Pump Design Standardization

Certain pump designs have been standardized lo aid manufacturer s problems, and to allow the owners to take advantage of standardization of parts and dimensions, and consequently maintain a more useful inventory. The standards are sponsored through the American National Standards Institute however, many manufacturers also produce to the American Petroleum Institute and their own proprietary standards. These are special pumps that do not conform to all the standards, but are designed to accomplish specific pumping services. 

The primary pump types for the chemical industry for horizontal and vertical inline applications have been standardized in ANSI B-123, ANSI Std B73.1M for horizontal end suction centrifugal pumps, and ANSI B73.2M for vertical inline centrifugal pumps. The standards are in a continuous process of upgrading to suit requirements of industry and the manufacturers. The API-610 standard is primarily a heavy duty application, such as is used for the refinery and chemical industry requirements. This is the only true world pump [21] standard, although the International Organization for Standardization (ISO) is studying such an improved design [20], 

The standards are important because they allow the dimensional interchangeability of pumps and shaft packing of different manufacturers, but only as long as the manufacturers conform to the standard. 

All of the bushings as well as the liner ring and thrust ring are not attached by sdhesives. Thus the parts are easily replaced and the psrts are free from any weakness of the adhesive. 

Standard materials other materials available dependent upon application. 

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Pump designs have largely been standardized. Based on appheation... 

Figure 3-36C illustrates the change in performance for the exact same pump, same impellers, but for different rotating speeds of 1750 and 3550 rpm. (Note that the respective motor designated standard speeds are 1800 and 3600 rpm, but the pump manufacturer cannot count on these speeds under load in order to provide performance information the customer needs for design of a system.)... 

Pump manufacturers have established guidelines to ensure each pump they supply is not exposed to conditions that result in cavitation. The design standard is called NPSHR or net positive suction head required. The NPSHR takes into account any potential head losses that might occur between the pump s suction nozzle and impeller thereby ensuring the liquid does not drop below its vapour pressure (bubble point). The NPSH is a measure of the proximity of a liquid to its vapour pressure, and must exceed the pump manufacturer s pump NPSHR. There are two process variables that can be adjusted, in case the available NPSH is less than the NPSHR raise the static head and lower friction losses. Conversely, the NPSHR can be reduced by using a larger, slower speed pump, a double suction impeller, a larger impeller inlet area, an oversized pump and a secondary impeller placed ahead of the primary impeller. 

A set of pumps in a pit recirculates the cooled water. Submerged vertical pumps are standard in this service. When using multiple pumps with large capacities, it is necessary to space them properly and to design the pit to allow unimpeded access of the water flow to the suction of the pumps. The requirements of the pump vendors will fix this aspect of design. Any reverse flow through idle pumps recycles to the basin and reduces the efficiency of the process. Check valves and anti-reverse mechanisms help to prevent this. 

Since extremely narrow resonance lines can be obtained in optical pumping experiments, frequency standards of comparatively simple design can be achieved. The hyperfine transitions used in the atomic-beam clock are also used in the optically pumped frequency standards. However, the resonance frequency is comparatively strongly dependent on the pressure of the buffer gas [7.18]. It is also dependent on the intensity of the pumping light ("light shifts") [7.16]. Thus, it would seem that an absolute frequency standard of maximal precision cannot be achieved. On the other hand, optically pumped systems have proven to be very suitable for relative measurements and as secondary standards. By observing sharp AF = 0, AMp = 1... 

AVS (American Voluntary Standard) pumps This standard, Issued by the Hydraulic lastltute, outlines. several pumps with. standard dimeasioas. They are interchangeable for a given size, regardless of wbt> builds the pump, with no effect on foundation, piping design, or type of electric motor ased. 

The hydraulic loads from the pump wet end are ultimately transmitted to the pump shaft and bearings. Because of the need to access all the pump parts for replacement due to wear during maintenance, slurry pumps have standardized cantilever designs, with all bearings well protected from solids ingestion. 

American Petroleum Institute (API) process pumps Designed to meet the 610 standard set by the API. 

Pump standard Pump designed according to American National Standard Institute Standards is an ANSI pump. Pump designed according to American Petroleum Institute Standard 610 is an API pump. 

At this time the only pumps considered capable of meeting these requirements are of the hermetically sealed canned-motor centrifugal type. They consist of a centrifugal pump of standard hydraulic design and an electric drive motor, built in an integral unit. 

Under current LWR design standards, bottom mounted inlet coolant pipes are not allowed from LOCA considerations. The inlet coolant compressors are necessary. These are larger in capacity and power consumption than feedwater pumps of LWRs, because of the low density of the high temperature supercritical steam. These factors finally led to a loss of interest in developing the water moderated, supercritical steam cooled reactor. 

To accommodate smaller liquid flows of about 10 pl/min, micro-ultrasonic nebulizers have been designed. Although basically similar in operation to standard ultrasonic nebulizers, in these micro varieties, the end of a very-small-diameter capillary, through which is pumped the sample solution, is in contact with the surface of the transducer. This arrangement produces a thin stream of solution that runs down and across the center of the face of the transducer. The stream of sample... 

Standard Chemical Pump. In 1961, the American National Standards Institute (ANSI) iatroduced a chemical pump standard (29), known as ANSI B73.1, that defined common pump envelope dimensions, connections for the auxiUary piping and gauges, seal chamber dimensions, parts mnout limits, and baseplate dimensions. This definition was to ensure the user of the availabiUty of iaterchangeable pumps produced by different manufacturers, as well as to provide plant designers with standard equipment. A typical ANSI chemical pump, known as of the mid-1990s as ASME B73.1M-1991, is shown ia Figure 6. 

The pump-mounting feet are located close to the centerline. As a result, the pump thermal growth is uniform on both sides of the centerline, leading to minimal distortions. The design is governed by the American Petroleum Institute (API) standard 610, "Centrifugal Pumps for General Refinery Service" (30). 

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