A pump does not completely convert the kinetic to pressure energy. Some of the energy is always lost internal and external in the pump.
Internal losses
- hydraulic losses - disk friction in the impeller, loss due to rapid change in direction an velocities through the pump
- volumetric losses - internal recirculation at wear rings and bushes
- mechanical losses - friction in seals and bearings
The efficiency of the pump at the designed point is normally maximum and is called the
- Best Efficiency Point - BEP
Labels: pumps
Typical properties of alloy steels
| Content | Type | Specification | Tensile strength (Nmm-2) | Fatigue limit (Nmm-2) | Weldability | Corrosion resistance | Machine ability | Formability |
| Low | 1 %Cr, Mo | 709M40 | 1240 | 540 | PH/FHTR | PR | F/HTR | F |
| Low | 1.75%Ni,Cr,Mo | 817M40 | 1550 | 700 | PH/FHTR | PR | P/HTR | F |
| Low | 4.25%Ni,Cr, Mo | 835M30 | 1550 | 700 | PH/FHTR | PR | P/HTR | F |
| Low | 3%Cr, Mo, V | 897M39 | 131(1780) | 620 | PH/FHTR | PR | P/HTR | F |
| Low | 5%Cr, Mo, V | AISI HI 1 | 2010(A2630) | 850 (A1880) | PH/FHTR | PR | P/HTR | F |
| Medium | 9%Ni, Co | HP9/4/45 Republic Steel | 1390 (1850) | - | FHTR | PR | P/HTR | F |
| Medium | 12-14%Cr | 410S21 | 1160 | 340 | P/FHTR | F | F/HTR | F |
| Medium | Cr, W, Mo. V | Vascojet MA, Vanadium | 2320 (A3090) | 960 | PH/FHTR | PR | P/HTR | F |
| High | 13%Cr, Ni, Mo | 316S12 | 620 | 260 | G | G | F | G |
| High | 19%Cr,Ni, Mo | 317S16 | 650 | 260 | G | G | F | G |
| High | 15%Cr, Ni, Mo, V | ESSHETE 1250 S. Fox | 590 | - | G/FHTR | G/HT | F | - |
| High | 17%Cr,Ni | AISI 301 | 740(CR1240) | 280 | F | F | F | G |
| High | 17% Cr, Ni, AI | 1717 PH Armco | 1480 | - | F | F | F | G |
| High | 14%Cr, Ni, Cu. Mo, Nh | REX 627 Firth Vickers | 1470 | 540 | FHTR | F | F | F |
| High | 15%Cr, Ni, Mo, V | AM 355 Allegheny Ludlum | 1480 | 740 | FHTR | F | F | F |
| High | 18%Ni, Co, Mo | 300grade maraging INCO | 1930 | - | G/FHTR | PR | F | P |
| High | 18%Ni, Co, Mo | 250grade maraging | 1700 | 660 | G/FHTR | PR | F | P |
A = ausformed, MA = martempered, CR =cold rolled, P = poor, F = fair, G = good, PH = preheat required, PR = protection required, HT = at high temperature, HTR = when heat treated, FHTR=final heat treatment required.
Labels: engineering materials