kick, punt, and make field goals–and in those days the ball was round so it was much harder to throw. He and I had met several times in the years since that game and I remember him fondly as one of the greatest athletes I’ve known.”

Berwanger was also the first player chosen for the National Football League during its first-ever draft in 1936. After the Philadelphia Eagles signed him, Coach George Halas of the Chicago Bears acquired the signing rights. But when Berwanger asked for $25,000 over two years, Halas decided that was too much money, so Berwanger took a job as a foam-rubber salesman.

Jay Berwanger, Rubber Salesman and Lieutenant Commander

Shortly after starting his job as a rubber salesman, Berwanger enrolled in the Navy’s flight training program and became a Naval officer during World War II. He eventually earned the rank of lieutenant commander.

After the war, Jay Berwanger founded Jay Berwanger, Inc., a manufacturers’ sales agency specializing in rubber, plastic, urethane and other elastomeric materials for car doors, trunks, and farm machinery. His company established a guiding philosophy to create superior value for all customers and principals through dedicated service and by providing integrated solutions to customers’ applications.  Jay sold his company in the early 1990’s when its annual revenue was $30 million.

Post-Heisman and Rubber

Berwanger Heisman and FootballBerwanger was never sure what to do with his Heisman Trophy, which was too wide for a mantelpiece and too large for a coffee table. For years, his Aunt Gussie used it as a doorstop. Berwanger eventually gave the trophy to the University of Chicago where it is on display.

In 1954, Berwanger was inducted into the College Football Hall of Fame. In 1989, he was included on Sports Illustrated’s 25-year anniversary All-America team, which honored players whose accomplishments extended beyond the football field.

Berwanger died in the summer of 2002 and is survived by three children, three step-children, 20 grandchildren, and 13 great-grandchildren.


Information for this article was gathered from Sports Illustrated’s vault, the University of Chicago, and New York Times.

Gallagher has no relationship or partnership with Jay Berwanger Inc. If you liked this article or have an idea about another topic, please let us know!

The Proper Use of Lubrication and its Success with Bolted Flange Connections

Extra energy transmitted can produce larger sealing stress on the gasket.

The bolt as a screw is one of the six simple machines. A simple machine magnifies or changes the direction of an input force. By means of mechanical advantage, a bolt can dramatically increase its input force. Take for example an 8-bolt flange with 3/4-inch diameter bolts. By manual effort alone, a person can easily develop a total bolt load of over 110 tons. This article explains the mechanics by which the mechanical advantage is possible and then draws attention to how friction can deteriorate the end effect of a bolt’s mechanical advantage.

The means by which a bolt can greatly magnify input load is by leverage. One source of this leverage is afforded by the geometry of the bolt. The other is the leverage from a tightening tool—in this example, a torque wrench. To illustrate the mechanics of a screw thread, consider a 3/4-inch diameter, Unified Course (UNC), A193 B7 bolt with a yield strength of 105,000 pounds per square inch (Image 2 identifies the geometrical characteristics of a bolt that create leverage).

The pitch circle is defined as the circle that passes through the pitch line of the threads. The pitch line is the theoretical point of contact between the male and female threads.

Threads of a bolt
Image 1. The threads of a bolt essentially form an inclined plane

The pitch is the distance between thread crests, and is the axial distance the bolt travels in a single 360-degree turn. The threads of a bolt essentially form an inclined plane wrapped around the minor diameter of the bolt (Image 1).

The horizontal distance (pitch circle) traveled divided by the vertical distance traveled (pitch) is the mechanical advantage of the bolt geometry.

For the 3/4-inch bolt, the values for the pitch (P), pitch circle diameter (Pd) and pitch circle circumference (Pcc) take on the following values: 0.10 inch, 0.6850 inch and 2.152 inch, respectively. The helix angle becomes Tan-1 (P/Pcc) = 0.266 degrees.

Image 2. Geometrical characteristics of a bolt that creates leverage

The pure mechanical advantage of the threads, designated as MAt, is the horizontal distance traveled divided by the vertical distance traveled, in Image 2. Its value becomes MAt = 2.152 inch/0.10 inch = 21.52:1. Relative to the pitch circle, 1 pound of input force would create almost 22 pounds of output force.

