Pros & Cons of ePTFE Gasket Material

Mar 22, 2023

By: Mortaza Pasandideh Quality/Application Specialist, Triangle Fluid Controls Ltd.

Expanded Polytetrafluoroethylene (ePTFE) is a high-performance sheet gasket material made of multi-directionally expanded 100% Virgin PTFE and used in various industries such as chemical, pharmaceutical, and food processing. It is known for its exceptional resistance to chemicals and high temperatures, making it an ideal choice for sealing applications in harsh environments.

ePTFE gaskets are a popular choice in many industries due to its unique properties, but when it comes to selecting the right gasket material for your application, it is crucial to consider the pros and cons of each option.


  • Chemical resistance: ePTFE gaskets can withstand a wide range of aggressive chemicals, including acids, bases, and solvents. This makes them ideal for applications in the chemical, pharmaceutical, and food processing industries.
  • High-temperature resistance: Due to the multidirectional structure, ePTFE gaskets can maintain their mechanical and sealing properties at high pressures and temperatures.
  • FDA Compliant: ePTFE is non-toxic, making it safe for use in most of the food and pharmaceutical applications.
  • High compressibility: ePTFE gaskets can conform to irregular surfaces and maintain their seal even under extreme pressure.
  • Resistance to creep and cold flow: making it an ideal choice for demanding applications that require a long-lasting, reliable seal.


  • Not suitable for use in abrasive environments: ePTFE gaskets are relatively soft and can be easily damaged by abrasive substances, so they may not be the best choice for abrasive media.
  • Requires careful installation or removal: ePTFE gaskets can be easily damaged during installation or removal, which can compromise their sealing ability.
  • Expensive: ePTFE gaskets can be more expensive than other gasket materials due to the required complex manufacturing process.

Durlon® Joint Sealant (ePTFE tape) is made from ePTFE sheets and is often used as a cost-effective alternative to ePTFE cut gaskets on flanges with large diameters. This type of sealing can accommodate any flange shape and size, eliminating unnecessary stock inventory.


Durlon® Joint Sealant comes with a self-adhesive backing making the installation process easy for maintenance and overhaul purposes when applying or removing.

Overall, ePTFE gaskets offer a wide range of Pros such as its high chemical resistance, that make them an excellent choice for a variety of applications. However, with Factors such as its high cost, it is important to weigh both the Pros and Cons of ePTFE gasket material before choosing it for a specific application.

Contact our Technical Team for more information about Expanded PTFE (ePTFE) Gaskets.

Reduced Contact Area (RCA) Gaskets

Oct 26, 2022

By: Mortaza Pasandideh Quality/Application Specialist, Triangle Fluid Controls Ltd.

Gaskets are used in flange joints to prevent leakage. It is necessary for all gasket materials to have enough flange pressure to compress the gasket to form a tight, unbroken seal. The number, size, and grade of bolts used in the application determine the bolt load available. However, the leakage in bolted flange connections is significantly influenced by the sealing surface’s contact area. Low-stress sealing systems typically have little tolerance for high bolt torque to avoid damage to the flange.

“Reduced Contact Area ” or RCA® Gasket design is an effective solution to get the best low-torque seal in load-compromised applications. The contact area of the flanges in a sealing system is fixed, regardless of the type and form of the gasket. Any acceptable gasket material has a predetermined minimum stress requirement which is a function of operating pressure. Additionally, the maximum permitted bolt torque dictated by gasket material, bolt material, or flange material is also fixed and cannot be changed. The gasket geometry design and the consequent surface area is the only variable left. The sealing concept behind the RCA configuration is to reduce the total sealing contact area resulting in a higher gasket stress at a given bolt load while preventing flange rotation. RCA gaskets are ideal for brittle, non-metallic flanges where the excessive assembly bolt load required to compress the standard full-face gasket is not available. RCA gaskets are suitable for FRP, PVC, PVDF, Cast Iron & API manways. They provide leak-free performance without the hassle of cracked flanges.

Durlon® Reduced Contact Area Gaskets (RCA) are available in standard 1” to 24”, Class 150#, Full Face sizes. They can be cut from Durlon® PTFE, Compressed Non-Asbestos material, HT1000®, and Flexible Graphite sheets. RCA gaskets fabricated from selected Durlon PTFE are oxygen service qualified and conform to FDA requirements. Additionally, installation of RCA gaskets is easy because they have identification tabs and alignment guides. Since RCA gaskets can be cut from standard sheets, compared to other low-stress gaskets, they are cost-saving sealing solutions for the end users.

The below graph illustrates a 3” 150# Full Face gasket using FEA analysis to show the applicable stresses that are being applied to the gasket while bolted up in the flange. The gradual shades of grey (from light to dark) show stress intensity. Blue indicates very little, or no stress is being applied at all to those areas of the gasket.

