Valve Magazine - Spring 2010

The Wedge Plug Valve

The double block-and-bleed feature of the wedge plug valve provides a solid foundation for product safety under severe conditions. The wedge plug valve is often referred to as an “isolation valve” because its design allows the medium to be secluded, which is a critical requirement in many applications.

Wedge plug valves also offer superior protection from erosion damage, from solids build-up on sealing surfaces and in cavities, and from residual freeze-up, which can prevent operation and cause leakage from wear. The wedge plug valve is double-seated, which provides two isolation seals in contrast to the single seat afforded by a metal-seated ball valve.

SMART VALVE ACTUATORS As with most issues in the valve industry, there is more to valve safety than the valve itself. For power-operated valves, a smart digital valve actuator can perform diagnostics and maintain an internal database of valve characteristics as they change over time. This can alert operators to such problems as increased friction and, in the case of control valves, changes in calibration.

In addition, a smart valve actuator on an emergency shutdown valve can be used to perform full stroke testing during scheduled plant shut-downs and partial stroke tests at regular intervals while the plant is running; in fact, it can help to elevate the safety integrity level (SIL) of a valve used in a Safety Instrumented System (SIS).

SUMMARY

No business that deals with chemical processes can afford to take chances when it comes to employee and environmental safety—the consequences of leaks and fugitive emissions can be hazardous and potentially lethal. For this reason, the best way to ensure safety is to select and install the right equipment components as well as the appropriate valves. VM

WILLIAM C. HAYES is vice president of marketing (Global) for Crane ChemPharma Flow Solutions.

Your Pipeline to
Flange Protection

Caplugs offers a full line of flange covers and pipe caps in a wide variety of sizes, styles and materials. These inexpensive covers protect the face of the flange, maintaining the integrity of the sealing surface, while keeping the interior free of contaminants.

Caplugs parts can be used anywhere valves, piping, pumps and other processing components with connections need to be protected. For unique product protection needs, we have full in-house custom capabilities.