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Sizing Semi-Metallic Gaskets When Replacing Soft Gaskets When replacing soft gaskets with semi-metallic gaskets, it's important to understand the sizing differences and considerations. The following guidelines provide suggested dimensions based on experience to help you choose the appropriate non-metallic gasket size to replace a soft gasket. These sizings are not mandatory but serve as useful recommendations. 1. When Flange Dimensions Are Provided If the customer provides the dimensions of the flange, the following guidelines can be used to determine the appropriate gasket size: Gasket Inner Diameter (I.D.) : The inner diameter of the gasket should be the bore size of the flange plus a minimum of 1/8". Gasket Outer Diameter (O.D.) : The outer diameter can be up to the bolt hole circle diameter minus one bolt hole diameter. This applies when the proposed gasket width corresponds to the standard width of semi-metallic gaskets, which is typically 1/2", 3/4...

  Understanding the Impact of Temperature and Pressure on Seal Performance An In-depth Look at How Different Temperature and Pressure Conditions Affect the Performance and Lifespan of Various Sealing Materials In the world of industrial fluid sealing, understanding how temperature and pressure impact seal performance is crucial. Seals are designed to prevent leakage, ensuring that fluids remain contained within a system. However, the conditions under which they operate can significantly influence their effectiveness and longevity. Let's delve into how different temperature and pressure conditions affect the performance and lifespan of commonly used sealing materials. Temperature: The Heat Factor Temperature extremes can greatly influence seal performance. Both high and low temperatures can cause material deformation, chemical breakdown, and loss of elasticity, leading to seal failure. Here's how different materials react: 1. Elastomers: High Temperatures: Elastomers lik...

    Introduction Many high temperature resistant fabrics exist and some are particularly well-suited for welding operations and what is more generally defined as ‘’hot works’’. Such welding fabrics have been thoroughly tested by the U.S. Navy (NAVAL SEA SYSTEMS COMMAND), since welding operations take place at sea. Potential fire would have dire consequences for equipment, personnel and mission operability. From these testings, specification MIL-C-24576A was established. Three products were specified : TABLE II Type I / Class I : Heavy silica cloth (36 oz) Type I / Class II : Light silica cloth (18 oz) Type III : E-glass silicone coated fabric : 30-36 oz/sq.yd. / 0.035'' to 0.043'' thick Comments For horizontal protection where molten metal will slowly cool down, Robco 188CH (MIL-C-24576A TABLE II - Type I / Class I) remains the material of choice. For vertical protection , a lighter silica fabric like Robco 84CH (TABLE II - Type I / Clas...

  In the process of gasket material selection, many inquiries point to the term “fire-safe”. Lets briefly look at the two most commonly used gasket fire testing methods: API 6FA & API 607. API 6FA: The American Petroleum Institute’s 6FA-re test is used to qualify valves for chemical process service.  The flange is assembled using proper bolt-up procedures and all parameters such as stress and torque are recorded. Thermocouples are mounted 1” away from the outside of the flange (Figure 1). The valve is enveloped in flame using four propane burners arranged symmetrically around the outside of the flange. The flame temperature should be 1400ºF to 1800ºF (average of the two thermocouples) for a burn period of 30 minutes from ignition. The temperature is maintained with no reading less than 1300ºF. An internal water pressure amounting to 75% of the flange rating is applied throughout the test and the leakage rate is continually measured. The test rig is then allowed t...

Flexible, removable insulation covers find application in heavy industries where swift or regular access to equipment is essential. These covers are crucial for insulating heat (or cold) to ensure safety, energy efficiency, and precision in industrial processes. A common inquiry revolves around the choice of fabric under specific circumstances. One pivotal factor to contemplate is whether the material is in direct contact with the equipment or exposed to external elements.   Presented below is a Decision Table to assist you in making informed choices:   Link We hope this table will facilitate your choice next time you require flexible removable cover insulation. Call Robco or Prodimax if you need further information.