Features and Benefits
  • Low Seating Stress
  • Leak-free performance in low bolt-stress applications
  • Protecting the flange from cracking
  • Easy identification and installation
  • Conformability to a wide variety of sealing surfaces and irregular surfaces
  • FDA and Oxygen service qualified options as well as high-temperature styles available

Contact our Technical Team for more information about Low Seating Stress Gaskets.

Mill Test Reports in the Gasket World

Mar 29, 2022

By: Alireza Zandi Karimi, Applications Engineer, Triangle Fluid Controls Ltd.

In general, Mill Test reports frame the key steps in a metal product’s journey: the step from the steel mill that melted the metal; to the distributor, the mill sold the metal to. Mill Test Report (MTR) – also referred to as a Mill Certificate, Material Test Report, Metallurgical Test Report, Certificate of Inspection or Certificate of Test – is a quality assurance document used in the metals industry that certifies a material’s chemical and physical properties. An MTR shows a metal product’s (steel, aluminum, brass, or other alloys) compliance with international standards. e.g., ANSI, ASME, etc. Below, we will have a closer look at MTRs in the gasket industry.

What’s Included in an MTR

In the gasket world, there are products that are either made entirely from metals (Ring Type Joint gaskets) or consist of several metallic components (Spiral Wound Gaskets, Kammprofiles Gaskets, etc.). Either way, an MTR can be produced. A gasket MTR may include some, or all the following information:

Product Description

Gives the customer an overview on a product’s type, style, configuration, etc. Here is a product description example in a spiral wound gasket MTR:

SS316 Spiral Graphite Filled Gasket with Carbon Steel Outer Ring SS316L Inner Ring as per ASME B16.20

Additional information on product’s grade, temper, thickness, dimensions, surface finish, etc. may also be included.

Material Heat Number

Signifies the batch in which a piece of metal originated. It provides traceability and verifies quality. The heat number is marked on all Durlon’s metallic and semi-metallic gaskets before they leave the manufacturing facility. For products consisting of multiple metal components such as spiral wound gaskets, the heat number for each component is specified.

Physical/Mechanical Properties

Lays out the strength, hardness, ductility, and elasticity of a metal product. In the context of gaskets, the physical and mechanical properties of each metallic and non-metallic (filler) component is specified separately in the gasket MTR.

Chemical Analysis

Provides a chemical breakdown on the material. The chemical makeup of the metal may vary depending on what alloy the gasket is made of, therefore a chemical analysis for each metallic and non-metallic (filler) component is included in the gasket MTR.

Type of Specifications Met

Lists all the certifications and specific standards that the product complies with.

Country of Origin

Specifies the country where the raw material was melted and manufactured.

Additional Details

Any additional specifications or extra information relevant to a customer’s order will be on the MTR.

How To Approach MTRs The Right Way

Handling MTRs properly is an important part of quality management systems. The chart below is a simple depiction of the complex and overlapping distribution system within the metals industry. Creation, distribution, receipt, and storage of MTRs is a time consuming and expensive process. Retaining hard copies of Quality Assurance documents for all products can result in a multitude of copies of the same document in a variety of different filing cabinets and document management systems. At Triangle Fluid Controls Ltd.® we use MetalTrace®, a software specifically created to handle MTRs and is widely used in the metals industry. It enables us to quickly and easily create and manage MTRs for gaskets, making digital copies easily available to our distribution channel via the MetalTrace® portal.

Why MTRs are Important?

MTRs provide traceability and assurance to the end user by stating the quality of the material, and the process used in its production. They create a system of checks and balances, which is critical for products such as metallic or semi-metallic gaskets to meet international standards and comply with industry regulations. Part-marking traceability provides a documented trail of each product, its history, components, quality, and safety which ensures transparency and accountability through the supply chain.

Contact our Technical Team for more information about MTRs.

Impact of Flange Finish on Gasket Performance

Mar 28, 2022

By: Sylvia Flegg, Marketing Manager, Triangle Fluid Controls Ltd.

Considered an essential component, a flange is a type of mechanical seal that can connect valves, steam traps, strainers, and alike, in a piping system. While non-metallic flanges such as glass and reinforced plastic are used for some services, most flanges are metal.

Ultimately, and in their simplest form, two flanges are joined together and have a gasket placed between them. The importance in choosing the right gasket is vital to an application’s reliability and integrity.

A critical and fundamental aspect of sealing is the level of friction between the flange and gasket surfaces. The roughness of the flange faces can have a dramatic effect on gasket creep relaxation, blow-out resistance, and bolted joint tightness. Depending on the type of gasket used in the connection, different flange surface finishes should be utilized to optimize gasket performance.

The 4 basic finishes for ASME B16.5 and B16.47 flanges are the Stock Finish, Spiral Serrated Finish, Concentric Serrated Finish, and Smooth Finish.

