January 26, 2017

By: Chett Norton, C.E.T and Stephanie Jouppien

 

Figure 1: Pitted flange with steam cuts. Photo courtesy of Slade Inc.


Imperfections on flange faces happen. With regular maintenance and removing old, stuck-on gasket\debris, flanges with scratches, pits, dents and dings are a common site in many a plant. With more and more companies adopting low emissions business practices, can damaged flange surfaces seal to meet environmental compliance?

 

In the fluid sealing world, we know that flange surface is directly related to sealability and sealability is directly related to environmental compliance. As 85% of all known flange gasket failures are installation related, installers must take extra care when sealing damaged flange faces. Acknowledging the importance of proper gasket installation, we’ve compiled a list of 10 steps and considerations for diagnosing and overcoming flange damage.

 

10 Steps to Sealing Damaged Flange Surfaces

 

    1. 1. Get an updated copy of ASME PCC-1

      ASME PCC-1 is unarguably the post-construction code bible of bolted flange joint assemblies (BFJA) in North America and following their published guidelines is best practice for bolting assembly procedures. A big benefit in using PCC-1 when sealing damaged flange faces is that it addresses the issue of working with imperfect flange faces and determines permissible amounts of damage that can still work as part of a BFJA and maintain an effective seal. Keep an eye out for updated versions of PCC-1 as fugitive emissions regulations become stricter.

 

  1. 2. Understand how a gasket & flange work together as part of a BFJA
Figure 2: Bolted Joint Flange Assembly. Photo: Guidelines for Safe Seal Usage, Flanges and Gaskets. ESA/FSA Publication No. 009/98

 

The gasket is meant to create and maintain a static seal between two stationary, imperfect surfaces, containing a variety of liquids or gases under various service conditions. The surfaces or flanges must significantly compress the gasket to ensure a tight seal that has uniform pressure across it, despite any physical damage, like pits or dents. Mating flanges connected by a sealing device have serrations (roughness) on the faces that are meant to “bite” into the gasket material, effectively holding the gasket in place as it is compressed between the two flanges. As the compression happens, forces try to push the gasket material outwards. By holding the gasket in place, the installer is able to compress the seal and achieve desired tightness. The hole in the centre of the ring gasket will compress inwards slightly but remain open to allow media to pass through the pipe.

 

  1. 3. Take apart flange and assess for damage

When replacing gasket material in a BFJA or performing maintenance, pay attention to the flange face. Note any visual defects or damage – marks, scratches, dings or anything that changes the serrations on the flange face that can affect the flange’s ability to “bite” into gasket material. If so, reference PCC-1 for the maximum allowable defect depth and determine if the flange is suitable for service.

 

  1. 4. Identify a compressible gasket material that can fill imperfections

There is a high probability that damaged flanges could be a factor in BFJA failures. Warped and damaged flanges need to have imperfections filled by a compressible gasket material that can “bounce back” or recover with the flange and prevent leak paths from forming. Because this is widely known, installers believe installing a thicker gasket will solve the problem. However, what they do not take into account is that the thicker the gasket, the more creep will occur and paired with the inevitable decrease of force on the gasket, a gasket failure could result.  The more that creep relaxation occurs, the higher the chance of a blowout.

When using smooth face finishes, such as those usually found in machinery or flanged joints other than pipe flanges, it is important to consider using a thinner gasket to lessen the effects of creep and cold flow. It should be noted, however, that both a thinner gasket and the smooth finish, in and of themselves, require a higher compressive force (i.e. bolt torque) to achieve the seal.

