Saint-Gobain Seals has developed a new single stem sealing solution, which is targeted to lower fugitive emissions within ON/OFF valves in the oil and gas industry and create a more environmentally-friendly option for manufacturers who are dealing with increasingly stringent regulatory and legislative requirements that impact environmental health and safety. In studies conducted on oil and gas processing facilities, valves have been shown to be a major source of fugitive emissions; therefore, this piece of equipment poses the greatest opportunity for reducing fugitive emissions. By effectively containing these types of emissions, manufacturers not only benefit environmentally but also promote operating efficiency and safer, productive workplaces.
In order to meet future challenges for fugitive emissions, Saint-Gobain Seals began the process quite some time ago with the development of their low fugitive emission (LFE) seals. The objective was to develop a single stem sealing solution for ON/OFF valves that passed leakage tightness of Class BH and endurance class CO1 (500 cycles) from -50 °C to 160 °C according to the ISO 15848 quality standard. Since each valve can have up to four or more possible emissions centers: a bonnet gasket, two flange gaskets and a valve stem (which is the main emission source for valves), their main focus became concentrated on engineering a solution with the valve stem.
In order to achieve this, Saint-Gobain Seals invested in a test rig that solely operated according to the ISO 15848-1 criteria. Their first step was to study the impact of jacket and spring designs on LFE leakage performance. They also selected materials that optimized leakage performance by limitation of permeation. The next step was to optimize the design of their V-packing component to improve leakage performance with the help of FEA analysis. Based on testing data and past experience and knowledge, they developed different design concepts using their well-established and proven OmniSeal spring-energized product to pass the specification. To validate the new OmniSeal designs, Saint-Gobain Seals Research & Development used helium as test fluid while the measurement was conducted in a close chamber under vacuum with a mass spectrometer for detection to give the highest accuracy.
Compared to other sealing solutions for low fugitive emissions such as compression packings, the OmniSeal spring-energised seal offers the following benefits:
- Compliant with ISO 15848-1 Class B, from -50°C to +160°C, endurance class CO1 (500 cycles).
- No need for secondary seal.
- High Pressure, High Temperature combinations.
- Easier installation compared to compression packings.
- Does not need to be compressed axially.
- Lower operating torques/forces.
- Long life.
Adapted from a press release by David Bizley
Read the article online at: https://www.hydrocarbonengineering.com/product-news/14112014/saint-gobain-develops-omniseal-single-stem-sealing-solution-for-quarter-turn-valves/