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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...

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 ...

  What is standard API 622? By J.Melançon - Robco Inc. API 622 is a standard developed by the American Petroleum Institute (API) that specifies the requirements for the design, testing, and performance of packing systems used in rising stem valves for fugitive emissions control. Specifically, API 622 provides guidance on the design and testing of valve packing systems to reduce fugitive emissions from valves used in volatile organic compound (VOC) and hazardous air pollutant (HAP) service. The standard specifies the minimum performance requirements for the valve packing, such as maximum allowable leakage rates, as well as the test procedures to be used for evaluating the performance of the packing system. API 622 is intended to provide a consistent and reliable approach for controlling fugitive emissions from valves, which is an important aspect of environmental and safety management in the oil and gas industry. Testing API 622 specifies several test procedures to evaluate ...

  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 ...

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...

  Les blocs d'essuyage, également appelés tampons d'essuyage, sont utilisés dans le processus de galvanisation à chaud en continu du fil d'acier. Les fils d'acier sont immergés dans du zinc fondu pour les rendre résistants à la corrosion (De petites quantités d'aluminium sont aussi parfois ajoutées). Ces fils galvanisés sont utilisés dans un large éventail d'industries et d'applications de fabrication. Le processus continu d'immersion à chaud nécessite d'essuyer l'excès de zinc fondu et de laisser un revêtement lisse et brillant sur les fils ASTM de classe I ou III. A leur sortie du galvaniseur, chaque fil passe longitudinalement entre un ensemble de tampons rectangulaires appelés blocs d’essuyage. Un mécanisme à vis comprime chaque ensemble de blocs d’essuyage pour essuyer étroitement le fil avant qu'il n'entre dans les tubes de trempe conçus pour refroidir le fil. Les blocs d'essuyage sont disponibles dans une variété de tailles...

System Flushing is a bit of tricky business. In oil circulating systems, dirt, varnish, lacquer and sludge cleaned from the systems will become partially soluble in a flushing lubricant and can be carried to filters and oil pump intake screens. These should be closely monitored to assure continued oil flow. Deposits are also likely to settle to the lowest point of the oil reservoir. Large capacity, bypass or inline filtration is recommended during cleanup for many dirty systems since the standard filters lack capacity and can quickly plug. The Big Question is: When do we need to flush and when do we not need to flush an oil system? This is the question that many maintenance managers, planners and lubricant specialists have trouble deciding upon. Here are the main reasons to do an oil system flush: Does the oil analysis show signs of contamination due to water? Does the oil analysis show signs of metal wear in it? Has the Total Acid Number (TAN) incre...

What are Spray Safety Shields? Spray safety shields, are installed on pipe joints, these being the ‘weak points’ where leaks typically occur. For critical pressurised applications, they are the vital first line of defence to prevent fire, explosion and toxic release which would otherwise endanger plant and personnel. Prevent Spray-outs - Generally the most important requirement is to control the leak, create a safe release and thus avoid a dangerous spray-out, which would otherwise happen even at low pressure. Avoid oil mist formation - For certain oil & fuel applications, oil mist formation is just as hazardous as a spray-out. Furthermore, ill-fitting safety shields can actually create mist formation. Provide leak indication - It is important to identify leaks as quickly as possible, though the process will determine the urgency. For certain acid lines, some customers require that flanges must not be concealed. This is achieved using transparent shielding. Alternatively leak-indic...

Qu'est-ce qu’un écran de sécurité de pulvérisation? Des boucliers de sécurité contre les pulvérisations sont installés sur les joints de tuyaux, ceux-ci étant les « points faibles » où les fuites se produisent généralement. Pour les applications pressurisées critiques, ils constituent la première ligne de défense vitale pour prévenir les incendies, les explosions et les rejets toxiques qui, autrement, mettraient en danger l'usine et le personnel. Empêcher les éclaboussures - Généralement, l'exigence la plus importante est de contrôler la fuite, de créer une libération sûre et d'éviter ainsi une éclaboussure dangereuse, qui se produirait autrement même à basse pression. Éviter la formation de brouillard d'huile - Pour certaines applications d'huile et de carburant, la formation de brouillard d'huile est tout aussi dangereuse qu'une pulvérisation. De plus, des écrans de sécurité mal ajustés peuvent en fait créer une formation de buée. Fournir une indicat...

