Kidde Fire Systems Surge Protector P/N 81-CO2MAN-001 Manuale Utente

September 2013

4-36

P/N 81-CO2MAN-001

Figure 4-28.  Pneumatic Detector (HAD)

4-4.9.2

TUBING
The response time of a pneumatic detection system is dependent upon a number of factors, 

such as:     

a. fire intensity
b. HAD spacing and location
c.

control head setting and vent size

d. volume of copper tubing

It is important to remember that the system will actuate when the entire sensing volume

(HADs, copper tubing, and pneumatic-control-head sensing chamber) is pressurized to a level 

equal to the control-head setting (e.g. 4 inches of water). To ensure a fast response to rapidly 

progressing or intense fires, the tubing system must be limited to a total length of 200 feet or 

less of 1/8-inch O.D. copper tubing for a single-line system, or a total length of 200 feet or less 

of 1/8-inch O.D. copper tubing for each line of a multiple control head system.
1/8-inch copper tubing is used in industrial systems to interconnect the HADs to the pneumatic 

control head(s) or a pneumatic main-reserve transfer valve.
Note: The final leg of the copper tubing system connects to the pneumatic control head by 

means of 3/16-inch O.D. heavy wall copper tubing provided by Kidde Fire Systems.