Now evaluate the additional mechanical advantage of a torque wrench. Presume the use of a 3/4-inch drive, 48-inch-long torque wrench with an effective length (based on the pull-point of a person’s hand) of 44 inches. The mechanical advantage of the wrench is its effective length (Le) divided by radius of the pitch circle.

Now calculate the pure mechanical advantage of the wrench (MAw) as Mw= Le/(Pd/2) = 44 inches/(0.6850/2) = 128:1. A single pound of input force on the torque wrench results in 128 pounds of output force.

To get the total pure mechanical advantage of this system, combine MAt and MAw. This is done by taking the product of the two values.

The total pure mechanical advantage (Mtot) of the two effects then becomes Mtot = Mt x Mw = 21.5 x 128 = 2,752:1. If the mechanical advantage actually attained this value, 15 pounds of input force would yield the bolt.

Obviously, it does not. The reason is, pure mechanical advantage of a system can never be attained. There are always (energy) losses.

In the instance of a bolt being torque tightened, those losses can be extraordinarily high. The most important energy loss is friction. To better understand how dramatically friction can negatively impact a bolt’s clamping force, evaluate its affect using a common, long-form version of the torque equation. Tlbf is the calculated torque to attain a bolt load, FB.

The first term in Equation 1 is the useful input energy that goes to stretching the bolt. The second and third terms account for the energy being lost to friction.


T = [(pt/2 π) + (utdt/2 cos(a)) + (un dn/2)] FB/12
Where:
pt = pitch of the bolt thread = 0.10 inch
dt = mean contact diameter of thread = 0.685 inch
dn = mean contact diameter on nut spot face = 0.8738 inch
a = half thread angle = 30 degrees
ut = friction coefficient on threads = 0.13
un = friction coefficient on bearing surface (spot face) = 0.08
FB = value of (single) bolt load = 17,561 lbf.
T = torque, in. lbf.
Equation 1


Specifically, the second term is the energy lost to friction between mating threads, while the third term accounts for the energy lost to bearing surfaces during the tightening process. Now evaluate these terms for the example bolt.

In addition to bolting geometry values, consider the published values of friction coefficients for a commonly used paste, lubricant. The definition and values for each variable are noted in Equation 1.

Substituting these into the respective terms they are evaluated and compared in Image 3. Term 1 is the useful work in creating the clamping force.

Image 3. Input energy going into stretching the bolt, and energy lost to friction

The sum of the other two terms is the energy loss to friction.

In this particular instance, with the presumed coefficients of friction, only ~16 percent of the applied energy is converted to the useful work of creating bolt stretch. A total of 84 percent of the tightening load is lost to friction. This explains why only a small portion of the system’s mechanical advantage is realized. The effect of friction should not be underestimated. A torque wrench measures the value of torque being input to the bolt system. It does not reveal how much useful energy is actually being delivered to the bolt.

Clearly, the proper use of lubrication can have a dramatic effect on the success of a bolted flange connection. The liberal use of lubrication is one of the easiest, least expensive, quickest and most effective ways to ensure the targeted clamping load is realized. In the case of gasketed, bolted flange joints, the extra energy transmitted produces a larger sealing stress on the gasket and ultimately results in few emissions and a cleaner, safer environment.


For more information about the right sealing solution for your specific application, contact Gallagher Fluid Seals.

This original article was features on Pumps & Systems website and was written by Randy Wacker, P.E., consultant for Inertech Inc.

Symptoms of Bad Valve Seals

Valve Seals Help Control Oil Consumption and Valve Lubrication

Valves are an important part of regulation in any system, and their seals are designed to be used in different types of engines for controlling oil consumption, and valve lubrication.The design and manufacturing of the seal is the key to ensure seal performance and longevity.

bad valve seals symptomsValves have many uses and are found in virtually every industrial process, including water & sewage processing, mining, power generation, processing of oil, gas & petroleum, food manufacturing, chemical & plastic manufacturing and many other fields.

Some examples of valve seals include: ball valve seats, globe valve discs, stem packing, stem seals, valve discs, valve packing, valve seals, and valve stem packing.

