Category Archives: Uncategorized

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  Since most of the infrastructure was built between the early 1900’s and 1960 using outdated technology/products and capabilities, nearly everything is approaching the natural end of it’s lifespan.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

Do’s and Don’t of Installing Metal Hoses (Part 1)

Metal Hose Applications

Metal hose applications can be tricky. Hoses can fail or have a variety of other problems due to a few different factors: improper installations or outside factors from the surrounding piping system. In this video, Erik Kane, Hose Master’s Product Specialist, discusses various do’s and don’ts when installing metal hose. Follow these tips and more to help maximize the life of your hose and optimize your safety.

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

85 Years of the Simmerring®

Small, nondescript and ostensibly unspectacular – it is often developments of this exact description that lead to groundbreaking innovations in the world of technology. The idea of manufacturing seal sleeves from leather scraps became the starting point in one of the most important developments in sealing technology: the Simmerring®. For 85 years, the Simmerring has been inseparable from the Freudenberg history of success, and, in Europe, its name has even become a synonym for (radial) shaft seal rings of every kind. Today the Simmerring is a high-tech product whose key functions go far beyond the sealing of the shaft against its housing.

Freudenberg SimmerringIt all started with the economic crisis of 1929, which plunged the leather industry and thus the Freudenberg tannery – which was founded in 1849 – into difficulties. To better distribute its risks in the future, Freudenberg began to diversify the company and serve a broader market. A sample of a leather sleeve from the United States was the inspiration for giving Walther Simmer and his team the job of developing a machine that could be used to produce lip seals made of leather scraps.

Continue reading 85 Years of the Simmerring®

New Sealing Material HiFluor® FB

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Blog.


New Sealing Material HiFluor® FB for Hygienically Sensitive Applications

HiFluor® FB - Hygienically Sensitive Sealing MaterialBe it in the production of food, pharmaceuticals and cosmetics or medical devices coming into contact with the human body, excellent purity and media resistance combined with a wide range of robust properties is always required of the materials used for the components in the manufacturing processes. Specifically for these challenging applications, Parker has developed a new sealing compound with very good mechanical properties and excellent permanent elasticity: HiFluor® FB V8991.

Fluoroelastomeric materials have proven their viability in chemical and food processing, cosmetics, pharmaceutical and life science applications involving non-polar solvents, aliphatic compounds, greases, oils and aromatic substances whenever the resistance of standard materials such as hydrogenated nitrile butadiene rubber (HNBR) and ethylene propylene rubber (EPDM) is no longer sufficient.

Innovative “Pure” Sealing Solution HiFluor® FB V8991

As a compound and seal manufacturer, Parker Prädifa, in the light of the growing demands made on sealing elements in the aforementioned markets, has developed a HiFluor® FB compound with very good mechanical properties and excellent permanent elasticity.

Continue reading New Sealing Material HiFluor® FB

What is a Spring Energized PTFE Seal?

spring

Spring energized PTFE seals perform reliably in a variety of applications where conventional elastomeric seals fail due to chemical attack, extreme heat or cold, friction, extrusion or compression set.

PTFE seals have three basic design elements:

  • A pressure-actuated U-shaped jacket
  • A metal spring loading device
  • High performance polymeric seal materials

So what is a spring energized PTFE seal? It’s a spring-energized U-cup that uses a variety of jacket profiles, spring types and materials in rod and piston, face and rotary seal configurations. They are used when elastomeric seals fail to meet temperature range, chemical resistance or friction requirements.

Jacket profiles are made from PTFE and other high performance polymers. Spring types are available in corrosion-resistant alloys, including stainless steel, Elgiloy and Hastelloy.

Continue reading What is a Spring Energized PTFE Seal?

How Maintenance Can Stop Hydraulic System Failure

Hydraulic piston system for bulldozers, tractors, excavators, chrome plated cylinder shaft of yellow machine, construction heavy industry detail, selective focusAs you set out to reduce hydraulic system failure, it’s important to recognize sources of contamination as part of your maintenance program.

Our partners at Parker, long-time suppliers of O-rings to Gallagher Fluid Seals, offer these common forms of contamination in your hydraulic systems:

Continue reading How Maintenance Can Stop Hydraulic System Failure

PTFE Rotary Seal Shaft Considerations

shaft table 3As we continue this blog’s PTFE series, we’re going to take a closer look at PTFE rotary seal shaft considerations.

In rotating applications, proper surface finish is crucial for getting positive sealing and the longest seal life possible. Rotating surfaces that are too rough could create leak paths and can also be very abrasive. Unlike elastomer contact seals, PTFE lips can run on very smooth surfaces regardless of lubrication.

Continue reading PTFE Rotary Seal Shaft Considerations

HNBR Sealing Compounds for Energy, Oil, & Gas Service

HNBR compoundsParker’s HNBR sealing compounds provide cost-effective solutions in aggressive EOG environments.

N1173-70, N1231-80 and KB163-90 are sealing compounds made from hydrogenated nitrile, a synthetic polymer that results from the hydrogenation of nitrile rubber (NBR). The hydrogenation process gives HNBR materials enhanced thermal stability (up to 149°C/300°F, with short periods at higher temperatures).

HNBR materials also possess superior mechanical properties and enhanced fluid compatibility over standard nitrile compounds. These properties allow HNBR materials to be a  cost-effective bridging compound between nitrile and fluorocarbon elastomers.

Continue reading HNBR Sealing Compounds for Energy, Oil, & Gas Service

Extruded and Spliced Seals from Parker

extrudedParker’s precision extruded and spliced seals offer an ideal, cost effective sealing solution for many applications.

Their spliced products include hollow low-closure force seals, large diameter rings that cannot be molded, “picture-frame” gaskets and custom configurations for non-standard grooves. Rings are available in a wide range of sizes with capabilities for very tight tolerances.

Customers can choose from a large variety of profile cross-sections and different material technologies. Parker’s superior vulcanization technology offers high bond strength, uncompromised chemical resistance and consistent flexibility.

Continue reading Extruded and Spliced Seals from Parker