Grundfos Submersible Recirculation Pumps

Performance overview

For further details about the SRP performance ranges, see curves for: > SRP.xx.30.xxx.25 (PDF size: 2,45 MB) > SRP.xx.50.xxx.27 (PDF size: 2,45 MB) > SRP.xx.80.xxx.11 (PDF size: 2,45 MB) > Performance overview, 60 Hz (PDF size: 697 KB) > SRP.xx.30.xxx.25 (PDF size: 697 KB) > SRP.xx.50.xxx.27 (PDF size: 697 KB) > SRP.xx.80.xxx.11 (PDF size: 697 KB)

Material specifications and type key

Material specifications

Component Material DIN W.-Nr./EN standard AISI/ASTM Bottom fixation Stainless steel 1.4301 304 Column profile tube Stainless steel 1.4301 304 Top fixation Stainless steel 1.4301 304 Connection flange PN 10 2/3 Stainless steel 1.4301 304 Relief wire Stainless steel 1.4404 316L Crane w/winch Aluminium - - Pump rack Stainless steel 1.4301 304 Motor housing Cast iron EN-JL1040 - Gear housing Cast iron EN-JL1040 - Hydraulic inlet Stainless steel 1.4301 304 Impeller Stainless steel 1.4581 -

Corrosion protection To ensure long and trouble-free operation, the cast-iron parts are protected against corrosion by a high-grade multi-layer corrosion system. Anti-corrosive protection of submerged components: Two-component epoxy coating free from tar. Minimum thickness 320 μ. Complies with the AA 423 standard. Type key

Selection guide

Head loss calculation Pump selection is best carried out when the flow and head have been accurately determined. The data needed in order to select the SRP with the right specifications are: Required flow, Q – and total head, H. Calculation of head H = Hgeo + Hsystem, where Hgeo is the geodetic head (Hgeo = H2 - H1) and Hsystem is Head Loss in the system: Hsystem = Hj + Hjn + Hvalve Hj = Loss in pipe. Hj = λ x (LxV2 / D x 2g) Hjn = Outlet loss. Hjn = V2 / 2g Loss in elbows. Typical value 0.1 – 0.2 m Hvalve = Loss in valve. Typical value 0.05 – 0.25. It is important to use actual data from the valve supplier. For more specific calculation please contact Grundfos. Symbols: λ = Friction factor - typical value 0.02 L = Pipe length [m] V = Velocity [m/sec] D = Pipe diameter [m] g = Gravity 9.81 Example: Q = 475 l/sec Hgeo = 0.35 m L = 21 m V = 2.4 m/sec D = 0.5 m There are no valves or elbows in the system. Calculation of loss in pipe: Hj = 0.02 x (21 x 2.42 / 0.5 x 2 x 9.81) = 0.25 m Calculation of outlet loss: Hjn = 2.42 / 2 x 9.81 = 0.30 m Determination of Head H = 0.35 m + 0.25 m + 0.3 m = 0.9 m By using the selection curves for SRP.XX.50.XXX.27 we can determine that the SRP.80.50.378.27 meets the requirements and will deliver Q = 475 l/sec at H = 0.95 m. For more details, see the information on the SRP series in WebCAPS or the SRP product brochure.