Technical data

TECHNICAL DATA
The Viking Corporation, 210 N Industrial Park Drive, Hastings MI 49058
Telephone: [phone] Technical Services 877-384-5464 Fax: [phone] Email: [e-mail]
PREACTION SPRINKLER
SYSTEM
Page 46
February, 2010
Figure 21
Figure 22: Model C-1 Thermostatic Release
Figure 23
Releasing devices, including automatic sprinklers used as releasing devices, are listed with specific spac-
ing requirements that must be followed. Any listed sprinkler can be used on the system, however, Viking
recommends the Microfast
®
Model M Fixed Temperature Release because of its maximum spacing allow-
ance (Figure 21). NOTE: Where thermal activation is utilized, the activation temperature of the release
system shall be lower than the activation temperature of the sprinkler to allow the releasing device to oper-
ate before the sprinkler system. While simple, using automatic sprinklers as a method of release may not
be fast enough in many situations.
To speed up system operation, the most common release device utilized is the Viking Model C Rate of
Rise Release. The Model C will activate the system when the temperature in the protected area increases
at a rate of more than 15 °F per minute. Pressure from the release line flows through a small hole in the
release’s diaphragm to exert pressure on the diaphragm, forcing the clapper in the release closed against
its seat. The mechanics of release operation begin with a rapid change in temperature. When the release is
subjected to a rate of temperature increase greater than 15 °F per minute, the tube element expands more
rapidly than the rod element because of its relatively large surface area and small mass (Figure 22).