Robco Expert

    Introduction Il existe de nombreux tissus résistant aux hautes températures et certains sont particulièrement adaptés aux opérations de soudage et à ce qui est plus généralement défini comme le « travail à chaud ». De tels tissus ont été minutieusement testés par la U.S. Navy (NAVAL SEA SYSTEMS COMMAND), puisque des opérations de soudage ont lieu en mer. Un incendie potentiel aurait des conséquences désastreuses sur l'équipement, le personnel et leur mission. À partir de ces tests, la spécification MIL-C-24576A a été établie. Trois produits ont été spécifiés : TABLEAU II Type I / Classe I : Tissu de silice épais (36 oz) Type I / Classe II : Tissu de silice léger (18 oz) Type III : tissu de verre grade-E enduit de silicone : 30-36 oz/vg². / 0,035'' à 0,043'' d'épaisseur Commentaires Pour la protection horizontale où le métal en fusion refroidira lentement, Robco 188CH (répondant au MIL-C-24576A TABLE II - Type I / Classe I) reste ...

    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...