- Author
-
Isaksson, S.
|
Holmberg, L.
|
Jacobsson, P.
- Title
- Sprinklersystems vattentillopp: tillforlitlighet. [Sprinkler System Water Supply Reliability.]
- Coporate
- Swedish National Testing and Research Institute, Boras, Sweden
- Report
-
SP Report 1998:12,
1998,
46 p.
- Distribution
- For more information contact: SP Swedish National Testing and Research Institute, Box 857, SE-501 15 BORAS, Sweden. Telephone: +46 33 16 50 00, Fax: +46 33 13 55 02, Email: info@sp.se Website: http://www.sp.se/eng/default.htm
- Keywords
-
sprinkler systems
|
water supply
|
reliability
|
sprinklers
|
pumps
|
valves
|
statistical analysis
- Identifiers
- strainers
- Abstract
- ONLY ABSTRACT IN ENGLISH: The reliabilty of water supply sources for sprinkler systems have been investigated, Various system designs have been modeled using fault tree analysis with reliability data obtained from the literature. In addition a questionnaire was sent out to a selection of certified sprinkler system inspectors. The experience reflected in the answers was incorporated in the choice of the data used in the calculations. The data from the calculations and the feedback from the inspectors correlated well as a whole though the calculations on systems with municipal pipe supply and open water source overestimated the reliability. In the calculations any decrease in water capacity below the design was considered a fault. The systems where modeled not including the alarm valve since these can be of different types and are a common component in all systems. Reliability data for alarm valves are however included in the report. From the calculations it is evident that a simplification of the water supply source, as for example having only one pump or a municipal water mains fed from only one source will affect the system reliability in a negative way. More so by having only one pump than from having only one municipal water feed. Actually, in many cities, the municipal water supply is so reliable that the overall reliability of the system is comparable with a system with two pumps that takes its water from an open water source. None of the dominating reasons for faults are related to low quality of components, but rather to poor maintenance routines, and that the prescribed'frequency of inspection is not adhered to by the system owner. Therefore the reliability of sprinkler systems can be increased substantially by better inspection and maintenance routines. One source indicates that decreasing the interval between inspections from every three months to every week increases the reliability by a factor of six to eight. This report can provide a basis for the choice of performance based, simplified, less costly or more reliable water supplies for applications where an analysis of the hazard or the risk identifies the need for this.