Durlon low emission gaskets for damaged flanges


Durlon PTFE
–compressible gaskets with low creep properties suited to a wide range of service conditions and aggressive chemicals

Durlon ePTFE – highly compressible and versatile biaxially stretched PTFE product that conforms well in worn flanges and can handle a wide range of aggressive chemicals

Durlon ePTFE with metallic core – Durlon Durtec gaskets are virtually uncrushable under recommended loads and are an excellent low-emissions sealing gasket, paired with the conformability of ePTFE on both sides to suit imperfections on flange faces

Durlon SWGs (spiral wound gaskets) – winding density can be altered to allow conformability of SWGs

 

  1. 5. Determine correct thickness

A general rule of thumb for gasket thickness, is that if your flanges are in good condition and under 10” NPS the industry standard is to use 1/16” thickness. For flange sizes 10” NPS and larger the recommended thickness is 1/8”. If a previously installed PTFE gasket is removed and the serrations of the flange protrude through the material, this indicates that perhaps the gasket material being used is too thin and a thicker material should be used. In most industrial sealing applications, 1/32” is the minimum thickness that should be used, depending on the roughness or extent of damage on the flange face.

Figure 3: Gasket thicknesses; Left – 1/16″; Right – 1/8″

 

Note: Regardless of thickness, all of the other standard gasket qualifications must be met including bolt load, chemical resistance, working temperature/pressure ranges, material recovery, systematic thermal cycling, etc.

 

  1. 6. Take extra time installing & use proper torque values

It’s best to take a little extra time when installing a gasket between damaged flanges as improper installation causes approximately 85% of flange gasket failures and can greatly impact plant safety and piping structural integrity. If a single void is left unfilled, the gasket buckles or pinches, a leak path will be created. Be sure the reference the correct torque values by flange size and gasket style/class. Torque values are made readily available by the gasket manufacturer; Durlon torque values can be found on pages 49-53 of the Durlon Gasket Manual.

 

  1. 7. Add extra passes to bolting “star pattern” in assembly procedure

As an installer begins incremental tightening with the standard “star pattern” bolting assembly, additional passes will ensure the gasket is flat against the flange face. Concentration points forming over pits and marks will increase stress in those areas and possibly crush the gasket in certain places. Extra passes are especially important on worn flanges when serrations don’t “bite” into the gasket and hold it in place. For a printable Bolt Tightening Worksheet, click here.

 

  1. 8. Re-torque

The gasket will inevitably relax, with the majority of creep-relaxation happening between 4-20 hours after the initial installation and must be re-torqued. This is a step that is frequently missed in many day-to-day gasket installations, in part because downtime is not an option for many. An even bigger issue, is when those installers fire up a system right away and re-tighten when the system is hot. This is known as hot-torquing and is not recommended. When a soft gasket material, such as compressed non-asbestos is hot-torqued, the material can crack as it becomes brittle when elastomer based material comes into contact with elevated temperatures.

 

  1. 9. Keep a record of damaged flanges and record leak rates

Keep a detailed record of which flanges in your systems are damaged, so that the same installation procedure can be used.

 

  1. 10. Replace gaskets or flanges when necessary

In many cases, an imperfect flange won’t be cut off and replaced, but when sealing with environmental compliance in mind, it is best to ensure that leaks are properly identified, recorded and dealt with. In some cases, this means replacing gaskets more frequently, especially if stress concentrators over dents/scratches are causing issues. It is best practice to not re-use gaskets unless direct application and user experience suggests it is safe to do so.

 

Main Takeaways

 

Slowing down and properly assembling a flange gasket connection can help companies meet environmental mandates by reducing emissions in BFJA’s. Be sure to properly assess physical flange damage on a flange surface and reference PCC-1. The imperfections seen may be well within the recommended guidelines for use by ASME. If you do have some damage to contend with, consider using a thicker, more compressible gasket material to fill imperfections, effectively preventing leak paths. Become familiar with proper bolt-up procedures and understand how much compression is needed if the switch is made to a thicker, softer material. Avoid firing up any systems immediately after installation and observe and record how the new BJFA performs compared to others.

For sealing solutions for damaged flange surfaces or detailed instructions on low emissions sealing, fill out this form.

 

 

You may also like…

Can Low Gasket Load Applications Meet Upcoming Fugitive Emissions Requirements?

What Does Gasket Installation Really Cost Your Plant?

How Long Will A Bolted Flange Gasket Last?



Durlon ® Sealing Solutions manufactured by Triangle Fluid Controls Ltd. is featured in the inaugural edition of the Fugitive Emissions Journal, December 2016.

Read the full article here.

