Power

The power end contains the crankshaft, connecting rods, crossheads, pony rod, bearings, and frame (see Figures 14 and 15). Basic designs are horizontal and vertical with sleeve or antifriction bearings. Some have integral drive gears.

Frame The frame absorbs the plunger load and torque. Vertical pumps with outboard packed stuffing boxes (refer to Figure 2) have the frame in compression (refer to Figure 14). With horizontal single-acting pumps, the frame is in tension (refer to Figure 15). Frames are usually close-grain cast iron with relatively thick cross-sections. This combination provides superior dampening for the normal low-frequency cyclic loading. Some intermittent duty pumps, specifically designed for mobile services, are constructed of lighter weight, fabricated steel plate.

The frame is usually vented to the atmosphere. However, when the atmosphere is detrimental to the working parts of the frame, such as an ammonia attack on bronze bearings, the frame can be purged continuously with nitrogen gas.

Crankshaft The crankshaft (see Figures 16, 17, and 18) varies in construction, depending on the design and power output of the pump. In horizontal pumps, the crankshafts are usually of nodular iron or cast steel. Vertical pumps use forged steel or machined billet crankshafts. Because the crankshafts have a low mass and operate at relatively low

FIGURE 12 Separate suction with an integral FIGURE 13 A plunger cover (FWI)

discharge manifold (Gardner-Denver)

FIGURE 12 Separate suction with an integral FIGURE 13 A plunger cover (FWI)

discharge manifold (Gardner-Denver)

speeds, counterweights and flywheels are not used. Except for duplex pumps, the crankshaft always has an odd number of throws to obtain the best flow pulsation characteristics. The firing order in a revolution depends on the number of throws on the crankshaft (see Table 3).

The crankshaft main and rod-bearing surfaces are ground to a 16 rms surface finish or better. Large radii are used where journal diameters intersect with the adjacent cheeks to

FIGURE 15 A horizontal pump power end (Flowserve Corporation)
FIGURE 16 A cast crankshaft (Flowserve Corporation)

FIGURE 17 A crankshaft machined from a billet (Flowserve Corporation)

FIGURE 17 A crankshaft machined from a billet (Flowserve Corporation)

FIGURE 18 A cast crankshaft with integral gear (Continental-EMSCO)

3.2 POWER PUMP DESIGN AND CONSTRUCTION TABLE 3 Order of Pressure Build-up or Firing Order

No. of Pressure build-up order

Throw from plungers pulley end or pistons 123456789

Throw from plungers pulley end or pistons 123456789

Duplex

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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