As is well known, ball-valve stem leakage is a costly and time-consuming problem. Most ball valves can develop stem leakage. When it happens, it might mean shutting down and replacing the valve.
Moreover, depending upon the media involved, leakage could lead to a hazardous situation. The sheer number of valves installed in process control around the world makes stem leakage a significant environmental concern.
Lumberton, N.C.-based Flo-Tite Valves & Controls says its media-containment unit is a cost-effective solution easily adapted to both manual and automated valves. Moreover, it incorporates a triple set of stem seals.
For severe-service requirements, the same device — with graphite-stem packing and live-loaded Belleville washers — automatically compensates for temperature and pressure fluctuations, maintaining a leak-proof seal and extending valve cycle life. It can also help distance the valve operator from dangerous high-temperature media — a significant safety feature.
For lubrication and sealing, a button-head check valve used for sealant injection acts as a third seal or optional emergency shut-off.
A “sniffer” pressure gauge or sensing device option detects a primary stem seal leak early.
An airline can be connected to the media containment cap for a positive pressure that exceeds that of the valve line and prevents valve-stem leakage to atmosphere.