Robco Expert

 Dans le processus de sélection des matériaux de joints, de nombreuses questions portent sur le terme "sécurité incendie". Examinons brièvement les deux méthodes d'essai au feu les plus couramment utilisées pour les joints : API 6FA ET API 607. API 6FA : Le test 6FA-re de l'American Petroleum Institute est utilisé pour qualifier les vannes destinées aux procédés chimiques. La bride est assemblée selon les procédures de boulonnage appropriées et tous les paramètres tels que la contrainte et le couple sont enregistrés. Des thermocouples sont montés à 1 pouce de l'extérieur de la bride (figure 1). La vanne est enveloppée d'une flamme à l'aide de quatre brûleurs au propane disposés symétriquement autour de l'extérieur de la bride. La température de la flamme doit être comprise entre 1400ºF et 1800ºF (moyenne des deux thermocouples) pendant une période de combustion de 30 minutes à partir de l'allumage. La température est maintenue et aucune valeur n...

  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...

  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...

  Pressure capability guidelines: There are many gaskets materials type, and the pressure ability to withstand for each materials type is different. It starts from low pressure for soft gasket material up to high pressure for metallic and semi-metallic gaskets. So, according to the pressure level high or low we need choose the right gasket material to create a reliable seal. The chart below provides a guide to the suitability of our materials in standard ANSI flanges. Note: It should be noted that the ability to withstand assembly load is also dependent on the temperature of the application, and therefore gasket selection must be cheked with the pressure/temperature graphs given for each material. We use Klinger reference of material styles because those are the ones we know best. Materials Class 150 (20 bar) Class 300 (50 bar) Class 600 (100 bar) Class 900 (155 bar) Class 1500 (260 bar) Class 2500 (4...