 

 



Triangle Fluid Controls Christmas lights


Triangle Fluid Controls Ltd. (TFC) is delighted to announce that they have donated a newly created holiday addition to the City of Belleville’s annual Christmas Lighting Display. Along with a Santa-level sponsorship, a team of TFC elves worked diligently through the summer months to come up with a festive light display to share with thousands of local residents.


The annual lighting launch officially kicked off the holiday season on Friday, November 18th beginning at 5:45 PM at Jane Forrester Park in Belleville’s South-East end (near the city’s pier), and will remain lit through to the New Year.For a number of years, TFC has been happy to spread Christmas cheer throughout hometown Belleville, Ontario, by sponsoring the much-loved holiday creation that delights the young and young-at-heart and has become a beloved community tradition. The Christmas Lighting Display, originating from tragic events over 50 years ago, was built by a grieving family and epitomizes the true meaning of Christmas. Now operated by the City of Belleville, it is visited annually by thousands.


Be sure to check out Belleville’s must-see Christmas Lighting Display at Jane Forrester Park from November 18 – mid January. For more information visit: https://www.belleville.ca/recreation/page/christmas-lighting-display

November 14, 2016

By: Bruce Ellis

 

It’s fall and for some, still warm – but it won’t be long until another heating season begins. Some facilities are already seeing the restart of boilers, and so, I’ve decided to address a cold weather issue that often arises with industrial steam and water boilers this time of year: they don’t start. Is there anything worse than a service call at 3 AM in January when the temperatures outside drop to -20°C? Once you have eliminated each component in your boiler as a possible culprit to boiler failure and it comes down to a check valve sticking open or closed in your system, it’s time for a replacement.

Each boiler is unique in the way it is designed and your choice in replacement will be somewhat dependent on the specifications your system requires. Whether you have a liquid, gas or steam boiler, this introduction to DFT Inc.’s three most common check valves for HVAC service is sure to get you warmed up to a replacement valve.

Note: DFT also manufactures check valves for use in large industrial boiler systems. A complete guide can be found here.

 

BASIC CHECK VALVE

Basic-Check-(1)

This proven check valve is suitable for a wide range of applications and is extremely versatile due to its ability to work at various pressures and temperatures. The Basic Check Valve can be made in different grades of stainless steel and is available from ¼” – 2 1/2” line sizes. The basic check can be used in installations requiring a CWP of 450-6,000 psi. DFT also manufactures the Basic Check with higher cracking pressures, from 2-40 psi. While the Basic Check is versatile, be sure to reference DFT Inc.’s full Catalogue for certain restrictions.

 

SCV CHECK VALVE

scv check valve canada

The most common check valve for use in steam applications, the SCV is also commonly used with liquid and gas. It uses the same trim as the Basic Check, in a durable body made of either 316 stainless steel, Alloy 20 or Hastelloy alloys with either FNPT or socket end welds. DFT SCV’s are available for ½”-3” pipe sizes and either 750 or 3,600 CWP. The SCV-R (Restrictor Check) is designed for higher cracking pressures than the standard SCV check valve. For a more simplified and flanged version of the SCV check valve, available in ASME Class 150 and 300, see DFT’s DLC check valve.

 

FBC CHECK VALVE

fbc check valve canada

If you have an existing system with limited space – check this little space-saver out. The FBC “insert wafer” check valve is designed to be installed between two flanges and uses the same proven technology as the Basic Check valve. Though small, the FBC is made to last with stainless steel construction and a well-protected spring, not to mention the FBC can withstand temperatures up to 232°C (450°F). The FBC check valve works with schedule 40 pipe in the most common sizes 1”-4”, pressure class 150/300.

 

DFT Check Valves Used Extensively in HVAC

The simplicity and durability of DFT Valves has been proven since the original design dates back to the 1940’s and remains unchanged to this day. The non-slam, spring-assisted design prevents  reverse flow and virtually eliminates water hammer in your system. All of DFT’s check valves are capable of water-tight shutoff, are easy to maintain, can be installed in any direction and are built to last. Our distributors and end-users tell us that “they last too long” and regularly comment on their unsurpassed design and efficiency. If you would like to learn more about DFT check valves for industrial steam, water or HVAC, let us know, we’re here to help.

