_Sistemas de Presurización___Otros productos__Sistemas a la medida especificaciones del sistema de purga Z

‘Z’ Purge Specifications

  Suggested Specifications for Type ‘Z’  Purge Control Systems  


The Manufacturer shall provide a Purge Control System that will be used to purge and pressurize an enclosure containing non-classified electrical components when used in a Class I, Division 2 Hazardous Location. The purpose is to allow regular electrical equipment to be operated safely in a hazardous area or location. The pressurization media (provided by others) shall be in the form of air, nitrogen, or other inert gases. The Purge Control System shall meet or exceed the NFPA 496 Standard for Purged and Pressurized Enclosures for Electrical Equipment. The Purge Control System shall be entity approved by Factory Mutual (FM) and Underwriters Laboratory (UL and cUL) for use in Class I, Division 2 environments.


Components of System

The ‘Z’ Purge Control System shall consist of a Control Unit (CU), Relief Valve (RLV),  and/or Spark Arrestor Unit (SAU). The CU controls the supply, measurement, and flow of the protective medium, and provides the outputs to indicate status.  The CU shall be designed to operate in either a Leakage Compensation (LC) or Continuous Flow (CF) mode of operation. The RLV (in LC mode) or the SAU (in CF mode) shall provide a means to measure the purge medium at a defined outlet to ensure effective purging through the enclosure during the initial purge cycle. The SAU (provided with Continuous Flow {CF} Systems only), is designed to provide continuous air flow through the protected enclosure, and measure purge flow by means of orifice plates.

  Suggested Specifications for Type ‘Z’  Purge Control Systems  

System Requirements

The ‘Z’ Purge & Pressurization Control System shall be designed to meet the following criteria:

-       Independent of Supply Voltage.
-       For direct mounting or panel mount to the protected enclosure in order to eliminate unnecessary piping connections, and to permit ease and simplicity of installations.
-       316 Stainless steel, corrosion resistant mounting hardware for use in harsh and extreme environments.
-       The use of bi-colored Roto Indicators for “Local Alarm” and “Purge in Progress” conditions, and readable at up to 180 degrees.
-       Contain an  intrinsically safe / non-incendive Remote Alarm Switch with SPDT contacts.
-       Magnetically operated and Factory Calibrated Relief Valve.
-       Purge Flow shall be measured by the 316SS Relief Valve (LC Systems) or the Spark Arrestor Unit (SAU) outlet (CF Systems) in order to provide Full Compliance with Purge and Pressurization Standards.
-       Manufacturer shall be ISO 9000 Certified.


The ‘Z’ Purge & Pressurization Control System and all of its components shall be manufactured by:

Expo Technologies, Inc.
P.O. Box 486
Chagrin Falls, Ohio 44022
Phone 440-247-5314
Fax 440-247-5409
E-mail: sales.na@expoworldwide.com

A otros sistemas, purga Z