NFPA өрт сорғы тобы

What is NFPA?
The National Өрттен қорғау Association (NFPA), founded in 1896 in the United States, is widely accepted worldwide for its publications, programs and standards on fire and occupational safety. Training based on these standards improves practical application on projects.

What is NFPA 20?
NFPA 20 (Standard for the Installation of Centrifugal Fire Pumps) defines specifications, performance and installation rules for өрт сорғылары, сорғы sets, motor control systems and the ancillary components that must be used.

Desan Engineering жеткізеді өрт сорғысы groups manufactured in line with NFPA 20–oriented requirements for stationary ӨРТТЕН ҚОРҒАУ systems.

Highlights

• Separate controller for each сорғы
• Shut-off pressure not exceeding 1.4× rated pressure
• At 1.5× rated flow, pressure not less than 0.65× rated pressure
• Suction pipe velocities below 4.57 m/s (15 ft/s)
• Bearings with minimum 5,000-hour service life
• Bronze impeller; shaft AISI 316 or AISI 304; casing GG-25 шойын
• Sealing with five-ring soft packing in Серия Өнімion
• Electric motor service factor not exceeding 1.15
• Flanges to DIN 2533 / PN 16 (suction & discharge typically TS EN 1092-2 / PN 16 on horizontal end-suction platforms)

End-suction ортадан тепкіш өрт сорғысы set
Fire groups are commonly built on horizontal end-suction ортадан тепкіш hydraulics: single-stage, volute casing, closed impeller, coupling drive between motor and сорғы shaft. Soft packing is standard; mechanical seal can be supplied on request. Back-pull-out style access allows seal, shaft, bearings and impeller service without removing the volute from the piping. Rotation is counter-clockwise from the suction side; bearing housing is externally lubricated with an oil sight glass.

Electric motor driven өрт сорғысы sets
For maintenance, it is important that the сорғы can be serviced without full system dismantling. A jockey (leak) сорғы handles minor system leaks before the main сорғы starts, avoiding unnecessary main-сорғы cycles. Where mains power fails and a generator does not start, a diesel-driven өрт сорғысы can back up the electric set. Pressure switches support backup sequencing between units. Gate клапандар are preferred on the suction line; vacuum and pressure gauges monitor suction and discharge. Cooling-related клапандар on the set are kept closed in normal fire-сорғы duty. Multi-сорғы arrangements are typically designed for 100% redundancy so another unit can take over on failure. The fire suppression installation should resist horizontal seismic loads up to 0.5× its weight.

Diesel engine driven өрт сорғысы sets
In fire prevention systems, сорғылар are often used with 100% redundancy, and many sets are diesel-engine driven. NFPA 20 determines when an engine-driven сорғы is required. For electric сорғылар, relief-клапан setting at shut-off is typically 1.21× shut-off head, with the клапан on the discharge side. Desan Engineering uses spring-loaded Ағызу клапаныs in fire suppression packages.