 

Additional Resources

Design for Flexibility: Key Considerations to Make When Designing Fluid or Gas Flow Systems

DFT Check Valve Success Studies

Check Valve Application Data Sheet

 

 



Belleville, Ontario – September 29, 2016

9000N_single_above_DSC8621Triangle Fluid Controls Ltd. (TFC) the manufacturer of Durlon® sealing products, is proud to announce that the sanitary “white” version of its flagship product, Durlon® 9000N, has been successfully tested and certified to USP Class VI standards for use in the in the pharmaceutical and biotechnology industries. USP (short for United States Pharmacopeia) Class VI is a series of biological tests, requiring a product to show minimal to zero levels of toxicity, making it a suitable gasket material for use in medical devices and other applications where a ‘hygienic’ material is required.

Like the rest of Durlon’s PTFE material, Durlon® 9000N is FDA compliant, making it suitable for use in the pharmaceutical, chemical, food and beverage, and biotechnology industries. Offering USP certification among the Durlon® line of products, allows TFC to better meet the unique needs of its customers who span across a wide range of industries. For more information about Durlon® 9000N, please contact Triangle Fluid Controls Ltd.® at 1-866-537-1133, or info@trianglefluid.com.

Technical Documentation: Durlon® 9000N

 

 

 



Congratulations to Damon Wright, who has been promoted as TFC’s newly established Manufacturing Manager, announced August 17th, 2016.  The former Warehouse Technician joined the company in 2013, and quickly proved himself an asset to the global gasket manufacturer. “Damon has accepted any and all challenges thrown his way and has excelled at completing them. He’s a key contributor to TFC’s team and is greatly respected among our staff,” says Mike Boyd, TFC Plant Manager, who will in October transition to General Manager of TFC. Damon’s new responsibilities will include overseeing and controlling all aspects of plant production operations including costs, efficiencies, hiring, and improving on processes and procedures in order to meet organizational goals and consumer demand.

The restructuring of TFC’s management comes as a result of a number of internal managerial promotions within TFC and across its’ privately held sister companies. TFC is currently recruiting for a Warehouse Technician at its Belleville, Ontario plant. A full listing for the position can be found here, or by e-mailing dan@trianglefluid.com.

 

manufacturing manager

Belleville, Ontario – July 28, 2016

award

 

Triangle Fluid Controls (TFC) is pleased to award the 2016 Randy McKay Sales Award of Merit to Ryan Kelly, in recognition for his outstanding sales performance with TFC. The award was given to TFC’s Regional Sales Manager (RSM) whose territory had the largest year-over-year sales increase from 2015 – 2016 and was presented July 28 at TFC’s headquarters in Belleville, Ontario. “We are extremely pleased to award Ryan Kelly with the first ever Randy McKay Award of Merit,” said TFC’s President, Mike Shorts. “Over his short time with us, Ryan has showed immense passion and dedication to our team that has not only seen revenue growth in new markets for TFC but would make the award’s namesake proud.”

The award, created in memory of the late Randy McKay, TFC’s Central Canada RSM, was created by Shorts as a means of paying homage to his former employee. “Randy did a lot for TFC, was a stand-up individual, and somebody that I personally, learned a lot about sales from. After Randy’s passing in 2015, I knew I wanted to create an award in his memory and present it to his family.”

Also in attendance at the award ceremony, was Randy’s son Brock, representing the McKay family. Brock was also awarded a glass sculpture on behalf of TFC, for his father’s dedication to the company. “This place [TFC] meant a lot to him. It was inspiring to see someone who had such a passion for what they did,” remembered Brock.

The award included two pieces: an engraved glass plaque and hand blown glass sculpture made similar in shape, style, and colouring to TFC’s company logo. A second plaque will hang in TFC’s lobby with each year’s winner added to it. The making of the pieces, commissioned by a local glass blower in Prince Edward County, was completely documented and can be found posted online on TFC’s social media channels or by clicking here.

