Duplex filters

Increase Bottoms traffic Inject a continuous Cycle Oil flush into inlet Bottoms PA Exchangers Install duplex filters upstream of Bottoms Pumps... 

Add A single transfer valve for the duplex filters is requited... 

Duplex filters are designed for use where an uninterrupted fuel flow is required, or where an immediate standby filter is essential. Fuel oil filters can generally incorporate air vents, drains and tappings for pressure differential instruments. Steam jackets, magnetic elements and interlocking safety devices may also be fitted. Fuel oil cartridges for this type of filter are fitted with media capable of operating up to 160°C, with a 4 am nominal filtration efficiency, and can withstand a 10 bar pressure differential. 

In most cases, the PRVs must be protected fi om liquid slugs, which could be present in the gas supply fine. A vertical gas separator is the primary choice to remove both liquid slugs and mist. Duplex filters or filter separators are located... 

Duplex, switehable filters are eonsidered standard. A eontinuous-flow switehing valve and 10 p filtration elements should be provided. 

Reliable enclosed filters of ample effective filtering area should be used for both stages. The filter design should not allow the pressure drop to exceed 7kN/m (1 Ibf/in ) across second-stage fine filters in clean conditions. Filters should preferably be of the duplex or self-cleaning type, and installed so that oil spillage will not occur during operation. 

Alternative 2 consists of preliminary treatment followed by dual-media pressure filtration, and two-stage air stripping (Figure 8.4). The preliminary treatment step for iron removal would be exactly the same as specified under Alternative 1. The filters would be recommended to remove suspended matter and particulate iron prior to the air strippers. The required filtration capacity could be provided with either a duplex system of two 60-in.-diameter filters or a triplex system of three 42-in-diameter filters. 

Following incubation, add an equal volume of 10% TCA to the reaction mixture. Mix and cool to about 5° for 1 hr. Collect the precipitates, which are the SI-resistant duplexed DNA fragments, on nitrocellulose filters, dry, and count for radioactivity. 

An estimate of the extent of base-pair mismatch between hybridized DNA strands can be made by measuring the thermal stability of the reassociated duplexes. Place hybridized filters in fresh incubation buffer and heat at 5° increments to 90°. At each 5° increase, remove a small sample of the buffer and count. Controls are reassociated homologous DNAs. The amount of nucleotide mispairing has been estimated at 1% for each degree the Tm of the heterologous duplex is lowered (Arm).2 31... 

Addition of Mg to these complexes leads to their dissociation. However, addition of alkali leads to the appearance of cleaved DNA molecules having protein covalently attached to the DNA (see below). This enzyme also forms complexes with relaxed duplex DNA but these complexes are not dissociated by the addition of Mg and cleavage of the DNA is not found when alkali is added (Liu and Wang, 1979). Complexes between procaryotic topoisomerase I and DNA can also be detected by their retention on nitrocellulose filters. Using this method the preferential binding of the enzyme to an internal single-strand break in a linear duplex DNA has been shown (Dean et al., 1982 Dean and Cozzarelli, 1985). 

In addition to the detection of antigens and antibodies, EIA will, undoubtedly, play an increasingly important role in molecular biology. For example, the bio-blot method (Leary et al., 1983) for the detection of DNA-DNA or DNA-RNA duplexes on nitrocellulose membranes offers important advantages over conventional procedures in which radioactive probes are used and autoradiographic detection. In this method, biotinylated DNA probes are prepared by nick translation (Rigby et al., 1977) in the presence of biotinylated analogs and hybridized with the DNA or RNA on filters. Biotin is then detected by avidin-labeled enzyme (Section 3.1). 

Windsor. Berks SL4 IRD Tel +44(0)1628 440906 Fax +44 (0) 1628 475667 Email info oxfordfiltration.com Web wAW.oxfordfiltration.com Manufacturer and Supplier of Simplex. Duplex Strainers and Self Clean filters for virtually any fluid duty... 

A duplex system uses two filter housings so that one filter is constantly on-line. When the pressure drop becomes excessive, and the filter requires changing, the flow is... 

If laboratory tests using a disc of the filter membrane indicate that the filter will have insufficient throughput or life then prefiltration ould be considered. Ideally both filters should come to the end of their service life together, i.e. the dirt holding capacity of both filters should be exhausted at the same time. This enables both filters to be replaced together. A duplex system switching over both prefilter and fine filter is available. 

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