Bypass filters

The lube oil pumps are now ready to be turned on. The pump and filter bypass valves should be open to avoid pressure pulses in the filter eartridges. Strong pressure pulses may eause filter eartridges to eollapse. Typieal filter elements will withstand 35-100 psi differential. If the pumps are turned on with eaeh bypass elosed, an instantaneous pressure of approximately 150 psi will hit the filters. This is due to the setting of the relief valves. For this reason, it is important to have on hand several extra seal gas and lube oil eartridges. 

After the lube oil pumps have been running for approximaely 15 min, elose the pump and filter bypass and slowly pressurize the system to establish normal lube oil pressure. The alarm and shutdown lights should turn off by pushing the reset button on the annuneiator panel. 

Improper filtration plugged filters bypassing of filters... 

Figure 4 shows the radon produced with the filter bypassed and Figure 5 shows the radon in air and water use with the data analyzed for average radon before and after filtration by averaging the radon in air. The average value for filter bypassed is 2.39 pCi/1 for days 1 and 2, and 2.67 pCi/1 for days 5, 6, and 7. The radon in air for the days with the filter connected (days 8, 9, 10) is 1.00 pCi/1. 

Pressure differential gauges and filter bypass alarm. 

Filter Bypass Valve—For Models 202, 203, and 215—check for leakage at least once a year (see Appendix X5). 

XI. 5.6 If the time measured to reach 100 mm AP exceeds 60 s, either the filter bypass valve is leaking or the fuel metering pump performance is unsatisfactory. In this case, the fuel metering pump performance should be checked to determine if the pump or filter bypass valve needs to be replaced. 

The provision of filter bypass doors is a mixed blessing. These doors are notoriously difficult to seal, and are a potential area where all the money spent on a good filter system can be wasted. They are designed, of coxmse, to help maintain production and are, at times, hazardous to the health of the turbine. A typical... 

Rapid compressor fouling was usually the prelude to more serious problems later, since it was usually caused by the combined problems of filter bypass. 

Filters separate and retain the dirt from the oil. They are rated based on the size of the largest particle that can pass through, Vlost machines in petrochemical plants use lO-rnicron filters. Alarms are provided to signal when a filter becomes clogged up with dirt, A v aking system allovvvs the oil to be bypassed to an alternate filter, while the element of the first one is replaced. Filter elements can be... 

These oscillations can be dampened with the use of filter circuits or by bypassing all or part of the series compensation dtiring a line disltirbtmce. Similar techniques arc adopictl while protecting... 

At high pressure experiments the reactor should be installed in a pressure cell. All check valves before it, and the filter with the flow controller after it, can be kept in the vented operating room. As a minimum, the bypass valve and the flow controller must be accessible to the operator. This can be done by extended valve stems that reach through the protecting wall. Both the operating room and the pressure cell should be well ventilated and equipped by CO alarm instruments. 

The gas quality feeding the dry faee seal should be elean and dry. Due to the possibility of eondensation of the proeess gas in the seal eavity, it was deeided to use a seal gas heater. The heater eontrol was set to provide warm gas at 15°C above the dew point to ensure no eondensate entered the seal eavity. Also, a dual filter in series with 5 and 2 p filtration elements was ehosen to provide an ideal sealing environment and maintain the optimum performanee of the seal. To reduee the risk of seal damage during reverse rotation of the turboexpander, programming logie was set to open the eompressor bypass valve whenever a shutdown impulse was initiated. 

The filter elements should be replaceable and should be corrosion resistant. The filter should not contain any type of internal relief valve that would permit the bypassing of the dirty oil. 

Answer Use the plant s PSA to determine the risk of accidents that include containment failure from overpressurization. Then make a preliminary design of a vented containment that has sufficiently low impedance to the gas at the pressure predicted for the most severe accident sequences such that the containment is not damaged. This containment bypass will include iodine and HEPA filters as well as scrubbers and a discharge through a stack. Estimate the dose that the population would get using this bypass for comparison with the PSA result for ruptured containment sequences. 

The e. posure route partly determines the distribution of the chemical in die body. Like tlie chemical benzene, a single chemical may follow multiple routes of e. posure. The liver, like the skin, acts as a filter. The liver is the primary dcto.xification site. To.xicants that arc absorbed into the lungs, skin, mouth, and esophagus may temporarily bypass the liver however, toxicants absorbed tluougli the stomach and intestines follow the blood s direct path to tlie liver. 

Simple strainers remove gross materials. These should not normally occur in public supply, but strainers are sometimes fitted to protect sensitive equipment or processes against breaks in the main, etc. The commonest form contains a stainless-steel wedge wire screen and is piped with a bypass so that the screen element can be isolated and removed for cleaning when necessary. If the load on the filter makes this kind of cleaning burdensome a self-flushing filter can be used. These can incorporate strainer elements down to 50 pm. 

It is impossible to generalize about types of filter to be used. Selection depends on the system, the rate of contamination build-up and the space available. However, a common arrangement is to have a full-flow filter unit before the pump with a bypass filter at some other convenient part of the system. Many industrial systems working below 2000psi can tolerate particles in the order of 25-50 microns with no serious effects on either valves or pumps. 

The core - flood apparatus is illustrated in Figure 1. The system consists of two positive displacement pumps with their respective metering controls which are connected through 1/8 inch stainless steel tubing to a cross joint and subsequently to the inlet end of a coreholder 35 cm. long and 4 cm. in diameter. Online filters of 7 im size were used to filter the polymer and brine solutions. A bypass line was used to inject a slug of surfactant solution. Two Validyne pressure transducers with appropriate capacity diaphragms are connected to the system. One of these measured differential pressure between the two pressure taps located about one centimeter from either end of the coreholder, and the other recorded the total pressure drop across the core and was directly connected to the inlet line. A two - channel linear strip chart recorder provided a continuous trace of the pressures. An automatic fraction collector was used to collect the effluent fluids. 

In the solvent-refined coal pilot plant at Wilsonville, Alabama, the coal slurry is heated to reaction temperature in 3-4 minutes residence time in the preheater. The slurry is then held in the dissolver for an additional 40 minutes before it is filtered to obtain specification solvent-refined coal. By bypassing the dissolver and going directly to the filters, samples of short-contact time (SCT) SRC were produced from Illinois 6 (Monterey) and West Kentucky coals. 

Now, where could the problem lie Is it within the power supply stage itself, or is it external If you have peeled the onion as I suggested previously, you are hopefully sure the efficiency is not being lost within the EMI filter of your AC-DC power supply. Bypass or disconnect everything external and confirm you have a problem. 

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