Having a proper valve seal can save you thousands of dollars in repairs at the end of the day, so it’s important to check them semi-regularly. For example purposes, we’ll focus on cars, but this can be translated across a variety of systems and industries. Here are some symptoms of a bad valve seal that may need to be replaced:

Performing the Cold Engine Test

One sure-fire way to tell if you have a faulty valve seal is to perform a cold engine test. When your vehicle has been sitting overnight or for a longer period of time, the top of the head of the valve cover will have some oil left over from the last time you drove. When you start the engine, the oil ends up getting sucked down through the bad seal into the combustion area, producing a blueish smoke out of the tailpipe. This may indicate that your valve is not securely sealed and that it’s time to get a new one.

Idling

Another way to test a bad valve seal is to be aware of what happens while your vehicle is idling. When your vehicle is stopped for a significant amount of time, high vacuum levels will cause the oil to build up around the valve system while it is closed. In a faulty valve seal situation, when you begin to accelerate again, this oil can end up getting sucked past the seal an into the valve guide. This causes more of this blueish smoke, due to the burning of oil, to come out the tailpipe.

High Levels of Oil Consumption

High levels of oil consumption is another indicator that you have a bad valve seal. This is because oil is being leaked out or burned excessively and causing oil to decrease at a higher rate than normal. You can detect this loss of oil with a basic oil dipstick and keeping a regular log of oil levels. If no oil leaks can be found around the vehicle, you may still have a bad valve seal, as the oil will likely be burned up causing excessive smoke.

High Levels of Smoke

Another indicator of a faulty valve seal, as mentioned above, is the high presence of smoke. It’s common for some exhaust smoke to be present when you first start your vehicle, but if it begins to last longer than normal, your valve seal may be deteriorating. In addition, if you have a bad valve seal, the excessive smoke will tend to come in waves as an indicator of oil burning.

Engine Braking Test

Engine braking is when other ways besides external braking are used to slow down your vehicle within an engine. When you have a bad valve seal, the oil that collects at the front cover of the head will end up burning when you push on the accelerator after coasting for a while. This is apparent especially when going downhill and again will be indicated by the excessive smoke that leaves the tailpipe. The oil here burns longer than in normal cases.

Acceleration Power is Compromised

The final indicator of a poor valve seal is a lack of acceleration power. You can also perform a compression test to see if this is the case. A higher level of compression will indicate that it’s a valve seal problem, while a low level of compression will indicate a piston ring problem. These two areas can be very similar in their faulty symptoms so it’s best to be informed on their differences.

A badly designed seal can result in engine oil flooding, which can eventually cause a breakdown. Gallagher Fluid Seals understands the importance of a well-designed industrial seal and can help design a custom solution for you, or supply you with standard off-the-shelf seals from the world’s top suppliers.


For more information about valve seals what why they fail, or to find solutions, contact Gallagher’s engineering department.

The original article can be found on Real Seals’ website.

The Complete Guide for Mechanical Seals & API 682 4th Edition Piping Plans

Mechanical Seals & API 682 4th Edition

A sealing system, consisting of a mechanical seal and an associated supply system that is balanced by individual applications, is the utmost guarantee for a reliable sealing point and uninterrupted pump service. The performance of the seal is greatly influenced by the environment around the seal faces, making the provision of suitable, clean fluids as well as a moderate temperature an essential topic.

This guiding booklet provides a condensed overview of all piping plans established by the API 682 4th edition guidelines. Each illustrated piping plan is briefly described, and a recommendation that considers the media characteristics in terms of the relevant application and corresponding configurations is given to help you reliably select your sealing system. Furthermore, the content of this booklet has been enriched by providing clues – so-called ‘remarks and checkpoints’ – where EagleBurgmann shares the experiences gained from multiple equipped plants.

Sealing solutions to meet any requirement

Several factors play a major role when choosing the product, the product type, the materials used and how it is operated: process conditions at the sealing location, operating conditions and the medium to be sealed.

No matter what requirements our customers have, EagleBurgmann understands how these factors affect functionality and economic viability, and they translate this expertise into outstanding long-term, reliable sealing solutions. EagleBurgmann has all the expertise needed to manage and support the entire development, life and service cycle of its sealing solutions.

