Technical data
2.2 Releasing Devices
A releasing device serves to vent hydraulic pressure from the main system control valve push-rod chamber
allowing the Model DDX Deluge Valve to open and flow water into the fire protection system. They can be
classified as either manual or automatic, and can be used in various combinations to achieve the desired
level of operational safety.
2.2.1 Sprinklers
Any closed automatic fire sprinkler can be used as a thermal detector whenever hydraulic (wet pilot)
or pneumatic (dry pilot) activation of the primary control valve is desired. Although a large variety of
sprinkler temperature ratings exist, ratings between 135°F (57°C) and 212°F (100°C) are most com-
mon for use in wet or dry pilot lines. Reliable Automatic Sprinkler Company Bulletins 013, 110, 014 &
131 illustrate suitable standard spray sprinklers for use as pilot line detectors. The Model G sprinklers
(Bulletin 110) may be coated with wax or lead for corrosion resistance.
Quick response sprinklers installed in wet or dry pilot
lines may be desirable as a means for hastening opera-
tion of a thermal detection system. Sprinkler models GFR
and F1FR sprinklers are described in Reliable Automatic
Sprinkler Company Bulletins 131 and 014, respectively.
Quick Response sprinklers, however, cannot be wax or
lead coated for corrosion-resistance.
Sprinklers used as thermal detectors must be spaced
according to NFPA 13 sprinkler spacing requirements.
Generally speaking, sprinklers on the pilot lines must be
spaced the same as the sprinkler spacing required for
the hazard to be protected. For additional pilot line in-
formation, refer to Reliable Automatic Sprinkler Company
bulletins for deluge systems (516 through 519) and single
interlock preaction systems (749), paying special atten-
tion to maximum elevation and length limitations for wet
pilot lines. NFPA 13 Standard for the Installation of Sprin-
kler Systems and NFPA 15 Water Spray Fixed Systems for
Fire Protection provide additional information on the use
of automatic fire sprinklers on pilot lines for system actuation.
2.2.2 Pilot Line Detectors
Similar to automatic fire sprinklers, pilot line detectors such as the Reliable F1-FTR Pilot Line Detector
can be used for systems utilizing hydraulic (wet pilot) or pneumatic (dry pilot) actuation. The FTR incor-
porates a 2.5 mm glass bulb with a Model F1 sprinkler frame, and is identified as a Fixed Temperature
Release (FTR) to differentiate it from standard sprinklers. The FTR is made of die cast brass and is
available in various finishes. During fire conditions the heat sensitive liquid in the bulb expands, the
bulb shatters and releases the cap and spring assembly. This vents the hydraulic or pneumatic pres-
sure in the pilot line, and in turn the pushrod chamber. The water pressure from the pushrod chamber
discharges to a drain, allowing the Model DDX Deluge Valve to open and fill the system piping.
The F1-FTR can be installed at greater spacing than regular sprinklers used on a pilot line. Refer to
Reliable Automatic Sprinkler Company Bulletin 180 for specific listing and in-
stallation limits. Similar to a glass bulb sprinkler, the F1-FTR must be installed
in accordance with NFPA-13 installation specifications to prevent possible
damage to FTR. Before installing the F1-FTR the appropriate temperature
rating must be determined. The temperature rating should be lower than the
temperature rating of system sprinklers or nozzles.
The F1-FTR can be installed in any position; however, in locations where the
pilot line system is exposed to freezing conditions install them in the upright
position only. Wet pilot lines must be installed where there is adequate heat
to avoid possible freezing. An F1-FTR that may be subject to mechanical
damage must be protected by the appropriate sprinkler guard (see Reliable
Automatic Sprinkler Company Bulletin 208) for the F1 Model.
Approvals and technical data for the Reliable Automatic Sprinkler Company
Model F1-FTR Pilot Line Detector can be found on Bulletin 180.
27.
Figure 23
Figure 24