Media containment: Still a major concern
Any leakage from a valve in service is a major concern. It is even more critical when the process being controlled involves hazardous materials.
Ball valves typically leak from the stem following prolonged usage. Maintenance engineers normally stop a stem seal leak by tightening the packing nut 1/6th of a turn (usually one flat of a nut). This places additional force on the packing, allowing further expansion against the stem and containing the leak.
However, at some point no additional tightening will seal the leak.
Once this happens the valve has to be repaired or replaced, often requiring a shut-down.
Flo-Tite, with its media containment device, has a cost-effective and environmentally safe solution. The media containment unit is basically a duplicate valve-stem seal system, which can be added to the valve when purchased or kept in stock for when a stem leak is detected.
Device installation for a valve in service is simple. For a manual valve the handle is removed, the device is installed on the valve top and the handle replaced. With an automated valve, the automation package is removed and replaced on top of the device bonnet.
A drilled or tapped purge port on the side of the device is a standard option, used for monitoring gauges, measuring instruments or as simple “sniffer device.” Plants can avoid emergency shutdowns, eliminate leaking valve replacement and take prudent steps to reduce employee risk and facility damage. This safe solution to a known problem means maintenance can be scheduled and a managed course of action pursued, without facing emergency situations that might include plant shut downs or personnel evacuation.
The media containment unit can also act as a positive purge, using some material or, for example, nitrogen to attain a pressure that exceeds the internal line pressure, and inhibiting valve leakage due to the positive purge. Also, by adding a “button-type” check fitting, emergency sealing materials can be injected for additional sealing.
The media containment unit is a cost-effective and much-needed solution for potentially dangerous environmental and plant personnel safety situations. As environmental regulations are put in place for hazardous media leakage, Flo-Tite’s media containment device offers a simple and safe solution.