Plan 75 Piping Plan Example

EagleBurgmann and API 682

EagleBurgmann offers customers the widest product portfolio of seals and seal supply systems according to API 682 4th edition. The configurations listed for each individual piping plan are to be understood as recommendations including possible utilizations which may also be applied.

EagleBurgmann Profile

EagleBurgmann is one of the internationally leading companies for industrial sealing technology. Their products are used wherever safety and reliability are important: in the oil and gas industry, refining technology, the petrochemical, chemical and pharmaceutical industries, food processing, power, water, mining, pulp & paper and many others. More than 6,000 employees contribute their ideas, solutions and commitment towards ensuring that customers all over the world can rely on their seals and services. More than 21,000 EagleBurgmann API-seals and systems are installed world-wide.

What to Know, Avoid, and Consider When Planning Seals for Medical Devices

Seals are one of the most important components in many medical devices. While small in cost, seals for medical devices have a profound affect on the function of said device and the outcome of a medical procedure.

Engineered sealing solutions have advanced to meet the new medical device designs due both to new materials and to new processes for producing these seals. An understanding of the fundamentals of seal design, the tools available to assist in the manufacturing process and pitfalls to avoid will help in achieving a successful seal and medical device outcome.

Classifying the three basic seal designs

When approaching a new seal design, It is important to classify the seal based on its intended function. All seals fall into one of three distinct groups. While certain applications may combine more than one group, there is always one that is dominant. The three basic seal designs are:

Static — seal applications where there is no movement.
Reciprocating — seal applications where there is linear motion.
Rotary — seal applications where there is rotation.
Static seal applications are the most common and include those that prevent fluids and drugs from escaping into or out of a medical device. The seal design can range from basic O-rings to complex shapes. Static seals can be found in the broadest range of medical devices from pumps and blood separators to oxygen concentrators.

trocar design
New advances in trocar designs incorporating specialized seals allow multiple instruments to be inserted in the single trocar.

A reciprocating seal application with linear motion would include endoscopes that require trocar seals. These trocar seals are complex in design and allow the surgeon to insert and manipulate instruments to accomplish the medical procedure. These procedures range from relatively simple hernia repairs to the most difficult cardiac procedures. All of these minimally invasive surgeries employ endoscopes with seals that rely on seal stretch, durability and ability to retain shape during lengthy and arduous procedures. This particular seal application combines both reciprocating and rotary motion with the main function being linear motion.

A rotary seal application most commonly includes O-rings used to seal rotating shafts with the turning shaft passing through the inside dimension of the O-ring. Systems utilizing motors such as various types of scanning systems require rotary seals but there are many other non-motorized applications that also require rotary seals. The most important consideration in designing a rotary seal is the frictional heat buildup, with stretch, squeeze and application temperature limits also important.

Function of a particular seal design

What is the function of the seal? It is important to identify specifically if the design must seal a fluid and be impermeable to a particular fluid. Or will the seal transmit a fluid or gas, transmit energy, absorb energy and/or provide structural support of other components in device assembly. All of these factors and combinations need to be thoroughly examined and understood to arrive at successful seal design.

A seal’s operating environment

In what environment will a seal operate? Water, chemicals and solvents can cause shrinkage and deformation of a seal. It is important therefore to identify the short and long term effects of all environmental factors including oxygen, ozone, sunlight and alternating effects of wet/dry situations. Equally important are the effects of constant pressure or changing pressure cycle and dynamic stress causing potential seal deformation.

There are temperature limits in which a seal will function properly. Depending on the seal material and design, a rotary shaft seal generally would be limited to an operating temperature range between -30° F and +225°F. To further generalize, the ideal operating temperature for most seals is at room temperature.

Expected seal life – How long must the seal perform correctly?

Continue reading What to Know, Avoid, and Consider When Planning Seals for Medical Devices

Enhanced Surface Profiles for Gaskets

How this feature can improve performance and efficiency with gaskets

Gaskets have always been part of industrial production. However, gaskets have not always been forgiving, easy to use or simple to remove. What if the sealing products were designed to optimize the work put into them? What if the design had a level of intelligence built in? What if the design could make up for equipment damage? When used properly, enhanced surface profiles for gaskets can reduce leaks, spills and other releases that can damage the environment, put people at risk, result in fines and lead to costly downtime.

