Bermad FP-400E-7DM Double Interlock Pre-action Electric-Pneumatic Release System



Bermad FP-400E-7DM Double Interlock Pre-action Electric-Pneumatic Release System

The Bermad Model FP 400E-7DM Double Interlock Pre-action, Electric-Pneumatic Release System is suitable for use in systems requiring that water be kept out of the sprinkler piping until an electric detecting device and a sprinkler have both been activated.

Electric-pneumatic double interlock systems include automatic sprinklers attached to a dry sprinkler piping system, with a supplementary electric detection system and a Pneumatic Supervised System of air pressure in the system piping, installed in the same area.

The Supervised System consists of a Pneumatic Pilot Valve (PORV), pneumatic low-pressure supply and an additional listed check valve—including trim with low-pressure switch—installed downstream from the Preaction Valve. The Double Interlock Electric-Pneumatic System admits water into the sprinkler piping only when the detection system triggers the solenoid through the control panel, while simultaneously the PORV is activated due to the supervised system pressure drop.


  • Latch open - Closes only upon local reset
  • Factory pre-assembled trim – Out-of box-quality
  • In-line serviceable – Minimal down time
  • In-line Check Valve – intermediate vented chamber- Anti flooding
  • One-piece molded elastomeric moving part –No maintenance required



In the SET position, the line pressure supplied to the main valve’s control chamber [1] via the priming line [2] and through an EasyLock Manual Reset [3], is trapped by the EasyLock internal check valve, by a closed Solenoid Valve [4] and by a closed Manual Emergency Release [5]. The trapped pressure holds the main valve’s diaphragm and plug against the valve seat [6], sealing it bubble tight. The piping system is filled with monitored low air pressure to ensure all sprinklers [F] are sealed. An intermediate vented chamber is created by an in-line swing check valve [7], and a Normally Open drip-check [8]. In the event of FIRE, automatic sprinkler activation causes a pneumatic pressure drop that opens a Pneumatic Pilot Valve (PORV) [9] and activates air pressure switch low [10], while the main valve remains closed. Only when both the PORV and the Solenoid Valve open (triggered by the electric detection system [E], through a control panel [C]), pressure is released from the main valve’s control chamber, through the opened Solenoid Valve and PORV (or the Manual Emergency Release). The EasyLock prevents line pressure from entering the control chamber, allowing the preaction valve to latch open and water to flow into the system piping and to alarm device [11].


Bermad FP-400E-7DM Double Interlock Pre-action Electric-Pneumatic Release System Bermad FP-400E-7DM Double Interlock Pre-action Electric-Pneumatic Release System Brochure