Stainless steels standard numbers

The method will now be tested in a ringtest by 8 dfferent laboratories in Europe. A preliminary range finding will be done in Vienna in October 1999. Test oganisms will be Stapylococus aureus and Pseudomonas aeruginosa, exposure time will be 5 minutes. The test surfaces will be stainless steel disks (2 cm diameter) with a specific finish. The problem of a standardized drying procedure was discussed. There was no decision about the number of replicates of the test. 

Numbers result from common computer analyses and not all such figures will be necessarily significant PCS = Plastic-coated steel hydrowire SS = Stainless steel (type 302 unlubricated) hydrowire KEV = Kevlar hydrowire HB = Hydro-bios sampler MGF = Modified GO-FLO sampler Mod GF = Unmodified GO-FLO sampler Exw GF = Unmodified GO-FLO sampler NIS = Modified Niskin sampler m = mean sd = standard deviation... 

The required heat-transfer area of 19.5 m2 is based on an overall heat-transfer coefficient of 102 W/(m2 K). The best exchanger geometry for this application includes six internal baffles, one shell-side pass and two tube-side passes. The shell is fabricated from standard carbon steel piping of nominal pipe size 30, schedule number 80. The 112 tubes required are each 1.83 m long and 38.1 mm (1.5 in.) o.d. (BWG 12). The tubes must be fabricated from stainless steel type 250 for reasons of temperature tolerance. 

The shell is constructed from carbon steel and will be fabricated from standard pipe of nominal size 30, schedule number 80. The 112 tubes required are 1.83 m (6ft) lengths and standard BWG 12. The tubes are made from stainless steel type 250 as recommended in the Australian Design Code AS1548 Design of Boilers and Pressure Vessels. 

Due to its ability to withstand high pressure, its relative low cost, and inertness, stainless steel has become the standard material of columns and other chromatographic components. However, under certain circumstances, stainless steel has been shown to interact with the sample and the mobile phase [39]. The best known example is chloride salt corrosion of stainless steel. Data indicate that nearly all common eluents dissolve iron from stainless steel [39]. It appears that proteins also adsorb to stainless steel [39], The adsorption process is fast, whereas desorption is slow, a result which leads to variable protein recoveries. A number of manufacturers are offering alternatives to stainless components with Teflon -lined columns and Teflon frits. Titanium is being explored as an alternative to stainless steel. A cheaper and simpler procedure is to oxidize the surface of the stainless steel with 6N nitric acid. This procedure should be repeated about every 6 months. 

Bar-code label (with also alphanumeric readout) Adhesive label, 8 mm x 20 mm (approximately) Sample preparation form, carbonless, duphcate Chpboard for sample preparation form Laboratory notebook Pen, permanent, archive approved Marker, permanent Pair of scissors Forceps, stainless steel Sealing film Spatula, stainless steel, spoon type Absorbent wipe, standard Laboratory coat Gloves, latex Gloves, durable, chemically resistant Disposable items (continued) Waste bottle, wide mouth, volume 2 liters with chemical resistant lid Waste bottle, wide mouth, volume 4 liters with chemical resistant lid Wash bottle, polyethylene, 250 ml 1 pack 1 pack 1 set 1 1 2 4 1 5 1 pack 12 4 2 boxes 2 coats 2 boxes 1 pack 1 pack Minimum number 1 1 2... 

Chromatographic System (See Chromatography, Appendix BA.) Use a gas chromatograph equipped with a flame-ionization detector and containing a 1.8-m x 2-mm (id) stainless-steel column, or equivalent, packed with 10% silicone GE XE-60, or equivalent. Maintain the column isothermally at a temperature between 175° and 185°, and use helium as the carrier gas at a flow rate of 30 mL/min. Chromatograph a sufficient number of injections of the Standard Preparation,... 

Chromatographic System Use a suitable gas chromatograph that is equipped with independent dual flame-ionization detectors and contains a 0.6-m x 6.35-mm (od) stainless-steel U-tube packed with Porapak P or equivalent. Use helium as the carrier gas at a flow rate of 60 mL/min, hydrogen as the fuel gas at a flow rate of 52 mL/min for each flame, and air as the scavenger gas for both flames at a flow rate of 500 mL/min. To ensure that the relative standard deviation does not exceed 2.0%, chromatograph a sufficient number of replicates of each Standard Preparation, and record the areas as directed under Procedure (see Chromatography, Appendix IIA). 

Storage tanks for finished fats and oils are preferably constructed of carbon steel, stainless steel, or aluminum. Finished-oil storage tanks vary considerably in size. Typically, they are designed to hold a given number of standard rail tank carloads of oil or a full operation batch of a deodorization vessel. A tank holding 500 metric tons of product is considered large, and a 10-metric-ton tank is considered small. 

This family of stainless accounts for the widest usage of all the stainless steels. These materials are nonmagnetic, have face-centered cubic structures, and possess mechanical properties similar to the mild steels, but with better formability. The AISI designation system identified the most common of these alloys with numbers beginning with 300 and resulted in the term 300 series stainless. Table 3 lists the chemical analyses of some standard austenitic stainless steels and compares them to a few materials from other families of materials. 

The analysis of separated volatile fraction can be carried out using a number of gas chromatographic columns and conditions including those described in the Standard Test Method ANSI/ASTM D 2267-68 (3). The following conditions were used by us in the laboratory studies GC column, 6% OV 101 on 100-120 mesh Chromosorb G-HP, 5 ft X i in-stainless steel column temperature, 1.5 min hold at 60°C, temperature programmed to 105 °C at 10°C/min detector, hydrogen flame ionization. 

Several fully automated spray-on sample applicators are available. In one device, a motor driven syringe is used to suck up sample volumes of 0.1 to 50 p.1, which are then deposited as spots or bands on the layer [104]. The syringe feeds a stainless-steel capillary connected to a capillary atomizer. The applicator can be programmed to select samples from a rack of vials and deposit fixed volumes of the sample, at a controlled rate, to selected positions on the layer. The applicator automatically rinses itself between applications and can spot or band a whole plate with different samples and standards without operator intervention. A number of multi-sample applicators for the simultaneous transfer and deposition of several samples at the same time have been described [106-108]. 

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