Small-bore

S. K. Combs and co-workers, Pepetitive Small Bore, Two Stage Eight Gas Gun, CONP-9110244-1, Oak Ridge National Lab, Term., 1991. 

Autofrettage of small bore tubes can be effected by pushing highly poHshed and generously lubricated oversized drifts or balls through the bore. 

Short-term (100 h) internal pressure creep mpture testsof small bore cylinders having diameter ratios of 3 to 4, made of a number of different refractory metals, have been investigated at temperatures in the range 900—1300°C (73). 

Many initiators attack steels of the AISI 4300 series and the barrels of the intensifiers, which are usually of compound constmction to resist fatigue, have an inner liner of AISI 410 or austenitic stainless steel. The associated small bore pipework and fittings used to transfer the initiator to the sparger are usually made of cold worked austenitic stainless steel. The required pumping capacity varies considerably from one process to another, but an initiator flow rate 0.5 L / min is more than sufficient to supply a single injection point in a reactor nominally rated for 40 t/d of polyethylene. 

To use the port, the overlying skin is prepared using conventional techniques. A local anesthetic is sometimes used to decrease pain of needle insertion, though this is usually not necessary using techniques which utilize small-bore needles. A special point needle is used to puncture the implanted ports as the point of these needles is deflected so it tears the septum rather than coring it, allowing multiple entries. The septum reseals when the needle is removed. 

The main interest in polybut-1 -ene is in its use as a piping material, where the ability to use a lower wall thickness for a given pressure requirement than necessary with other polyolefins, together with the low density, can lead in some cases to economic use. The principal application is for small-bore cold and hot water piping (up to 95°C) for domestic plumbing. Current world-wide sales are of the order of 16-20X10 tonnes per annum. 

There are two types of sample valve commonly used in LC, the internal loop valve and the external loop valve. In order to improve the seating and eliminate leaks, the valve faces are sometimes made from appropriate ceramics. The internal loop valves are largely used with small bore columns, that is to say columns having internal diameters of less than 1.5 mm. The external loop valves are used for larger diameter columns up to semi-preparative columns. 

The column is a small bore column and, thus, the eluted peaks have a relatively small peak volume, which is commensurate with that of the sensing cell. It is seen that even a sensor volume of 1 pi has a significant effect on the peak width and it is clear that if... 

They are not recommended for dirty or fouling services, because of plugging of the pilot valve and small-bore pressure-sensing lines. If the pilot valve or pilot cormections become fouled, the valve will automatically open. In special cases where fouling is a function of entrained solids, this limitation may be countered by the use of a nonflowing pilot valve and a pilot line filter. With a nonflowing pilot valve, there is no normal flow in the pilot system and therefore solids entrainment is reduced. 

How should we clear chokes in small bore lines ... 

Pipes, particularly small-bore pipes, often have failed by fatigue because their support was insufficient and tlie pipes were free to vibrate. On other occasions, pipes failed because their support was too rigid and tliey were not fi ee to expand. Supports for pipes usually are constructed on site, and often it is not apparent until start-up tliat tlie supports are inadequate. Even at tliis point, tlie necessary reinforcement may not be done because it is not considered a priority at start-up. 

The highest possible degree of hemocompatibility is essential for certain applications, including small-bore artificial prostheses. 

It is not proposed to deal with forced convection here. Experimental work has yielded considerably differing results for ostensibly similar conditions. It is sufficient to note that forced convection affects small-bore pipes to a greater extent than large-bore and is dependent on temperature differences. While the heat loss from non-insulated surfaces may increase by a factor of up to 200-300 per cent, the increase in heat loss from the insulated surface would be considerably less (of the order of 10 per cent). 

In a watertube boiler, water circulates through small-bore tubes constructed in banks and connected to drums or headers. The external surfaces of the tubes are exposed to the products of combustion or hot gases. 

The present vertical boiler is generally used for heat recovery from exhaust gases from power generation or marine applications. The gases pass through small-bore... 

