Pepperl+Fuchs' New 5500 Type Z/ Ex Pz Smart Purge System
When machine and process skid builders have customers that place their machines in hazardous locations, the builders often must incorporate panel purging/pressurization systems to ensure safe operations. This usually isn't a core competency, so the OEMs need to rely on third-party expertise.
Pepperl+Fuchs wants to provide that level of expertise to these builders, and its new 5500 Type Z/Ex pz purge system is designed to help OEMs, panel builders and just about anyone dealing with haz-loc areas by making this type of system easy to implement.
"The 5500 Purge+Pressurization system is application-oriented, letting users select from a menu of pre-configured programs," says Chris Romano, Pepperl+Fuchs' product portfolio manager/purge and pressurization. "Options such as bypass, temperature monitoring, alarm and control, leakage compensation control and continuous pressure indication, along with LED indicators of the status of the system, makes this system easy to implement, install and operate. Reliability over the full temperature range of -20 to 60 °C will prevent false trips of the system."
Romano says that when Pepperl+Fuchs set out to develop the 5500 series, the benchmark was to improve those capabilities that have a great impact on the user's process and performance. "First, the unit was developed with an interface that allows users to select a custom program for their applications, and it works in conjunction with the enclosure protection vents [EPVs] and pneumatic solenoid valves or manual valves that comprise the system," he explains. "RTDs [resistance temperature detectors] can be connected to inputs, and the user can select temperature ranges for controlling and alarming critical temperatures through a set of contacts and energizing a solenoid valve for displacing air within the enclosure."
Another feature is the system's ability to automatically control pressure when a drop in pressure is detected. "There is a pressure setting for the solenoid valve to energize when a user-selected low-pressure value is reached, so pressure will not go below minimum value," Romano explains. "This rapid exchange process and leakage compensation aids in preventing an alarmed shutdown, which saves a company valuable time and money."
Romano points to the smart features of the EPV-5500 vent. "First, the EPV-5500 vent works with the 5500 control unit and valve to provide a functional, certified, purge and pressurized system for enclosures," he says. "As required by all pressurized enclosure systems, the EPV-5500 vent functions as a pressure-relief device and allows the purge gas to exit the enclosure, but provides a seal when the enclosure is pressurized and operating. One of the vent's features is a pressure-relief mechanism that provides a very well-sealed opening when the enclosure is below a certain pressure. This vent type is great when using expensive nitrogen sources or bottled gas sources for pressurization. It can save on the cost and maintenance of replacing bottle sources. The unit also has a spark arrestor, which is required for hazardous areas."
The control unit is 316 stainless steel with optional types of cable glands and conduit fittings, and the vent body is 6061T6 anodized aluminum with a 316 stainless steel cap. The vent can be mounted inside the enclosure with the cap external. The opening mechanism for the vent opening is spring-loaded, so that any orientation allows for proper operation of the vent.
The 5500 has two mounting options. It can be mounted within the enclosure so that only the display is showing through the enclosure, or it can be mounted outside the enclosure and can be mounted left, right, top or bottom of the enclosure because the display can be rotated for those positions.
The system has cULus, ATEX and IECEx certification for Class I & II, Division 2, Zone 2 & 22.