Stock Finish

This is the Standard Flange Finish and is most widely used unless otherwise specified by the purchaser. The Stock Flange Finish is a continuous groove produced by using a 1/16” radius round-nosed tool with a feed of 1/32” per revolution.

Spiral Serrated Finish

The Spiral Serrated Finish is also a continuous groove like the standard stock finish in that the groove is generated with a 90° included angle “V” tool. The Groove is 1/64″ deep and the feed is 1/32″ for all sizes.

Concentric Serrated Finish

As the name suggests this surface finish is made up of concentric grooves. A 90° included angle “V” tool is used and the grooves are 1/64″ deep and 1/32″ apart.

Soft gaskets, such as compressed non-asbestos, PTFE and flexible graphite composite gaskets are most used to seal flanges with a serrated finish.

Smooth Finish

The Smooth Finish can be produced using several different shaped tools. This finish shows no visible serrations and has a 63-125 Ra. This finish in the past was commonly known as “Smooth Plane.” This term, however, should be avoided as it can be confused with “flat-faced” which applies to the flange facing and not to the gasket surface finish. Smooth finish flanges are more common for low pressure or large diameter pipelines using Spiral Wound Gaskets.

Guidelines for a safe seal:

  • A minimum seating pressure must be achieved to make the gasket material flow into the flange surface irregularities. The total force required to make this occur is proportional to the contact area of the gasket and the flange. Bolting force may be lowered by reducing the gasket area or the flange contact area.
  • The closer together are the ridge surfaces of a concentric serrated finish and the shallower are the grooves (the Ra), the more the flange area begins to resemble a smooth face flange, and hence there is more contact area. Higher bolt loading is therefore required to seat the gasket. The opposite effect occurs as the ridge spans become wider.
  • In the limit, with a very smooth flange, there will be reduced friction restraining the gasket from extruding outwards under the influence of the internal pressure of the retained medium.
  • A spiral serrated (phonographic) finish is more difficult to seal than a concentric serrated finish. The complete flow of gasket material must reach the bottom of the ‘valley” surface in a phonographic finish to avoid a spiral leak path from one end of the spiral to the outside.
  • Serrated and phonographic finishes are often associated with pipe flange assemblies, whereas commercial ground finishes are likely to be found in flanged joints other than pipe flange assemblies.


The finish or the condition of the gasket seating surface has a definite effect on the ability of the gasket to create a seal. Sheet gasketing is designed to have a seating stress that allows the gasket material to “flow” into the serrations and irregularities of the flange face. This “bite” aids the gasket in resisting the effects of internal pressure, creep, and cold flow.

Flange surface finish is critical to achieve the design-sealing potential of the gasket. Metallic, semi-metallic, and nonmetallic gasket materials interact with flange surfaces differently. Each of these gasket types require specific ranges of surface finish for optimum gasket performance with lowest leakage. Metallic gaskets require a smoother flange finish than either semi-metallic or nonmetallic.

Again, gasket-leak tightness is dependent upon its operating gasket stress. Flanges that are warped, pitted, rotated, and have incorrect flange gasket-surface finish will impair the leak tightness of the gasket.

Follow ASME PCC-1 guidelines on contact surface finish, surface flatness, and defect depth to exploit the best gasket performance and avoid leaks.

It is always best to consult with the gasket manufacturer to determine the best combination of flange surface finish, gasket design, and gasket material(s).

Watch our YouTube video on this topic here.

The Dangers of Hot Bolting

Dec 6, 2021

By: Alireza Zandi Karimi, Applications Engineer, Triangle Fluid Controls Ltd.

Hot Bolting
Hot bolting is the practice of sequential removing and replacing of bolts on a bolted joint (e.g. flange, heat exchanger, manway, etc.) while the joint assembly is under reduced operating pressure. This practice is potentially hazardous, and the utmost caution, therefore, needs to be exercised and carried out while under permit and controlled conditions. In many documented accidents where hot bolting has failed, there have been fatal casualties, fire, explosion, and loss of equipment and plant.

Investigating the root cause of various hot-bolting incidents shows a similar pattern: Loss of bolt load caused by a difference in thermal expansion rates between the bolt material and the flange material caused a leak at a bolted joint assembly and hot bolting was ordered to address the issue.

Typically, in hot-bolting accidents, the safety of the joint is being compromised because a few points are possibly overlooked:

  • Bolts have a small capacity to compensate for the “travel” when being stretched. Using devices such as flange springs allows for more bolt travel while maintaining bolt load during thermal cycling hence why they can help address these types of differential thermal expansion problems.
  • Using outdated bolt tightening methods, using non-calibrated torque wrenches, calculating wrong torque values, and using the wrong K Factor can all contribute to failure in any application. However, in the case of hot bolting, normally the fact that the lubricant under the bolts and on the thread dries out is not taken into account. A dried-out anti-seize does not have the same K Factor as a wet one. Using a wet K Factor on a dry joint in torque calculation may result in a lower actual load on the gasket than the target load due to differences in K Factors.
  • The strength of a bolt heavily depends on the temperature, and it decreases when the bolt is heated. This can result in breaking a heated bolt at much lower stress than that expected at ambient temperature causing major problems.