  Transformers are an essential part of the electrical power distribution grid. Transformer gaskets’ materials are critical for their performance and longevity. Hence, this requires the best selection of sealing materials as leakage can lead to oil contamination of surrounding environment, damaging insulation materials and significantly reducing the life of a transformer. Proper gasket material will help maintain the transformer’s dielectric strength, prevent oxygen, nitrogen and/or moisture leaks, prevent oil contamination and more… Below are some options to consider for proper gasket material selection: Cork with Nitrile binder : traditional material used for decades. Easy to compress in place, fair weather and oil resistance. Low cost Nitrile rubber (NBR) : for general purposes with operating temperature between -30°C to 100°C. Low cost, easily available Fluoroelastomer ( V iton ® B, FKM) rubber : application for higher temperatures to 200°C. Expensi...

Quel est le coût d'une fuite de vapeur ? Pour ce scénario, nous avons deux tuyauteurs : Doodley DoRight et Didley Doofus . Les deux employés travaillent dans des entreprises similaires en ville, avec exactement le même niveau d'expérience et de formation. Doodley DoRight accorde une grande importance à l'installation des joints dans son usine, tandis que Didley Doofus est fier de la rapidité avec laquelle il peut installer le joint et passer à la tâche suivante.   Vous trouverez ci-dessous une comparaison côte à côte de l'installation par Doodley & Didley de chaque joint dans la même application pour un seul raccord de bride boulonné et des coûts associés sur une courte période de 12 jours. Sur la base de ce scénario, voici quelques éléments à prendre en compte : L'installation correcte des joints prend initialement plus de temps, mais elle améliore votre retour sur investissement (ROI) - en augmentant le bénéfice d'exploitation par la réduction des temps ...

What Will a Steam Leak Cost? For this scenario, we have two pipe fitters: Doodley DoRight & Didley Doofus . Both employees work at similar companies in town with the exact same amount of experience and training. Doodley DoRight places a high degree of importance on the installation of gaskets in his plant, whereas Didley Doofus prides himself on how fast he can install the gasket and move on to the next task .   Below is a side by side comparison of Doodley & Didley’s installation of each gasket in the same application in a single bolted flange connection and the associated costs over a short, 12-day period. Based on this scenario, here are a few things to consider: Proper gasket installation is initially more time consuming but it improves your return on investment (ROI) – increasing operating profit by reducing overall downtime and gasket inventory requirements. This analysis is based on one 3” 150# bolted flange joint. Just think about how many bolted joints are in an ...

  How to Simply Seal the Door of an Industrial Oven with a Tadpole Tape Gasket ? By: Jocelyn Vachon  VP Innovation Group - Robco There are a variety of types of industrial ovens with various door geometries. To seal the heat (radiation, convection, conduction) inside the oven, a flexible gasket is often required. Some ovens incorporate a groove to place an insulating rope. Also, strips or extrusions made of polymers from silicone or fluorocarbon can operate at relatively high temperatures. The most viable option, however, is a tadpole tape gasket. But, what is a tadpole tape gasket? What are the materials used ? A tadpole tape gasket consists of mineral-based textile materials (fiberglass, silica, ceramic) made into a seal starting with a core made of an insulating rope, surrounded by a sown fabric, the ends of which are allowed to extend (see graphic). A wire mesh can be added to the surface, to protect the fabric from excessive wear. Alternatively, a core of knitted metal wi...

  Comment sceller simplement la porte d’un four industriel avec un joint à bourrelet (tadpole) Par: Jocelyn Vachon VP Groupe Innovation - Robco Il existe une panoplie de types de fours industriels avec des géométries diverses au niveau des portes. Pour sceller la chaleur (radiation, convection, conduction) à l’intérieur du four, un joint flexible est souvent nécessaire. Certains fours intègrent une encavure pour y placer une corde isolante. Aussi, des bandes ou extrusions en polymères de type silicone ou fluorocarbure peuvent opérer à des températures relativement élevées. L’option la plus viable demeure cependant un joint à bourrelet. Mais, qu’est-ce qu’un joint à bourrelet ?   Quels sont les matériaux utilisés ?  Souvent connu sous son nom anglophone de tadpole tape , le joint à bourrelet consiste à fabriquer à partir de textiles à base minérale (fibres de verre, silice, céramique) un joint, débutant avec une âme faite d’une corde isolante , sur lequel on entoure et ...