Using surface profiling to reduce area and increase stress is found in everyday life, from the soles of running shoes to the treads on vehicle tires. Reducing the contact area while maintaining compressive force results in increased stress. In the case of gaskets, traction or friction between a gasket and the flange faces is critical to holding internal pressure. If the downward force created by the fasteners in a flange is diluted or spread over a larger area, the overall stress is reduced.

Compressibility

Adding raised features to the surface of a gasket to reduce contact area and increase stress also tends to impact compressibility. Compressibility represents the ability of the gasket to conform to the surfaces it is being used to seal. Flange surfaces usually show signs of wear, pitting, scratches or other defects. It is cost-prohibitive to make two mating flange faces smooth and flat enough to seal without a gasket. The more compressible a gasket is, the better chance the user has of attaining an effective seal.

picture showing different gasket views
Image 1. (clockwise left to right) Traditional material sees heavier load around the gasket bolts and lighter load farther from the bolts. Image 2. Load distributed more evenly. Image 3. More stress toward the bolts. Image 4. Stress spread evenly around the gasket. (Images courtesy of Garlock)

Pressure Resistance

Compressibility also impacts the amount of pressure exposure on the gasket. When a flange assembly is pressurized, the internal media pushes outward on the inner diameter of the gasket. The thinner a gasket becomes, the less outward force it sees from internal pressure. This is referred to as improved “blowout resistance.” Unfortunately, one common error made when a gasket blows out is to replace it with a thicker gasket. This puts more gasket surface in the pipe or vessel for the internal pressure to act on.

Sealability

To create an effective seal, there are two functions the gasket must accomplish.

First, it needs to conform to the flange face to prevent the media from passing between itself and the flange faces. This is where the compressibility is important. Continue reading Enhanced Surface Profiles for Gaskets

Measuring Metal Hose Assembly Lengths

“Which way do I measure this metal hose?”

A common question among some customers who use metal hoses is: “Which way do I measure this metal hose?” Well, there’s a few different options.

  1. The first method is to measure the overall length of the assembly.
  2. Or, the live flexible length of the hose assembly can be measured.

Live Length vs Overall Length

Traditionally, the live length – or the amount picture showing live length versus overall lengthof flexible hose between the fitting – is used to determine whether there is sufficient hose length to accommodate a certain offset or movement, whereas the overall length of the assembly would be used to determine if the hose is going to fit in an application.

When measuring the overall length of the hose assembly, make sure to measure the overall length via end-of-fitting to end-of-fitting and if it has floating flanges on it, remember to measure to the face of the stub end on that floating flange.

JIC Swivel Fitting

If it’s a female JIC swivel fitting, however, it’s not necessary to measure the overall length to the end of the nut. Measure to the seat of the JIC inside the female swivel fitting. This is the standard for the metal hose industry.

Some customers may measure the overall diagram showing measurements with centerlinelength to the end of the JIC nut because some standards are measured differently by hydraulic manufacturers. If there are elbow fittings on the ends of the hose, metal hose industry standards dictate that measurements should be taken to the centerline of those elbow fittings rather than measuring the outside of the radius of the bend on those elbow fittings.

Laid flat with no kinks or bends

When measuring the length of a hose assembly, make sure it’s laid flat without any kinks or bends in the assembly. If it’s a strip wound hose assembly, ensure that strip wound hose is in its relaxed length, midway point between fully compressed and fully extended. Then, take the measurements on the length of that assembly.

For a great visual representation of measuring metal hose assembly lengths, watch this informative video below from Hose Master:


This video was produced by Hose Master and can be found on their Youtube channel or on their website.

For more information, contact Gallagher Fluid Seals or call 1-800-822-4063.

The Advantages of Crimped Can Seals

A combination of crimped can seals will handle a variety of applications when a rubber lip seal is not your solution.

Rotary seals are often secured in sealing hardware by crimping the sealing element in a metal can. One of the most common rotary seals is a molded rubber lip seal in a can. 

While not crimped, the can retains the sealing element, and stops the seal from rotating in the gland. Rotary sealing elements for low pressure (under 15 psi), are often nitrile or Viton rubber sealing elements.