Understanding the factors affecting the joint assembly during hot bolting is key to minimizing the risk. Hot bolting should be carried out on depressurized equipment. The goal is to loosen and remove one bolt at a time , reapply the lubricant ensuring that the proper K Factor can be used in the calculation, then reinstall it (or use a new bolt) and retighten it to a specific target torque. It’s important to conduct a thorough analysis before hot bolting to make sure that enough travel in the joint can be achieved, and the target load can actually be obtained in all conditions.

Follow our Durlon® Gasketing Bolt Tightening Work Sheet and watch our step-by-step gasket installation video to further your knowledge of best maintenance practices.

DFT Silent Check Valve FAQs – Part 1

Aug 10, 2021

By: Bruce Ellis, Inside Sales Consultant at Triangle Fluid Controls Ltd.

As the Canadian master distributor for DFT® silent check valves, we experience quite a volume of questions regarding their function and capabilities. So we have decided to list the most common “Frequently Asked Questions”.

What series can be used on the discharge of a reciprocating compressor?

The best choice for this application is the PDC. Its unique design has a pulse dampening chamber that holds the disc steady in a pulsating flow. The PDC is also self-sizing which means it will function properly with different pressure and flow rates. This will not affect the performance or longevity of the valve. Note it can only be used with media in a gaseous state.

Can a particular valve be used in the vertical downflow orientation?

All DFT valves can be used in the vertical downflow position. This is due to the spring-assisted axial flow design of the valves. It is however important to know the head pressure involved to be sure the valve will close fully.

How low of a cracking pressure is available as a general rule?

As a rule, the lowest cracking pressure available for a DFT valve is 0.10 psi.

Is NSF-61 certification available for any DFT valve?

Currently, DFT valves are not NSF-61 certified for potable water.

What valve do you have that will work for a large range in flow?

DFT valves are not designed to work with a wide flow range. An axial flow valve is made to work properly at a specific flow with minor variances. A wide range of flow can cause the valve to chatter in a low flow situation if not designed for it. This can cause chattering and excessive wear to the valve. This will result in a shorter life span and premature failure. Please see our blog on valve sizing for more information.
We will be posting more FAQs in the near future. If you have a question, ask us here…it may get featured in the next round!
Bruce Ellis is an Inside Sales Consultant at Triangle Fluid Controls Ltd. He may be reached at or 613-968-1100.

How to trouble-shoot gasket leaks

June 18, 2021

By: Samantha Harrison, QA/Applications Specialist

gasket leak
There is nothing worse than being woken up in the middle of the night because of a leak in your piping system… and more often than not, gaskets get the blame!

Application leaks can be dangerous and expensive but at the same time, preventable. Unforeseen expenses due to loss of production, increased maintenance costs, and fines, could be devastating to a company.

Leaks caused by gasket failures can happen for a variety of reasons:

  • Under compression
  • Over compression
  • Uneven compression
  • Re-usage of gaskets
  • Chemical Attack

Let’s take a step back and talk about the mechanics of bolting; where a force is applied thru the flange to create a seal. This will compress and densify the gasket, reduce porosity, create a sealing barrier at the gasket ID, and will prevent fluid from penetrating and degrading the gasket.

Examples of Gasket Failures


What to look for:

  • Extrusion of gasket from the flange
  • Irregular-shaped gasket
  • Inward buckling of Spiral Wound Gaskets that contain inner rings
  • Imprints on the centering rings

What to expect:

  • Reduced gasket contact area causing the gasket to crush toward the ID
  • Fluid “pooling” around the ID which can lead to deterioration of the gasket
  • Damaged flanges


  • Plant Wide Bolting Procedure as referenced in ASME PCC-1
  • Gasket Torque Values based on the type of gasket material being used

Under tightening

What to look for:

  • Little or no flange serration marks
  • Little change in gasket thickness after being compressed

What to expect:

  • Fluid to penetrate gasket ID leading to deterioration of gasket
  • Gasket Blowout
  • Gasket Leakage


  • Plant Wide Bolting Procedure as referenced in ASME PCC-1
  • Changing bolting material

Re-use/Double Compression

What to look for:

  • Multiple compression lines/double patterns

What to expect:

  • Gasket Leakage


  • Stop the re-use of gaskets

Chemical Attack

What to look for:

  • Gasket Cracking
  • Softening of Material
  • Tearing
  • Erosion of Material
  • Uneven material discoloration

What to expect:

  • Gasket Leakage


  • Review chemical compatibility
  • Updating storage visual aids to identify different types of gasket materials
  • Improve storage requirements

It is important to always contact the gasket manufacturer to ensure the right gaskets are being used in each application.

