• Forbes Marshall Private Limited

Remote Seal Filling for Transmitters

Forbes Marshall has been supplying gauges with diaphragm seals for high temperature/high viscosity/hygienic applications. The company has a semi-automatic filling station as per international standard ASME, Section VI/ASTM B 40.3. The process involves heating of the fill fluid up to 100°C to expel all moisture content and hydrocarbons in oil. This ensures that the fill fluid is devoid of gaseous elements including moisture, which can cause erratic functioning of seal such as inaccuracy due to changes in room temperature. The temperature is monitored with RTD sensor and magnetic stirrer employed to have homogeneous fluid and easy removal of gaseous components. The gases are removed through a hydrocarbon trap/active carbon filter and are collected in collector mounted on vacuum pump. The same vacuum pump is used to evacuate the chemical seal and capillary (if applicable) up to 10 microns, measured by Pirani gauge. The hot fluid is then let into the seal space, for uniform and effective filling. The filling port is capped/closed under positive head of fluid avoiding any intrusion of air bubbles and enabling perfect seal. This filling station is enabling the company to increase the production of sealed units four fold. After getting vast experience in seal filling, it is extending the same for pressure transmitter and DP transmitters irrespective of make. Also it undertakes repair of remote seals. Presently the company is offering 5 mtr long capillary seals with standard flange connections of 1”, 1 ½ ”, 2” of ANSI/DIN/BS standards. The fill fluid will be DC 200 for temperature up to 250°C and DC 704 for temperature up to 400°C.