This style of seal comes in many cross sections, and may include garter springs to help the seal stay engaged with the shaft. These seals are typically low in cost, and produced in high volume.

These seals are found in many low-pressure applications. However, as the pressures begin to climb over 10 psi and speeds run over 500 ft/min, friction generates heat, which accelerates wear on the rubber element and in turn begins to wear the mating shaft material.crimped can seal

Overcoming Friction

Friction or the resultant heat is the largest concern in rotary service.

The crimped can seal with PTFE (Teflon) elements can run with pressures in excess of 500 Psi and PV (pressure- velocity) reaching over 350,000psi-ft/ min. The crimped can allows these elements to remain secure.

The crimped case seal causes all the relative motion to remain at the sealing lip interface. With the crimped can, we have the opportunity to install multiple lips or seal cross sections to handle a variety of loads. This allows us to control leakage, and keep friction to a minimum.

We can seal most any fluid or run dry sealing gases with little or no lubrication. With widely varying temperatures, we can include springs to maintain seal contact, offset some eccentricity of shafts, keep dirt out or keep very light loads.

Continue reading The Advantages of Crimped Can Seals

Water Regulations and NSF 61 Compliant Elastomers

Replacing Aging Water Infrastructure With NSF Compliant Materials

There are over 155,000 public water systems in the United States and more than 286 million Americans who rely on community water systems daily.  Since most of the infrastructure was built between the early 1900’s and 1960 using outdated technology/products and capabilities, nearly everything is approaching the natural end of it’s lifespan.

Some estimates put the repairs and replacement of thePicture of NSF Compliant Gaskets infrastructure between $250B and $500B over the next 20-30 years. Several applications will need to be updated or fully replaced for the safety of consumers and quality of delivery, including:

  • Joining and sealing materials
  • Mechanical devices
  • Pipes or related products
  • Process media
  • Plumbing devices
  • Non-metallic potable water materials
  • Hydrants
  • and Public drinking water distribution (tanks and reservoirs, maters, individual components)

Joining and Sealing Materials

When these systems were being constructed and assembled decades ago, there were limited regulations and requirements that needed to be met. Gaskets, at least the traditional ones, were often made in two different ways: (1) Red Rubber (ASTM D1330 Grade 1 &2) with compressed non-asbestos or (2) cloth-inserted rubber with compressed asbestos.

However, today’s acceptable gasket requirements for the potable water industry differ greatly from those in the past. Gaskets have strict guidelines to abide by and must be:

  • Chemically resistant
  • NSF compliant
  • Food grade compliant
  • Electrically isolating

Because of the need for health and safety, the National Sanitation Foundation (NSF) was created in order to establish minimum requirements for the control of potential adverse human health effects from products that contact drinking water. In addition to gaskets, the NSF covers a variety of products and parts relevant to the water industry, including: pipes, hoses, fittings, cements, coatings, gaskets, adhesives, lubricants, media, water meters, valves, filters, faucets, fountains, and more.

So you might ask – why does the NSF require different materials and regulations for gaskets compared to years ago?

First things first – leaks are a major issue with the aging infrastructure. Improperly placed gaskets & seals or faulty products can cause leaks. This in turn could pose health risks to people drinking potable water or using products processed with potable water.

Additionally, the treatment process and chemicals utilized are Picture of NSF 61 Compliant Sealsdifferent from previous “standard” products. For example, research and testing over many years has concluded that traditional gaskets, which were used many years ago, could pose a safety threat to those drinking water processed with specific materials. This led to updated regulations for NSF 61’s drinking water system components.

Lastly, engineered sealing solutions are more important than ever. There’s a wide variety of custom engineered water systems throughout the U.S. – climate, geographic terrain, and the needs of the community are all reasons for why water infrastructure is so unique. Because of this, custom gaskets, seals, and other products are needed to supplement those systems.

Luckily there are many companies dedicated to providing the highest quality NSF 61 products. These trusted brands have proven materials to count-on when replacing or repairing water infrastructure:

Garlock’s NSF 61 Family of products

Parker’s NSF compliant products

Freudenberg’s new generation of NSF products

For more information on how Gallagher Fluid Seals’s engineers can help you with a custom solution, call us at 800.822.4063

A User’s Guide to Expansion Joint Control Units

Expansion Joint Control Units

Elongation settings are a vital factor to assembly effectiveness.

