Features
NET POSITIVE SUCTION HEAD (NPSH)
NPSH is the force which causes a liquid to flow into the suction eye of a centrifugal pump impeller.
There are two NPSH values which must be considered. First is the NPSH REQUIRED by the pump, which is a function of the pump design. Second is the NPSH AVAILABLE to the pump, which is a function of the system design.
The NPSH AVAILABLE must be greater than or equal to the NPSH REQUIRED, or cavitation (bubble formation) may occur in the impeller eye, causing the pump to malfunction.
The NPSH REQUIRED is read from pump performance curve. The NPSH AVAILABLE is the static head (height of the suction source above the pump centerline) plus the temperature head available from the water (see table below).
Features Table
| water temperature in farenheight | temp. head available I feet (sea level) | ||
| 50 | 34 | ||
| 60 | 33 | ||
| 70 | 33 | ||
| 80 | 33 | ||
| 90 | 32 | ||
| 100 | 32 | ||
| 110 | 31 | ||
| 120 | 30 | ||
| 130 | 29 | ||
| 140 | 27 | ||
| 150 | 25 | ||
| 160 | 23 | ||
| 170 | 20 | ||
| 180 | 17 | ||
| 190 | 12 | ||
| 200 | 7 | ||
| 210 | 1 | ||
| 212* | |||
| 220 | -6 | ||
| 230 | -14 | ||
| 240 | -24 | ||
| 250 | -35 |
Features Text
2-FT. NPSH PUMPS
There are many applications where the water to be pumped is close to its boiling point (212 degrees F) and where it is not practical to raise the suction source sufficiently high above the pump center-line.
For such applications, Federal has developed its 2-FT NPSH PUMPS. These pumps have a centrifugal main impeller plus an axial flow suction inducer impeller, so that they are capable of operating with 2-ft. of NPSH available to the pump.
These are available in the following types:
CCS, CGS and CKS -horizontal close-coupled for base mounting.
CCSF, CGSF and CKSF -vertical close-coupled for flange mounting on the side of the tank.
CCSB, CGSB, CKSB -horizontal flexible coupled for base mounting.
These 2FT. NPSH PUMPS can be substituted for the standard pumps, if preferred, on CCV and CCH condensation return units and BFV and BFC boiler feed units.
Highlights
- 2 ft. NPSH pumps
- Pumping fluids close to boiling point
- Axial flow suction inducer impeller