Est-ce possible qu’une fuite soit causée par une bride endommagée ? Défaillance d’une bride. D ans un système de tuyauterie, les brides sont un élément essentiel pour un confinement idéal. L ’intégrité structurelle d e la jonction ne doit jamais être affectée, cependant la défaillance due à la bride est un problème a ssez peu courant, mais peut être catastrophique. pour le confinement, C ette défaillance lié a la bride est principalement due à : • S urfaces de bride s endommagées: ou revêtement de bride incorrect, car les dentelures plus profondes que celles spécifiées empêcheront l'assise, en particulier dans les joints métalliques et semi-métalliques comme les joints enroulés en spirale s (veuillez vous reporter à notre publication précédent e : Finition de surface de bride vs type de joint ). • B rides tordues: Des mouvements de flexion excessifs sur la bride peuvent desserrer le boulonnage ou déformer les brides et entraîner des fuites. Cette situation peut également ê...

  Is it possible I have leakage because of a damaged flange? Flange failure: In a piping system, flanges are an essential element for ideal containment. The structural integrity of the junction should never be affected, however flange failure is a fairly uncommon problem but can be catastrophic. Flange failures are primarily due to: • Damaged flange surfaces or Improper Flange Facing, because the deeper serrations than specified will prevent the seating especially in metallic and semi metallic gaskets like spiral wound gaskets (please refer to previous blog entry entitled: Flange Surface Finish vs Gasket type ). • B uckling flanges: Excessive bending movements on flange s can loosen the bolting or distort the flanges and lead to leaks. This situation can also be produced by thermal s hock where the rapid temperature fluctuations can cause flanges to deform temporarily. • Non-parallel flanges: Improper flange face parallelism, causes uneven gasket compression, local ga...

As a rule of thumb,70% of shaft wear from braided packing is caused by the first and second rings adjacent to the gland follower. Why? Imagine you had 4 identical full cardboard boxes in a row and pushed on the first one, all 4 boxes would move as one. Packing does not react that way, as compressible braided packing needs to densify sufficiently to push on the next ring and so on. It is the bottom ring in the stuffing box that needs to be compressed in order to produce an efficient seal. But how can you get the load from the gland follower to this ring? The answer is to use die-formed, or pre-compressed packing rings, allowing the compressive load from the gland follower to move all of the rings equally. The obvious advantage is activating all the rings in the set, including the all important ring that sees the media to be sealed, while reducing overall friction on the shaft/sleeve. Good quality die-formed rings are usually provided as individual sets for each stuffing box, already ...

En règle générale, 70 % de l'usure de l'arbre due à la garniture tressée est causée par les premier et deuxième anneaux adjacents au fouloir de presse-étoupe. Pourquoi ? Imaginez que vous aviez 4 boîtes en carton pleines identiques à la suite l’une de l’autre et que vous poussiez sur la première, les 4 boîtes se déplaceraient comme une seule. La garniture ne réagit pas de cette façon, car la garniture tressée compressible doit se densifier suffisamment pour pousser sur l'anneau suivant et ainsi de suite. C'est la bague inférieure de la boîte à garniture qui doit être comprimée afin de produire une étanchéité efficace. Mais comment pouvez-vous faire passer la charge du presse-étoupe à cet anneau ? La réponse est d'utiliser des bagues de garniture moulées ou pré-comprimées, permettant à la charge de compression du fouloir de presse-étoupe de déplacer toutes les bagues de manière égale. L'avantage évident est d'activer tous les anneaux de l'ensemble, y c...

  Wiper blocks, also referred to as wiping pads are used in the steel wire “continuous hot-dip” galvanization process. Steel wires are immersed in molten zinc to render them corrosion resistant. Small amounts of aluminium are also sometimes added. Galvanized wires are being used in a wide range of industries and manufacturing applications.  The continuous hot-dip process requires to wipe excess molten zinc and leave a smooth, bright coating onto ASTM Class I or III wires. As they exit the galvanizer, each wire passes longitudinally between a set of rectangular pads called wiper blocks. A screw mechanism compresses each set of wiper blocks together to tightly wipe the wire before it enters the quench tubes designed to cool off the wire. Wiper blocks are available in a variety of sizes to suit various wiping systems and wire diameters. They are manufactured from high temperature resistant materials known for their abrasion resistance and moulded into rectangular pads, rolled in...