Special Hazards / Special Systems: Double Interlock Preaction Systems
![B-720-Preaction-1.5](/images/stories/data_sheet/water_system/reliable/special%20Hazard/double%20interlock/B-720-Preaction-1.5.jpg)
Double Interlock Preaction System -Type D - 1-1/2" (40mm) Data sheet
![B-713-Preaction-System-2.5](/images/stories/data_sheet/water_system/reliable/special%20Hazard/double%20interlock/B-713-Preaction-System-2.5.jpg)
Double Interlock Preaction System - Type D - 2-1/2" (65mm) Data sheet
![B-737CVRA-new](/images/stories/data_sheet/water_system/reliable/special%20Hazard/double%20interlock/B-737CVRA-new.jpg)
Double Interlock Preaction System - Type D - 2", 2-1/2", 3" & 76mm - DDX Valve Data sheet
![B-738CVRA](/images/stories/data_sheet/water_system/reliable/special%20Hazard/double%20interlock/B-738CVRA.jpg)
Double Interlock Preaction System - Type F - 2", 2-1/2", 3" & 76mm - DDX Valve Data sheet
![B-728-Preaction-System-4-6](/images/stories/data_sheet/water_system/reliable/special%20Hazard/double%20interlock/B-728-Preaction-System-4-6.jpg)
Double Interlock Preaction System - Type D - 4" & 6" (100mm & 150mm) - DDX Valve Data sheet
![B-729-Preaction-System-4-6](/images/stories/data_sheet/water_system/reliable/special%20Hazard/double%20interlock/B-729-Preaction-System-4-6.jpg)
Double Interlock Preaction System - Type F- 4" & 6" (100mm & 150mm) - DDX Valve Data sheet
![B-744-Double-Interlock-Preaction-Type-D-8in](/images/stories/data_sheet/water_system/reliable/special%20Hazard/double%20interlock/B-744-Double-Interlock-Preaction-Type-D-8in.jpg)
Double Interlock Preaction System - Type D - 8" (200mm) - DDX Valve Data sheet
![B-745-Double-Interlock-Preaction-Type-F-8in](/images/stories/data_sheet/water_system/reliable/special%20Hazard/double%20interlock/B-745-Double-Interlock-Preaction-Type-F-8in.jpg)