The trim set used with the DDX-LP Dry Pipe Valve contains the LP Dry Valve Actuator releasing device. This Actuator allows the system’s air or nitrogen pressure requirement to be considerably less than the available water supply pressure (see table). The following benefits are a direct result of lower air pressure:
1. In refrigerated area systems, lower air pressure decreases the possibility of ice plugs, which could impede or prevent the flow of water to sprinkler heads in the event of fire.
2. Lower air pressure (volume) will enable smaller capacity, lower cost dehydration equipment when it is required.
3. Lower air or nitrogen pressure can reduce water delivery time when the system actuates, and in some cases, may eliminate the need for an accelerator.
4. Low pressure requirements make the use of dry nitrogen gas, instead of air, practical even on larger systems. Resulting benefits include a lower-than-air dew point, which minimizes ice plugging of system lines and enhances “user friendliness” during installation and operation.
5. System maintenance is simplified since priming water is not required and the Dry Pipe Valve can be reset externally without cover removal. This is accomplished by pushing in and turning the external reset knob at the rear of the Dry Pipe Valve (see Fig.1). This feature provides a significant system-restoration time advantage.
The DDX-LP Dry Pipe Valve’s trim set (see Fig.2) provides all of the necessary equipment for connections to the pushrod chamber’s inlet and outlet ports, the 1 1/4” (30mm) main drain, alarm devices, air supply, water supply and required pressure gauges. This trim set is available in individual parts, in time-saving, segmentally assembled kit forms, or fully assembled to the DDX-LPDry PipeValve (with or without a control valve). All the sizes of the DDX-LP Dry Pipe Valve trim sets may be equipped with the optional Accelerator, trim kit. This device acts as an exhauster which will hasten the operation of the LDX Dry Valve Actuator and minimize the water delivery time for the entire system.