2-FT. NPSH PUMPS
Bulletin 191A

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 the 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).

* Boiling point of water under atmospheric pressure at sea level.

2-FT. NPSH PUMPS

There are many applications where the water to be pumped is close to its boiling point (212°F) and where it is not practical to raise the suction source sufficiently high above the pump centerline.

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 pumps are available in the following types:
CCS, CGS & CKS - horizontal close-coupled for base mounting.
CCSF, CGSF & CKSF - vertical close-coupled for flange mounting on the side of a tank.
CCSB, CGSB & CKSB - horizontal flexible coupled for base mounting.

These 2-FT. 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.

List Prices

To determine the list prices of 2-Ft. NPSH Pumps, make the following LIST PRICE ADDITIONS to the list prices shown on the price pages for the type CC pumps. For flange mounted pumps, the flange additions are included in the prices shown below. Also make the applicable weight additions.

NOTES:
1. Standard pump performance curves and selection tables apply to 2-ft. NPSH pumps.
2. The letter 'S' had been added to model numbers of these pumps to indicate the addition of the suction inducer.
3. For modifications and accessories, see price pages for type CC pumps.
4. For parts prices, see parts list pages type CC pumps,  plus parts prices shown on this page.
5. Pump sizes not shown above are not currently available in this format.
6. CGS and CKS pumps can be substituted for the standard CC, CG and CK pumps used on CCH condensate return units and BFC boiler feed units. Use applicable list price and weight differentials.
7. CGSF and CKSF pumps can be substituted for the standard CCF, CGF and CKF pumps used on CCV condensation return units and BFV boiler feed units. Use applicable list price and weight differentials.

For parts not shown above, refer to CC/CG/CK parts price pages.

When ordering parts, furnish the pump model number and record number from the nameplate.

For list prices of bronze parts not shown above, multiply the price of the equivalent cast iron part by 2.5