  Compression versus Load: what should you use? Lotfi Grine, Eng. – Product Specialist at Robco One common question concerning sealing tightness with flat gasket materials is the proper compression percentage or/ and the amount of force needed to compress them. This is a critical design parameter. These two parameters can affect the number, type, size and spacing of attachments like bolts to prevent housing deflection, flange rotation and subsequent leakage. Because several gasket materials consist in a composite, like semi-metallic or compressed sheet gasket materials, it is the level of torque (load), rather than the level of gasket compression expressed in percentage that matters. T his level of torque will be chosen according to different parameters like bolts grade, flange type, maximum and minimum sealing stress, etc.  For Klinger compress sheets and gaskets, Robco uses KLINGERexpert software to assist users for improved scientific calculations of bolt torque requi...

TENIR COMPTE DE L'EXPANSION ET CONTRACTION THERMIQUE LORS DE L'USINAGE DU NYLON Thomas Cipriani – Product Specialist at Robco Lorsque l'on travaille avec du nylon, nous devons comprendre qu'il réagit aux fluctuations de température. La meilleure procédure à suivre lors de l’usinage du nylon en usine est de le découper à une température d’environ 24°C; si nous ne le faisons pas, nous risquons d'avoir des problèmes dimensionnels après coup. Le nylon étant un plastique thermique, il se dilate lorsqu'il est soumis à des températures plus élevées et se contracte à des températures plus basses.  Toujours prendre la température d'installation en considération.  Voici une formule de travail pour vous aider lorsque vous souhaitez usiner des pièces à base de nylon: Voici quelques exemples: > A) Exemple d'expansion: En installant à 78°F, la température maximale de fonctionnement peut atteindre 150°F et la pièce mesure 120" de long 150° - 78° = 72° de change...

TAKING INTO ACCOUNT THE THERMAL EXPANSION & CONTRACTION WHEN MACHINING NYLON Thomas Cipriani – Product Specialist at Robco When working with Nylon material, we must understand that it reacts to temperature fluctuation. The best procedure to follow when machining Nylon at the factory is to cut it to size at a temperature of about 75°F; if we don't, then we risk having dimensional issues later on. Nylon is a thermal plastic, hence it will expand when subjected to high temperatures and contract at low temperatures. Always take into account the installation temperature. Here is a working formula to help you when machining Nylon based parts: Here are some examples: >A) Expansion Example: Installing at 78°F the maximum operating temperature can reach 150°F and the piece is 120” long: 150° - 78° = 72° temperature change 72 x 120 x .00005 = .432” expansion >B) Contraction Example: Installing at 78°F the lowest operating temperature could reach -200°F and the piece is 120” long: 7...

What gasket material to use on sheet metal flanges for ventilation systems Jocelyn Vachon - VP B.Dev / Product Specialist Gasket materials require to be compressed, in order to achieve a seal. What materials should you use when flanges are simply made of thin sheet metal? Ventilation systems assembled on-site require gaskets between sections. Sheet metal flanges cannot create a high, evenly dispersed mechanical load on gasket materials, even if internal pressures are low (6 to 12 inch of water on average).   Here are a few suggestions: Closed cell sponges with a durometer of 20 to 60 (shore 00 scale) are good options Neoprene-based sponges (Robco SC-41 soft / SC-42 medium / SC-43 firm) are the most popular. Self-adhesive strips can be formed (round flanges) or cut in lengths (square flanges) for a quick and wasteless assembly PTFE saturated woven glass tapes (Robco GW-305) can be used where temperatures are above 250°F (130°C) and where a ...

Choosing the right type of stainless-steel grade to use for spiral wound gaskets is important. Lotfi Grine, Eng. – Product Specialist at Robco The media concentration, temperature and time requirements provide a variety of work conditions for spiral wound gaskets.   The metal components are subject to different types of attack, including pitting, cracking, stress corrosion cracking and intergranular corrosion. It’s important to specify, that the standard stainless-steel used for Robco SWG is normally Type 316L . Other high quality alloys are available (ex : hastelloy, inconel, monel, etc.) for higher temperature or other special applications Here are the particularities of stainless-steel grades used generally in the manufacturing of spiral wound gaskets: Stainless steel type 304 serves a wide range of applications. It resists organic / inorganic chemicals. The main limitation of Type 304 is stress corrosion cracking and intergranular corrosion when the temperature exceeds 800°...