Profile: Online Sealing Services Ltd. specializes in on-line leak sealing services. We offer consultation services for leak sealing, bolting, safety relief valve testing & repair, on-site machining, pipeline intervention (hot tapping, line stops and line freezing), emission data, turn around services & product development. On-line and under pressure leak sealing is the process of stopping the undesirable & potentially hazardous escape of liquid or gas from plant equipment, while the plant remains on-line & operating.