The current spread from an internally immersed anode is directly related to pipe size and the resistivity and temperature of the water with sea-water having a resistivity of about 30Qcm, anodes are normally required on a 10 in (250 mm) pipe at about 1 m centres and in the case of a 30 in (760 mm) pipe, at 3 m (10 ft) centres (Fig. 10.32). Small bore or high resistivities and velocities further reduce the anode spacing. 

Water and brine pumps may be isolated with flexible connectors. For small-bore pipes, these can be ordinary reinforced rubber hose, suitably fastened at each end. For larger pipes, corrugated or bellows connectors of various types can be obtained. In all cases, the main pipe must be securely fixed close to the connector, so that the latter absorbs all the vibration. Flexible connectors for the refrigerant usually take the form of corrugated metal hose, wrapped and braided. They should be placed as close to the compressor as possible. 

SODIUM When NaCl is administered by IV infusion, the nurse observes the patient during and after administration for signs of hypernatremia (see Display 58-2). The nurse checks the rate of IV infusion as ordered by the primary health care provider, usually every 15 to 30 minutes. More frequent monitoring of the infusion rate may be necessary when the patient is restless or confused. To minimize venous irritation during administration of sodium or any electrolyte solution, the nurse uses a small bore needle placed well within the lumen of a large vein. 

The separation was carried out on a small bore column 25 cm long and 1 mm i.d. packed with silica gel having a particle diameter of lOp. The mobile phase was n-hexane saturated with water and the flow rate 50 pi per min. 

Small Bore Liquid Chromatography Columns", (Ed. R.P.W.Scott), John Wiley and Sons, New York-Chichester-Brisbane-Toronto-Singapore, (1984)23. 

It is seen that with 1 ml samples the peak for a concentration of 1 ppm is well off scale and a clearly defined peak was observed for 10 ppb. When a 10 ml sample was used, acetophenone at a concentration of 1 ppb could just be detected. Under the conditions used, the ultimate mass sensitivity of the system was about 10 ng. This level of sensitivity was achieved, on the one hand, by the sample concentrating process, and on the other, as a result of the high mass sensitivity of small bore columns. 

It is seen that there are a large number of compounds capable of dispersive interactions with the reverse phase, contained in the serum that have been extracted and separated. Again the results have been obtained, partly as a result of the extraction and concentration properties of the sampling system, and partly as a result of the high mass sensitivity of the small bore columns. 

Small Bore Liquid Chromatography Columns Their Properties and Uses. Edited by Raymond P. W. Scott... 

Images of spray and combustion in the rapid compression machine obtained for conditions representative of typical HSCI-engine operation. The sequence of four images covers the period immediately after injection—far left, and until the full development of a reacting jet—far right. (From Lu, P.-H., Han, J.-S., Lai, M.-C., Henein, N., and Bryzik, W., Combustion Visualization of DI Diesel Spray Combustion inside a Small-Bore Cylinder under Different EGR and Swirl Ratios, SAE, 2001-01-2005, 2001. With permission.)... 

A very convenient way of closing the ends of glass tubes for blowing, particularly with very small bore tubing into which it is difficult to fit... 

Working capillary tubing requires a slightly different technique from the working of normal tubing. This is principally due to the small bore of the tube and the very thick walls. Generally speaking it is necessary to use a smaller, hotter flame for capillary than would be... 

The finished bead, shown in Figure 36, III, will, when made correctly, be coloured something between a straw yellow and a reddish tan. If desired, the bead may be enlarged at one end or in the middle to assist in fusing it into a small bore tube as indicated in Figure 36,... 

An assortment of small corks for closing small bore tubing can, in addition, be very useful. If the flame is to come near to a cork or a rubber stopper it is best to wrap either in thin asbestos paper before inserting into the tube. When pyrolysis of the cork or rubber stopper seems probable it is best to use a cork and not a rubber stopper, because the pyrolysis products from a cork can be cleaned olf more easily than those from rubber. Sometimes a plug made from damp asbestos paper is adequate for closing a tube of small bore, and this plug can be heated quite strongly. 

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