990-04-50-02-00 The long-life, high-performance valve uses a heavy-duty polymer seat with a support ring, internal wound gasket and designed clearance so that the seat can be elastomically compensated as the flange surface of the valve plate is reseated. This design provides a bubble-grade seal while extending service life.
To achieve these benefits, advanced seat design and plate upgrades are required to reduce contact. The seat is made of PTFE or RTFE and is supported by a support ring and reinforced by wire winding inside the seat. This design provides a bubble-grade seal with very little wear.
The adjustable seat is fitted with the valve plate to achieve bubble-level sealing und990-04-50-02-00 er full vacuum to rated pressure conditions. It also maintains a low leakage rate when pressurized on both sides of the valve, and performs equally well regardless of the type of pipe installation and process media flow.
Another innovative design point involves the upgrade of the valve plate and stem so that the valve plate is completely removed from the seat at stroke up to 7 degrees, with minimal plate/seat contact reducing valve wear and further increasing the seat life.
Stem seal design
The environmental laws of various countries in the world have more and more stringent requirements for runaway emissions, so the leakage rate of valve packing is required to be reduced to a minimum. Valve packing designs must meet conflicting requirements – leakage rates must be kept close to zero even if the packing wears out, which often requires a high squeeze seal on the packing, and the packing must provide a low friction surface that reduces friction generated during stem rotation over the life of the valve.
Keeping up with The Times, environmentally friendly packing solves this problem by co990-04-50-02-00 mbining special materials and advanced packing design (Figure 2). Dynamic loading packing gaskets maintain constant pressure on the packing ring, which consists of braided and V-shaped rings made of many different materials to meet the pressure and temperature requirements of the application. To extend packing life and reduce friction, the stem must be made of a high-hardness material.