If there is any confusion about required information for your application, please fill out our Gasket Application Data Sheet so we may further assist you.

Why Durtec?

Mar 30, 2021

By: Samantha Harrison, QA/Applications Specialist

There’s a buzz in the sealing industry about our Durtec® gasket. So, what’s a Durtec®, you ask? Very simply, it’s the combination of a corrugated metal gasket and a Kammprofile, on steroids! The Durlon® Durtec® is the next-generation semi-metallic gasket featuring a corrugated profile, based on our proprietary machined core, allowing for a tighter seal at lower bolt loads and zero retorquing.

The Durtec® gasket is universally used in a wide range of applications, including high-temperature applications (ETG configuration), aggressive chemicals (PTFE facing), vibration, and severe cycling applications where previous spiral wound gaskets were used and proven problematic. What makes the Durtec® so special is that it has excellent sealing features; a key factor when you have applications that are not easy to get to or are in remote field applications.

So, let’s review the many advantages of using a Durlon® Durtec® and why it is referred to as the universal choice for all your sealing needs:

  • API 607 4th edition Fire safe Certified, with zero leakage
  • Excellent Blow Out resistance due to the machined core
  • Cost-effective because it can be resurfaced, if not damaged
  • Can replace both Spiral Wound and Kammprofile gaskets, improving longevity and reducing inventory by consolidation
  • Seals with a lower bolt load compared to Spiral Wound and Kammprofile gaskets due to our proprietary machined core, resulting in lower overall fugitive emissions

With our various Durtec® gasket configurations, we can offer many sizes, types, and material options:

  • We can manufacture standard ASME, DIN, JIS, and BS EN sizes as well as Non-standard sizes up to 157” (4m) in diameter.
  • The standard core material is 316LSS but can be manufactured for almost any metal including 304SS, 317SS, 321SS, 347SS Inconel 600/625/750/800, Hastelloy C276, Alloy 20, Monel, Duplex 2205/2507, Nickel 200, Titanium, Zirconium and many other materials upon request, readily available or on-hand.
  • Our Standard facing material is super-inhibited flexible graphite that meets or exceeds Shell Specification MESC SPE 85/203, extending the upper operating temperature from 850ºF (454ºC) to 1022ºF (550ºC). Alternate facing materials are available upon request such as Durlon® 9000 & 9600 (for aggressive chemical applications), and our ETG (Extreme Temperature Gasket) series & HT1000® for high-temperature applications.

So, if you’re an engineer, pipefitter, plant, or maintenance manager, you can benefit from choosing a Durlon® Durtec® gasket for any suitable application. If you’re still uncertain, send us an email with the application data and we will review it and determine which Durtec gasket configuration is best for your sealing needs.

Gasket Thickness

Feb 10, 2021

By: Samantha Harrison, QA/Applications Specialist

Is thicker better? Well, when talking about gasket thickness it may not be. Depending on the type of gasket material being used, the size of the gasket, application parameters, and flange condition can affect the gasket thickness needed for your application.

Metallic and Semi-Metallic Gaskets

The thickness of metallic and semi-metallic gaskets is important for two reasons: constraints during manufacturing and handling of material. For example, a constraint during manufacturing could be that the gasket is too thick for the machine, while a flimsy, thinner gasket can become a handling issue.

Soft Gaskets

The pressure-temperature rating of a soft gasket is affected by the thickness. When a gasket is thicker, it will have a lower pressure-temperature rating compared to a thinner gasket. For example, a Durlon 9000 1/8” gasket has a lower pressure-temperature rating than a 1/16” Durlon 9000 gasket. It is always important to check PXT charts when selecting a gasket material.

When choosing a soft gasket, the flange condition will need to be taken into consideration. The thickness must be able to conform to flange irregularities such as flange damage, flange warping, uneven flange surfaces, etc. It is always important to reference PCC-1-2019 to determine if your flange condition is within tolerance.

Advantages Thick vs. Thin Soft Gaskets

Thin Gaskets (1/16” or thinner)
  • Higher blowout resistance due to smaller surface area exposed to internal pressure
  • Lower leak rate due to through-gasket permeation
  • Better creep relaxation allowing better torque retention
Thick Gaskets (1/8” or thicker)
  • Ability to fill in flange irregularities (dependent on gasket thickness and gasket compressibility)
  • Closure of leak paths between gasket and flange surface
  • Tolerance to flange misalignment
Common Recommended Gasket Thicknesses
  • Standard Raised Face Flanges in as-new condition will typically follow these configurations
      1/16” (1.5mm) gaskets up to 24” (600mm) nominal diameter
      1/8” (3.2mm) gaskets greater than 24” (600mm) nominal diameter
  • Standard Flat Face Flanges
      Utilize 1/8” (3.2mm) gasket thickness due flat face flanges typically have less rigidity
  • Non-standard pipe flanges i.e., glass-lined steel or plastic
      Utilize 1/8” (3.2mm)
  • Large equipment flanges
      Utilize ¼” (6.4mm) gaskets due to uneven flange surfaces

Please contact your gasket manufacturer to determine the proper thickness needed for your application.