 

July 19, 2016

By: Chett Norton, C.E.T

 

Fugitive emissions are a red hot topic right now – and for good reason. With ever-increasing environmental awareness, leakage and how to prevent and reduce leaks should be on everyone’s mind. As a gasket manufacturer, it is Triangle Fluid Controls job to design, develop and educate end users on products that can help them meet upcoming low emission regulations.

Common class 150# flanges are well known as a stubborn culprit when trying to seal flanged connections – particularly 3” and 8” lines sizes.  In the case of 150# flange design, an installer cannot apply enough load to the gasket due to either bolting, flange or material constraints. Another consideration is that with full face (FF) gaskets, you are trying to seal about 2-3 times the area of a ring gasket for raised-face (RF) flanges. You might ask,

 

“If I can’t apply more load to the gasket, how can I increase gasket load stress?”

 

Although it is case-by-case scenario, you have two options:


1) Reduce gasket sealing area

2) Use a controlled swell gasket material to intensify gasket stress after installation

Continue reading to determine the best option for your application.

 

 

Option 1: Reducing Gasket Area

pressure

Reducing the gasket area is extremely effective and usually one of the easiest ways to increase gasket load, when not enough load can be applied to the gasket. Remember that Pressure= Force/Area, so if we can decrease the area, the pressure (in this case the seating stress) will increase. Specifically, the Durlon RCA (Reduced Contact Area) gaskets and Durlon PTFE Step Ring gaskets are designed based on this concept. Both types of gasket are fairly unique, even though they reduce gasket area so that the gasket stress is increased. Durlon RCA type gaskets are ideal for full face (FF) flanges and FRP piping that require a tight seal, however, they cannot handle high bolt loads generally required for fugitive emissions or critical sealing applications. The skeleton of the RCA gasket resembles that of a full face (FF) one, except a large portion of the non-critical gasket area is removed for optimal sealing performance.

Front View - FF vs RCADurlon 9000 Step Ring gaskets are like a ring gasket, except a portion of the sealing area is reduced by machining it on a CNC lathe from one piece of material. Traditionally, these type of gaskets are manufactured by laminating two gaskets of a thinner gauge and various size together with an adhesive. Aggressive chemicals, such as sulfuric acid, can quickly eat away at the adhesive after installation, which can lead to a premature leak path. PTFE Step gaskets are commonly found in sulfuric acid plants, and applications for PTFE Step Rings include 150# raised face (RF) (Floating) Lap Joint flanges, as well as MondiTM ductile iron sulfuric acid piping.

Step Gasket

 

Option 2: Controlled Swell Gasket Material

 

In cases where the gasket area is already minimal and cannot be changed by design, or if reducing the gasket area simply isn’t enough, selecting a controlled swell material is a great option. These types of material really shine in low load applications that involve oil and water. Once the gasket is installed, the material swells when it makes contact with oils, fuel or water, which increases gasket thickness. As the material begins to “swell”, the gasket starts to expand, exerting force in both directions, against the flanges. Imagine a Belleville washer being compressed: by design, it applies force in the opposite direction, over the entire gasket-media contact zone and not just the fastener point-load zone. In theory, this is what a controlled swell material is doing. Durlon DuraSwellTM 7760 is a prime example of how choosing a high performance sealing material can negate less than ideal gasket sealing loads and still achieve a tight low to zero emissions seal.

Model

 

Conclusion

 

So, can low stress sealing applications meet fugitive emissions requirements? My answer is absolutely. As always, I recommend contacting your gasket manufacturer and providing all of the necessary application details. This will allow a specialist to recommend the proper material and installation methods to ensure the best performing sealing device for your specific needs.

 

Until next time, stay safe out there, and keep the fluid between the pipes!

– TFC GasketGuru

 

 

Additional Resources

Durlon Duraswell 7760 Tech Sheet

TFC Ready to Help Canadian Energy Sector Reach New Emission Reduction Targets

What does gasket Installation Really Cost?

How long will a bolted flange connection last?

