Valve components

The PTFE micropowders are commonly used in plastics, inks, lubricants, and finishes such as lacquer. Lubricants containing micropowders are used for bearings, valve components, and other moving parts where sliding friction must be minimized or eliminated. Nonstick finishes that require good release properties, for example, in the food and packaging industry, commonly use PTFE micropowders. 

Uses. Apphcations of both these alloys iaclude pump and valve components and spray no22les. MP35N alloy is also popular for fasteners, cables, and marine hardware. 

Copper and brasses Heat exchanger tubing, bearings, valve components, gaskets, brewing equipment... 

Borkowski, R. J. et al., In-Plant Reliability Database for Nuclear Plant Components Interim Report - The Valve Component, ORNL, December 1983. 

Define the level of resolution. Will the analysis consider just a valve, or will it be necessary to consider the valve components ... 

Warehouses are normally considered low risk occupancies unless high value or critical components are stored. Some high valve components normally overlooked in warehouses are diamond (industrial grade) studded drill bits or critical process control computer boards. In these cases the economic benefits of installing an automatic sprinkler system should be investigated. 

Valve components, gaskets, tubing electrical insulation... 

Valve components Material or material standard Remarks... 

Comparison of partial stroke curves from past tests can indicate the gradual degradation of valve components. Use of overlay graphics, identification of unhealthy shifts in servodrive, increases in valve friction, and changes in dynamic response provide information leading to a diagnosis of needed maintenance. 

Ceramic materials, including sapphire, have been used extensively in HPLC pumps for more than 20 years as pistons and check valve components. These materials have also been used to construct heads because of their good chemical stability. The use of ceramics is limited, however, because of high cost and brittleness. Although many systems have one material as the primary construction material, the wetted surfaces of a pumping system can contain several other materials. Therefore, for material-sensitive applications, all the materials in the HPLC eluent flow path should be considered. Materials that may be encountered are polymeric materials for pump seals such as fluoropolymers, polypropylene, and Teflon sapphire pump pistons and check valve seats ruby check valve balls Kalrez, KelF, or ceramic washers and spacers polymer-based transducer components and in older systems connections and joints made with silver solder. 

Because of its excellent chemical resistance, ETFE is used in the chemical industry for valve components, packings, pump impellers, laboratory ware, and battery and instrument components and for oil well, down-hole cables 41 Examples of such applications are shown in Figures 4.17 and 4.18. 

Burel, S., Brouet, G., and Grandsire,T. (2004), Moisture uptake in pMDIs The effect on valve component materials, paper presented at Drug Delivery to the Lungs XV, London, pp. 297-300. 

Resistance. The pump should be inert to the various solvents, buffer salts and solutes to which it will be exposed in general use. In the vast majority of applications, stainless steel is used for metallic parts that contact the mobile phase, and this is perfectly acceptable. Elsewhere in the pump, resistant minerals such as sapphire or ruby are used for the pistons and in valve components subject to hard wear, and materials such as PTFE (Teflon ) are used for gaskets and seals. 

Provided there is always sufficient cosolvent present to preserve the true solution status of the product, no issues with drug deposition on the valve components and container. 

Ferrule An aluminum cup that holds the valve components together and attaches them to the can in the crimping process. 

At the other extreme are aerosols, where neither the product nor the pack can exist without the other. Aerosols can be used to dispense powders, liquids, sprays, gels, true aerosol clouds, etc., either as a continuous delivery or as a controlled or metered dose. The main container component can be fabricated from metal (aluminium or tinplate), glass or plastic coated glass, or plastic (e.g. polyester), and the valve components from combinations of plastic, metal and rubber. Depending on the product usage, the majority of the tests listed earlier may have to be involved in the clearance of an aerosol, particularly if it is a metered dose aerosol for administration of a product to the lungs (a critical administration route). 

Ceramics Carbon (pyrolytic carbon) Heart valve components Bioinert Dellsperger, and Chandran (1991)... 

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