Thermal Cycling Effects on Valve Operation

Jan 21, 2021

By: Bruce Ellis, Inside Sales Consultant at Triangle Fluid Controls Ltd.


What is Thermal Cycling?

Thermal Cycling is the process of alternately cooling & heating material and is often used in manufacturing environments to enhance the material’s properties.

Wafer Check Valves

When a wafer valve is placed in an application that has a wide range of thermal cycling or is exposed to prolonged periods of high temperatures, other system components may be affected. Exposed studs that span from the outside of the flanges on either side of a standard wafer valve, will elongate and can lead to a decrease in bolt load on the gaskets. This will cause the gaskets to leak.

One of the most recent products offering from DFT® is the TLW® (Tapped Lug Wafer valve). This valve is based on the proven wafer designs of the ALC® and WLC® and has many of the same trusted benefits and features, just in a lug style valve.

The TLW® axial flow spring assisted check valve has a one-piece body design that is lightweight and compact. It meets the API 594 face to face dimensions and can be installed in both horizontal and vertical flow applications. The big difference between the standard wafer style valve and the TLW is the tapped design doesn’t have exposed studs which protects the studs from the negative effects of thermal cycling and reduces the opportunities for gasket failure due to stud elongation and relaxation. This style of valve is also suited to fire-safe applications where there is a need to protect bolt exposures as each end of the valve is bolted to the flange similar to the way a flanged valve is.


So, when thinking about valve applications involving high temperature or with a wide range of thermal cycling it is important to consider the valve type itself. The DFT® TLW® might be just the valve you want to use.
See the line-up of DFT® Silent Check Valves here.
Bruce Ellis is an Inside Sales Consultant at Triangle Fluid Controls Ltd. He may be reached at or 613-968-1100.

Chett Norton Appointed to the Role of General Manager, Durabla Canada Ltd.

December 28, 2020

Chett Norton


Chett Norton Appointed to the Role of General Manager, Durabla Canada Ltd.

“Chett first started with Durabla Canada in 2002 on Inside Sales. After a couple of years, he explored other opportunities in the USA, but eventually came back to Canada about 8 years later. I stayed in touch with Chett through that whole time as I always said that he would eventually replace me as the Durlon gasketing technical expert. Lucky for us, I convinced Chett to come to Triangle Fluid Controls in 2012 as an Applications Engineer and then in 2015, he was promoted to Engineering and QA Manager. Chett is probably one of the most hands-on team players that I’ve ever had the privilege of working with and to that extent, Chett has been involved in a vast array of projects and activity at TFC since 2012. With his enthusiasm, drive, professionalism, and ability to develop and grow, this next challenge as General Manager is the perfect fit for Chett, our companies, and Durabla Canada’s long-term stability.”

“Durabla is the name that started everything for us and Durabla will continue to be the name that stands the test of time. Durabla Canada will continue to play an integral role in the health and viability of our global gasket brands and under Chett’s leadership, we’ll get there together.” Mike Shorts, President, Triangle Fluid Controls Ltd.

Welcome Chett to the Durabla team!




Check Valves – Back to the Basics – Part 2

Dec 3, 2020

By: Bruce Ellis, Inside Sales Consultant at Triangle Fluid Controls Ltd.

What is meant by check valve sizing?

Sizing a centre guided valve is not difficult. Along with the pipe size, pressure class, and type of valve required (flanged, wafer, etc.), users need the actual working pressure, flow rate, media type, temperature, and the specific gravity of the media. It may be as simple as building the valve with a lighter spring to allow the valve to fully open. In order for the valve to reach the full open position, it may need a lift limiter to reduce how far the disc travels. When the valve is 100% open, it will be stable in the flow and will result in reduced premature wear and failure by eliminating the effects of chatter. It is very important to remember; these valves are designed to the actual flow values and not to the line size. A properly sized valve will be in either the full open, or closed positions.

Why size a valve?

Benefits of using a properly sized and positioned silent check valve:

  • It can protect a system from costly failures and down-time of a production facility.
  • The valve life span can be greatly increased by reducing the risk of parts breaking off and damaging equipment downstream.
  • It protects the pumps that are upstream by not allowing backflow which can severely damage the pump as it can spin in the reverse direction.
  • It leads to better pump and compressor protection.
  • It results in less piping vibration.
  • There is a reduction in Water Hammer issues.
  • It will work in the vertical down flow direction.