Diagram of Control Unit and Control Rod Components

It is no secret that one of the greatest demands for an expansion joint is the expectation to serve a long, leak-free life with little-to-no maintenance. Once installed, these flexible rubber connectors should require little attention. The preservation of this investment (and one’s sanity) can be maximized with an in-depth overview of how control units can prevent a new expansion joint from being overstressed.

The purpose of a control unit is to act as a safety device against excessive movement resulting from pressure thrust. A typical control unit assembly is comprised of threaded rods, steel gusset plates, nuts and washers (see Images 1 and 2).Diagram of Effects of Pressure Thrust

The usage of control units with an expansion joint is always beneficial; pressure spikes during a system upset can cause uncontrolled surges through the expansion joint. This is a prime example of how valuable it is to have control units installed to protect these rubber assets from damage.

Methods to the Madness

A common misconception about control units  is that they are designed to support the weight of pipe members or act as a substitute for adequate mounting. They are not. The sole purpose of a control unit is to allow the expansion joint to move freely within a specific range of movement while preventing the joint from being overstretched from pressure thrust forces.

The control units in no way impede the joint from performing its other duties beyond movement  (vibration absorption, cycling or compensation for misalignment). The few extra steps needed to install the control units with the expansion joint could pay notable dividends in the long run.

Pressure thrust plays a huge role in how an expansion joint functions. While under pressure, the forces acting on the inside walls of the expansion joint actually cause the joint to swell and elongate. In the real world, an expansion joint is held comfortably between two pipe flanges, which in most cases are restrained by a pump lagged to the floor or mounted to a structural beam. Although it may not be apparent to the naked eye, once the expansion joint sees pressure, it produces a thrust force that acts axially on both pipe flanges.

Theoretically, what would be the result if the expansion joint was unrestrained on each end while pressurized?

Without fixed ends, the pressure thrust would force the joint to elongate without bounds.

Most useful in high pressure applications, the control rods will  engage with the gusset plates once a pre-specified amount of growth for the expansion joint has been reached, restricting the joint from stretching any further. At this point, the control rods are absorbing any additional thrust  acting on the pipe flange, thus limiting the amount of stress that is exerted onto adjoining equipment.

The design theory for sizing control unit hardware is based on the pressure thrust. Nominal inside diameter (ID) and arch geometry of the expansion joint are key drivers for calculating the thrust force that will be applied to the pipe at maximum line pressure. Per

Arch Diameter Diagram

industry standards set by the Fluid Sealing Association (FSA), both control rods and gusset plates are designed to withstand no more than 65 percent of the yield strength of the material.

Magnitude of the pressure thrust can be calculated by knowing the internal pressure and the effective area of the expansion joint. Effective area is found using the arch diameter of the expansion joint, which takes into account the size of the arch.

For example, we can calculate the resulting pressure thrust for a 10-inch ID expansion joint using an arch height of 1.5 inches that is rated for a maximum pressure of 250 pounds per square inch (psi).

The equation for pressure thrust “T” is:

Equation for pressure thrust

These design limitations based around yield stress are the reasons why some control units made from lower yield strength stainless steel contain thicker components or more rods per set than the standard carbon steel control units.

Installation & Inspection

For a control unit assembly to be effective, rod positioning and elongation settings are critical during installation. Each control rod should be evenly spaced around the flange to best distribute the load. Elongation settings (see Image 5) are often overlooked, yet are a vital factor to ensure the control units fulfill their intended use.

Every expansion joint comes with movement ratings based on arch size, configuration and number. These movement design ratings of the expansion joint are critical pieces of information that are absolutely required during the installation of control units. The general rule of thumb is the gap between the gusset plate and the nut should be adjusted to match the joint’s elongation rating.

Having this information at hand during installation is great, but what about the existing control units currently in operation? Visual inspections of these components are a basic task that goes a long way toward extending the life of the joint.

Here are the top 4 anomalies to look for when performing a field inspection: Continue reading A User’s Guide to Expansion Joint Control Units