
Valve packing is vital to prevent leaks during valve operation. However, standard packing materials may not always be right for severe service applications. Industrial valve modification like a valve packing change out for new valves can help make sure the valves perform as required in demanding conditions.
For professional valve packing replacement, contact Southern Valve Service – your expert in industrial valve repairs and modifications.
Understanding Valve Packing
Valve packing sits within a space called the stuffing box. Packing creates a seal by being compressed within the stuffing box, filling the space and putting constant pressure on the valve stem to prevent leaks.
Common packing materials used in industrial valves include:
- Graphite: High-temperature resistance and excellent sealing properties.
- PTFE (Teflon): Superior chemical compatibility and low friction.
- Synthetic Fibers: Good for general-purpose sealing in various fluid applications.
The appropriate material for your industrial valve depends on the valve’s function, the type of liquid or gas it handles, the operating pressure, and the temperature requirements.
Packing Upgrades for Extreme Temperatures
Teflon packing, while widely used, has temperature limitations that can lead to premature failure in high-heat scenarios. Grafoil packing is a superior replacement, with a significantly expanded operating temperature range. While grafoil packing may have a higher upfront cost compared to Teflon, its superior durability and reduced downtime often result in long-term savings.
Grafoil is a pure, flexible graphite material. It withstands extreme temperatures far exceeding Teflon’s capabilities (up to 1200°F in steam service and even higher in other environments). This translates to greater reliability and reduced maintenance needs in high-temperature systems.
Grafoil can also maintain its integrity even when exposed to a broad range of aggressive chemicals. Its inert nature makes it ideal for demanding chemical processing and other harsh environments where Teflon may degrade. In addition, it has a low coefficient of friction, minimizing wear on the valve stem and helping to extend overall valve life.
Live Loading for Maintaining Consistent Packing Tension
Valve packing naturally relaxes over time and is further affected by thermal expansion and contraction. These fluctuations in packing tension can lead to leaks and fugitive emissions. Live loading with Belleville washers provides a solution. With live loading, there’s less need for frequent manual tightening of gland nuts. This saves valuable time and labor while minimizing the risk of overtightening.
Belleville washers are conical-shaped spring washers exert a high force over a relatively short deflection. They apply continuous, controlled pressure on the packing, so even when temperature changes cause the valve body and stem to expand or contract, the Belleville washers dynamically adjust. This adaptability maintains consistent packing tension, preventing gaps and leaks. These washers are also available in various materials to match the valve’s operating environment and temperature range.
Low Emissions Packing Options for New Valves
Environmental regulations surrounding fugitive emissions (unintentional leaks of gases or vapors) are becoming increasingly stringent. To comply and minimize environmental impact, new valves can incorporate low emissions packing.
Low emissions packing are specialized materials that demonstrate extremely low leakage rates, often below 100 parts per million (ppm). They frequently incorporate PTFE variants, flexible graphite, or a combination of both.
Industrial valve modifications that use this type of packing help you meet emissions standards and avoid costly fines, and demonstrates your company’s commitment to environmental responsibility. While low emissions packing might have a higher initial cost, reduced leaks and compliance penalties can offer greater savings over time.
Expert Technicians for Critical Industrial Valve Modifications
Valve packing change outs are essential for maintaining leak-free, efficient industrial valves. Trust Southern Valve Service for thorough assessments, the right materials, and precision workmanship – all within our dedicated valve repair shop. Contact us today to discuss your industrial valve maintenance, repair, or modification needs.