Return on investment

Initial “sticker shock” for a sized valve, in many cases can be scary, so we need to ask ourselves a few questions:

  • How long does the off-the-shelf valve last?
  • What does it cost to change it?
  • How much revenue is lost while it is being replaced?

Replacing a valve can be quite costly based on the effects of lost revenue, wages, and the cost of the replacement valve. The price of an off-the-shelf valve may be attractive, but what is the real cost of ownership? If a sized valve costs five times as much but lasts five times as long, consider how these affect your financial balance given maintenance costs and lost production.


While there are applications where double-door and swing check valves operate properly and are required, it is not true that these and other off-the-shelf valves are the only solutions. In any application where check valves are being used, having the correct valve installed could enhance the performance and extend the lifespan of the piping system, affecting the financial balance when adding maintenance costs and lost production. This translates into more value and overall, long term cost savings.
See the line-up of DFT® Silent Check Valves here.
Bruce Ellis is an Inside Sales Consultant at Triangle Fluid Controls Ltd. He may be reached at or 613-968-1100.

The 5 W’s of Isolation Gaskets

Oct 8, 2020

By Chett Norton, C.E.T.


Isolation gaskets may seem to be a complicated subject when trying to determine what is required and whether you require them at all. When looking at possible isolation gasket application requirements I like to put on my “Sherlock Holmes” hat and asks myself the following 5 W’s – What, Why, Where, When, and Who.


Let’s begin with what are isolation gaskets? Isolation gaskets are exactly as they sound, they isolate flanges from the flow of electrostatic charges through the pipeline and or can separate dissimilar metals which can cause galvanic corrosion. For galvanic corrosion to occur you need an anode (metal 1), cathode (metal 2), and an electrolyte or carrier such as water to help allow the transfer between the two metals. The anode will be the sacrificial material and will corrode at a much higher rate than the cathode; in some cases, the cathode material may even stop corroding completely. The further the two metals are apart on the galvanic corrosion chart (Most Noble – Cathodic to Least Noble Anodic), the higher the potential for corrosion (See Figure 1 – Dissimilar Metals Chart below).



Durlon® iGuard isolation gaskets are commonly sold in kits that are composed of a gasket, a set of insulating sleeves for the bolts, 2 sets of insulating washers, and two additional sets of steel washers. (See Figure 2 – Isolation Gasket Kit Components). The gaskets themselves can be either full face (Type E), ring style (Type F) or RTJ (Type D) and are offered as a carrier ring such as phenolic, neoprene faced phenolic, Silicone Glass G-7 or Epoxy Glass G-10 or G-11 and comes standard with a Viton sealing element but has other sealing element options such as PTFE, nitrile or EPDM. Additionally, the gaskets can also be composed of sheet material such as Durlon® 8400, 8500, or 9000 (1/8” thickness recommended) which have excellent dielectric breakdown properties (371 – 406v/mil). The standard offering for isolating sleeves is mylar, Phenolic for the isolating washers, and zinc-plated steel washers. Additional materials for the isolating sleeves and washers are available upon request. See Durlon® iGuard technical datasheet here.




Galvanic corrosion is a big problem because it can lead to a rapid metal loss in piping systems and tanks. It can cause leaks or even failures which can have catastrophic consequences for plant personnel safety and the environment.


Isolation gaskets are found anywhere that you have flanges that consist of dissimilar metals such as cast iron to carbon steel or even aluminum to stainless steel for instance. The isolation gasket kits create a dielectric break which generates cathodic protection for both above and underground piping where metal components that are in contact which each other in the bolted flange joint assembly. Isolation gaskets are commonly used in the petrochemical industry, oil & gas, and marine/offshore applications that deal with high chlorides such as seawater.


Whenever galvanic corrosion or electrical isolation is a concern in the piping system. It should also be noted that there are additional benefits to using isolation gaskets (carrier ring with sealing element) such as:

  • Isolation gaskets seal at very low stress, perfect for low torque requirements
  • Installations that have frequent assembly and disassembly, such as pressure test stands. These can be reused multiple times due to their resilient double-ogee sealing element (normally it is not recommended to reusing gaskets).


    Engineers, plant & maintenance managers, pipefitters, and installers can all use the benefits of Durlon® iGuard isolation gaskets for plant piping protection in both new design and existing piping systems.
    So, if you are wondering if you need an isolation gasket for your application, there is a good chance you do, but if you are still not sure……give us a call and we can help guide you through the isolation gasket material selection process.
    Click here to learn more about Durlon® iGuard Isolation gaskets kits.

    Check Valves – Back to the Basics – Part 1

    September 25, 2020

    By: Bruce Ellis, Inside Sales Consultant at Triangle Fluid Controls Ltd.

