Fire Protection Systems by A. Maurice Jones Jr.;

Author:A. Maurice Jones Jr.;
Language: eng
Format: epub
Publisher: Jones & Bartlett Learning LLC
Published: 2021-07-15T00:00:00+00:00

FIGURE 7-20 By looking closely at a sprinkler head, a person can determine the manufacturing year, type, model, listing and approvals, sprinkler identification and control numbers, K-factor, temperature rating, and manufacturer.

© A. Maurice Jones, Jr./Jones & Bartlett Learning.

FIGURE 7-21 Heads manufactured after 2001 were required to have a sprinkler identification number. The sprinkler identification number for this head is V2734.

© A. Maurice Jones, Jr./Jones & Bartlett Learning.

All of this information is important, but the type of head, temperature rating, and K-factor are critical to the design process. Installing a head that has the wrong temperature rating for the installation conditions could lead to unwanted activation, delayed activation, or no activation. During construction it is important for the installer to verify that the temperature rating of the head is as indicated on the approved plans. Once the building is occupied, the responsible party must also verify this information whenever a sprinkler head needs changing. The temperature rating may appear as engraved text on the head; as a particular paint color applied to the head; or, in the case of glass bulb sprinkler heads, as a particular color of the bulb. The 2019 edition of NFPA 13, Table 7.2.4.1, lists the temperature ratings, classifications, and color codes for sprinkler heads. For example, examination of the table shows that a sprinkler head with a temperature activation range between 175oF and 225oF) is classified in the intermediate range. An intermediate range head using a glass bulb requires either a yellow or green color liquid, but a head without a glass bulb will require white paint to be applied, typically, to the frame of the head.

For calculation and design purposes, the K-factor establishes the mathematical relationship between the pressure and flow from a sprinkler head. With Q being the discharge in gallons per minute, K being the discharge coefficient for the orifice of the sprinkler head, and P being the water pressure in pounds per square inch, the relationship for determining flow is expressed in the following formula:

Q = K √ P

Each size orifice has a K-factor value that applies when performing hydraulic calculations. For example, a ½-in. orifice has an applied nominal K-factor of 5.6, a ¾-in. orifice has a nominal K-factor of 14.0, and a 1-in. orifice has a nominal K-factor of 25.2 FIGURE 7-22.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.