CMRI certificate for Ex p panel for use in gas group IIA and IIB, zone 1 and zone 2 hazardous areas  as per IS/IEC 60079-2:2007 has been ** RECEIVED **.

Benefit of using panel / system with pressurization

Panel / system with suitable type of pressurization allows one to use general purpose equipment and/or stdandard enclosures in hazardous locations.

Panel / system with suitable type of pressurization are smart alternative to using expensive explosion proof enclosures and/or equipment with intrinsic safety barriers in hazardous locations.

Hulasi offers panels with Y and Z types of pressurization

Components of purge panel:

1. Standardized or Customized IP55 Enclosure [internal volume less than 75 Cubic feet]
   e.g. cabinet of size 2200 x 800 x 800
   

2. Purging system:

   i) Air Filter Regulator: Provides regulated protective gas to the protectie enclosure, shows pressure of regulated protective gas, Filter's regulated protevtive gas suuply.

   ii) Purging Valve: Ball valve for supplying high flow rate of protective gas supply for purging.

          iii) Pressurization valve: Needle valve for supplying a continuous protective gas supply for pressurization.

         iv) Differential Pressure gauge

        v) Start-up Labels: This provides the correct procedure for purging and pressurizing the protective enclosure.

        vi) Warning Labels: Stainless steel label must be placed onto the protective enclosure and indicates this is a pressurized enclosure.

       vii) Differential Pressure Switch: Provides a contact output when a pressure inside the protective enclosure drops below 0.2" water pressure. The contact outpur is used to drive an alarm for pressure loss inside the protective enclosure.

       viii) Enclosure Protection Vent: Used as a relief vent during and after purging.

Black diagram of purge control system

Hulasi offers standardized IP55 rated enclosures with Y and Z type purging.

Depending up on the quantity Hulasi can customize the IP55 enclosures as per customers' special requirements.

Please fill our Request for Quotation [RFQ] form so that we can send offer for appropriate purge panel system.

Purge panel system background information

Reference standard

The American National Fire Protection Association's (NFPA) standard 496 is used as the base for purge panel system design by Hulasi.

Link to "NFPA 496 - Purged and Pressurized Enclosures for Electrical Equipment."

Types of Purge / Pressurized systems

The NFPA 496 defines "Types" of pressurization based on the Division rating of a hazardous location and electrical ratings of the protected equipment. General-purpose and Division 2 rated electrical equipment require different means of protection, depending on their location.

Panel / System with Type "X" Pressurization is used to protects general-purpose equipment in Division 1 or zone 1 Areas. This system reduces the classification within protected enclosures from Division 1 or zone 1 to (unclassified) non-hazardous. A cutoff switch is required to de-enrgize power automatically to all protected equipment within the protected enclosure in case of failure of the pressurization system.

Panel / System with Type "Y" Pressurization is used to protects Division 2 rated equipment in Division 1 or zone 1 Areas. This system reduces the classification within protected enclosures from Division 1 to Division 2 or zone 1 to zone 2. All protected equipment must be rated for Division 2. Automatic power control disconnects are not required, but visual and/or audible alarms must be initiated when the pressure falls below the minimum limit.

Panel / System with Type "Z" Pressurization is used to protects general-purpose equipment in Division 2 or zone 2 Areas. This system reduces the classification within protected enclosures from Division 2 or zone 2 to non classified (non hazardous). Automatic power control disconnects are not required, but visual and/or audible alarms must be initiated when the pressure falls below the minimum limit.

Basic differences between X, Y and Z Panel / System as per NFPA 496:

1. For Type X and Z systems, the internal equipment can be rated as general purpose equipment, but for Type Y systems only Division 2 rated equipment can be used.

2. The purging time for Type Y and Z is based on a measured inlet airflow rate to the enclosure. Type X purging time is based on a measured airflow rate to the outlet.

3. The removal of power to the enclosure is not required on loss of pressure for Type Y and Z systems. Since a Type X systems may have non-hazardous rated internal equipment in a Division 1 area, an interlock between the power and pressurization system is required to cut off power to this internal equipment in case of lost internal pressure.

     4. Type X systems also require electronic timers for full automatic control.