    Many informative articles have been written about check valves in the past… with that being said, let’s take this discussion “Back to the Basics”. Check valves, or one-way valves, are designed to stop backflow and ultimately, to protect pumps & compressors. They are available in several styles and sizes; from 1/8” to as large as may be required.

    Check valves are found in many industries, and with various types of media, ranging from municipal water to mining and natural gas.

    The 3 most common types are Swing Check Valves, Double-Door Check Valves, and Silent Spring-Assisted Axial Flow:

    1. Swing Check Valves

    Generally speaking, this is probably the most common check valve in use today and is a full-port design, meaning the disc, when fully open, is out of the flow stream. This style of check valve is a good choice in applications that have a high percentage of solids and a lower on/off cycle count. Due to the travel distance of the disc, swing check valves close slowly. This causes the last push of reverse flow to slam the disc closed, resulting in a huge pressure spike, causing Water Hammer*.
    *A pressure surge when a fluid, in motion is forced to stop or change direction suddenly, causing a pressure wave in the pipe. This pressure wave can cause major problems, from noise and vibration to pipe collapse.


    2. Double-Door Check Valve

    This valve is similar to the swing check and a little better in terms of closing because of the coiled springs that assist the two cantilevered doors in closing more quickly. It has been proven time and time again that this is not the best choice when faced with Water Hammer though they will perform better than a swing check valve. Generally, this style of valve is considered an off-the-shelf commodity valve with little customization available.


    3. Silent Spring Assisted Axial Flow Check Valve

    These full flow valves typically incorporate a centre guided stem-disc assembly along with a compression spring. This means the disc stays in the flow stream and the media flows around it and doesn’t require manual or automated assistance to operate. When the pump is running, the valve is open; when the pump shuts off, the valve closes slightly before the reversal of fluid flow, due to the compression spring force acting on the disc, which nearly eliminates Water Hammer.

    See the line-up of DFT® Silent Check Valves here.
    Most requests for check valves take into consideration the line size and pressure class alone, as media pressure and flow can vary dramatically where pipe designs are oversized for future concerns or undersized due to lack of or incorrect information. This is not always the best way when deciding which style of valve to use in a system. Other things to consider are: working pressure, flow rate, the specific gravity of the media, and temperature. An analysis of the system design is highly recommended.
    It is necessary to understand why valves fail, and the root causes. The most common failure is due to excessive wear of the internal parts of the valve. Springs, discs, and stems wear prematurely by not being held steady during operation. When the disc is not stable due to insufficient flow to hold it in the full-open position, chattering can occur.
    Bruce Ellis is an Inside Sales Consultant at Triangle Fluid Controls Ltd. He may be reached at or 613-968-1100.
    Watch for Part 2 “Check Valve Sizing” coming in December!

    Choosing the Right Gaskets for FDA Applications

    Aug 28, 2020

    By: Samantha Harrison, Lab Testing Technician/QA Assistant

    The Food and Drug administration (FDA) comprises of a very broad and complex area of regulations. While there is no specific required certificate for FDA approval, it is up to the manufacturer to read and review the regulations to ensure their material/product meet that particular criteria.

    There are multiple ways a gasket can conform to FDA regulations.

    • GRAS (Generally Recognized As Safe) – Materials adequately shown to be safe under the conditions of its intended use, or unless the use of the substance is otherwise excepted from the definition of a food additive. Eg. PTFE or 316SS.
    • Existing FDA Regulations – Material ingredients that are listed as compliant in the applicable FDA regulations.
    • FDA FCN (Food Control Notification)– These are new materials that are not covered by either of the above but can be submitted to the FDA under a FCN.

    PTFE and Virgin PTFE gaskets are commonly used in FDA applications. Filled PTFE gaskets can conform to FDA regulations if the filler or fillers, colouring agents, etc., are considered as GRAS or if the fillers and colouring agents are complying with another regulation. If PSA (Pressure Sensitive Adhesive) is used, it will also need to conform to FDA regulations.

    Elastomer gaskets are another gasket material that will conform to FDA regulations (For eg. Durlon® 8500). This gasket material is commonly used in both raised-face and flat-faced flanges (in which the available compressive load is low).

    If any adhesives are used to perform a sealing function, they will need to meet the requirements mandated by the FDA (21 CFR 175.105).

    When inks are used to mark gasket material, it must follow the same FDA (21 CFR 175.105) criteria and all ingredients used in the branding ink must be acceptable for direct contact with food and pharmaceutical products.

    Some applications are more complex/difficult and require the use of systems that are over and above the FDA regulations, such as the National Sanitary Foundation (NSF), U.S. Pharmacopeias (USP) and 3A.

    It is always important to contact your gasket manufacturer to confirm your gasket conforms to FDA regulations.