Open Type

The principle of operation of the hydraulic reciprocating pump is similar to the beam pump, with a piston-like sub-surface pump action. The energy to drive the pump, however, is delivered through a hydraulic medium, the power fluid, commonly oil or water. The power fluid drives a downhole hydraulic motor which in turn drives the pump. A separate surface pump delivers the hydraulic power. The power fluid system can be of the closed loop or of the open type. In the latter case, the power fluids are mixed with the produced fluid stream. The performance of the hydraulic pump is primarily monitored by measuring the discharge pressures of both surface and sub-surface pumps. 

Using other criteria, compressors are classified as open, semiher-metic accessible), or hermetic. Open type is characterized by shaft extension out of compressor where it is coupled to the driving motor. When the electric motor is in the same housing with the compressor mechanism, it could be either hermetic or accessible (semihermetic). Hermetic compressors have welded enclosures, not designed to be repaired, and are generally manufac tured for smaller capacities (sel-... 

Curves h to e are for turbines located at a distance C = d or greater from tbe bottom of tbe vessel. For disk flat-blade turbines, curve c, there is essentially no effect of d /dj in tbe range 0.15 to 0.50. For open types, curve h, tbe effect of d /dj may be strong, depending upon tbe group nh/dt. 

Open Type This type of assembly is without an enclosure, as used in an outdoor switchyard or as mounted on a pole, such as a gang-operated switch,... 

These transformers are three-phase and may be connected for zig-zag or star/delta connections (Section 20.9.1). The delta may also be made open type by inserting a resistor across it to help adjust the zero-sequence impedance, if required. 

In humid and corrosive conditions, aluminium erodes faster than copper. These solid or hollow conductors connect the stipply side to the receiving end and are called bus ducts. They may be of the open type, stich as are used to feed a very high current tit very low voltage. A smelter unit is one such application. Btit nonnally they are housed in a sheet mettil enclostiie.. See Figtires 28.2(a) and 28.33(b). 

Dry feeding requirements are similar to those for dry alum except that belt-type feeders are rarely used because of their open type of construction. Closed construction, as found in the volumetric and loss-in-weight-type feeders, generally... 

Many preliminary analyses of gas turbines are based on the assumption of a closed air standard cyclic plant, and for such analyses the use of tj as a thermal efficiency is entirely correct (as discussed in the early part of Chapter 3 of this book). But most practical gas turbines are of the open type and the rational efficiency should strictly be used, or at least its approximate form, the arbitrary overall efficiency tjq. We have followed this practice in the latter part of Chapter 3 and subsequent chapters even though some engineers consider this differentiation to be a somewhat pedantic point and many authors refer to tjo as a thermal efficiency (or sometimes the lower heating value thermal efficiency ). 

It is evident, that all of the abovementioned relates to the reaction of cycle opening type and the formation of active centers (radicals) at molecule ends ... 

Figure 3-2. Cut-a-way section of single-stage pump. Part 1 (above) enclosed type impeller. Part 2 (lower left) open type impeller. (Courtesy Peerless Pump Div. FMC Corp.)...

Wearing plates With open type impellers or end clearance wearing fits, these perform the same purpose as wearing rings do with radial clearances. 

Pulpy solids such as paper stock Single suction. Double suction only used on very slight solids concentrations and then with special end clearance wearing fits. Closed. Open type used to be standard but change to end clearance wearing fits made closed impellers better suited. 

Whenever possible the individual installation of valves is preferred, and these should be connected directly to the vessel or pipe line [1, 28]. If a block-type valve is considered necessary for a single valve installation, it must be of the full open type, and locked open with the key in responsible hands, as stated earlier. 

Most ventilators are powered in one direction with spring return. Thus, a pneumatic ventilator might be described as pressure to open or pressure to close. With the pressure to open type the ventilator will fail to the closed position under the influence of the return spring, ensuring the building remains weatherproof. Where ventilators are installed mainly as smoke ventilators it is important that they fail to the open position, so pressure to close ventilators should be used. A fusible link is normally fitted into the controls so that in the event of fire, affected ventilators will open automatically to release smoke and heat. 

The pore space of a soil may contain either water or a gaseous atmosphere. Thus the aeration of a soil is directly related to the amount of pore space present and to the water content. Soils of fine texture due to a high clay content contain more closely packed particles and have less pore capacity for gaseous diffusion than an open-type soil such as sand. 

When ejectors pull non-condensables and other vapors from a direct contact water condenser (barometric, low level jet, deaerator) there is also a release of dissolved gases, usually air, from water. This air must be added to the other known load of the ejector. Figure 6-22 presents the data of the Heat Exchange Institute [10] for the amount of air that can be expected to be released when cooling water is sprayed or otherwise injected into open type barometric or similar equipment. 

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