High temperature gaskets 101

Request A Quote

 

 



Durlon® introduces fresh products with tighter sealing capabilities at low pressures that can actually help to protect your industrial system.

 

Durlon® Sealing Solutions, a leading name in premium PTFE and semi-metallic gaskets, introduced its newest line of sealing technology, dubbed “Durlon® iGuard™” Flange Isolation and Sealing Kits. Conveniently packaged to contain all necessary components to tightly seal, electrically isolate, and effectively control corrosion of mating metallic parts, the end result is a greatly reduced risk of leakage or system failure in severe services such as gas, acids and other aggressive chemicals or media, ranging from cryogenic to high temperatures.

 

Each kit consists of a gasket, isolating and backing washers, as well as isolating bolt/stud sleeves. Gasket selection can be made from a wide variety of materials to best suit the sealing and performance needs of each application. In gaskets with phenolic or glass carrier rings, a “double-ogee” sealing element provides a reliably concentrated unit load on the flanges using the lowest torqueing conditions possible. Gaskets are available in four different flange facing types and are able to meet all international piping sizes and dimensional standards.

IGuard 9000 sm

      Pictured: Durlon® iGuard™ 9000.

Particularly useful for industry professionals in the Oil & Gas, Chemical, Water/Wastewater and other process industries, the user simply lays the sealing element on the flange face. As the sealing element is compressed against the flange, any tiny gaps between the mating flange and sealing element become filled. This movement provides the end user with a tighter seal, despite potentially lower pressures, with the added ability to isolate parts. The tri-directional movement of the sealing element provides better elastic recovery over time, as bolt loads relax and pressure/temperature cycles occur.

 

For more information on Durlon® gasket materials available for the iGuard™ flange isolation and sealing kits, technical documentation, product availability and kit specifications, contact Triangle Fluid Controls Applications Engineering department at tech@trianglefluid.com or visit www.trianglefluid.com.

 

 

 



Gas problems? No need to raise a stink!

May 31, 2016
By: Bruce Ellis

 

If you work in natural gas processing and refrigeration, chances are you know the demands of storing and transporting gas. Compared to fluid sealing and discharge, the media flow isn’t steady, instead, gas “pulses” (through a pipeline) from a reciprocating compressor. This pulsating flow created by the compressor causes the discharge valves to chatter, and while the sound may not be high on your daily list of concerns, the resulting wear or damage to your check valve and downstream components can eventually lead to costly headaches. With the ever increasing global demand for natural gas, issues with check valves and piping systems after installation of a reciprocating compressor is something we see occurring more frequently.

 

The problem: an ineffective check valve for gas applications.

 

With natural gas production set to double by 2017 (U.S Energy Information Administration), producers must ensure that their systems are designed with quality parts. While sourcing quality equipment can be time consuming and result in large up-front costs, having the right parts installed in your system will ensure less time spent on maintenance, downtime, and fewer future costs. Ineffective discharge valves are more likely to create issues and suffer undue wear than using a check valve built with a damped design to control the valve’s moving parts. It’s not unheard of to learn of parts that have broken off of valves, damaging downstream components which may cause system failure.

 

 

Built specifically for gas applications, DFT’s PDC check valve is a world-class solution found in oil refineries, gas pipelines, as well as storage and pump stations. Its pulse dampening chamber keeps the disc stable and in place (see below video). The PDC is also self-sizing, meaning it can handle different pressures and flow rates, without creating an issue or suffering undue wear. This flexibility extends the life of the valve. As an added benefit, the PDC can protect downstream equipment from damage that could be attributed to other types of valves if they fail.

 

The PDC check valve is manufactured to meet industry standards and can be built and tested to meet your company’s specifications. Available in various sizes and pressure classes, it can be manufactured using various metals, and is available with flanged, butt weld, or RTJ ends. If you would like to discuss your design needs, call us toll-free at 1-866-537-1133 or email bruce@trianglefluid.com.

 

Dimensions:

PDC dimensions

Additional Resources:
DFT Catalogue
Valve Data Sheet


Do you have an interesting idea for an industrial blog topic you would like to see covered? E-mail stephanie@trianglefluid.com.