Spring- ■loaded, 375 Well

Both the variable and constant-effort springs as well as counterweights are provided with adequate movement range and means for load adjustment to allow for unusual line displacements. 

Rupture discs are specially designed to rupture at a specified relief set pressure. They usually consist of a calibrated sheet of metal designed to rupture at a well-specified pressure. They are used alone, in series, or in parallel to spring-loaded relief devices. They can be made from a variety of materials, including exotic corrosion-resistant materials. 

Others such as Macas et al. (1998) successfully adapted the Biomek 2000 (Beckman Coulter), a commonly used liquid handling robot, to prepare microarray slides using a specially constructed print head and quill pins. Up to 28 microscope slides could be placed on a work surface for printing. Biomek s HDRT head was adapted to accept microarray quill pins held between two parallel plates with holes drilled on 9-mm centers to dip into 96-well source plates. The quill pins were spring-loaded similar to the design... 

Safety relief valve (SRV ) Spring-loaded PRV that may be used as either a safety or a relief valve, depending on the application. The SRV works within well-determined operational limits (per PED it is called safety valve). 

This method works well for viscosities from 1 to 103 Pa-s. For somewhat higher viscosities, the torque on the spindle becomes excessive. For these viscosities, a crucible rotation speed is selected so that the spindle lag is near the maximum measurable value. The rotation is then stopped, and the spring loading of the spindle is then allowed to drive the spindle back to its rest point (zero torque). The elapsed time between two selected angles from the rest point is measured during the return. The viscosity is then measured from the following equation [4] ... 

In some cases, after careful evaluation, other valves may be considered for EBVs such as spring-loaded control valves that fail closed, back flow check valves (these are not normally considered reliable enough for EBVs by many engineers), and excess flow valves. Excess flow is the loss of material from the confined environment of a vessel or pipeline. Two approaches are available for the detection and valve action of excess flow valve systems (1) External, where excess flow is detected outside the valve itself, and (2) internal, which is within the valve unit and has limited applications. Excess flow conditions are detected more readily because of loss of resistance to flow than because of loss of pressure. All excess flow detection systems are based on product physical properties as well as flow rate. A change of products or process conditions may require a change in the excess flow detection system. For example, a number of excess flow valves are rated for low pressure and are made of materials not suitable for hydrocarbons. 

Both classical and modified types of biopsy needles are available suction needles (e. g. Menghini, Klatskin, and Jamshidi) and cutting needles (e. g. Vim-Silverman and Tru-cut) as well as spring-loaded needles. (12, 26, 86, 123, 129, 158, 162)... 

Pressure-relief devices include direct spring-loaded and pilot-operated relief valves that close or reseat if the vessel pressure is brought back into a safe condition, as well as non-reclosing devices such as rupture disks and breaking-pin devices. 

Design of spring-loaded pressure-relief valves is supported by a well-established mechanical engineering science base. With the use of established techniques, together with modern developments in zone and field modeling, there is potential for incremental improvements to be made to flow structure and stability or modulation of relief valves. However, for leading manufacturers supplying the mass market, the performance vs. cost balance must surely be close to its optimum. 

The sample wells in the gel plate are punched by means of a puncher. The puncher is usually constructed in such a way that it also removes the gel plug (its end is attached to a vacuum source and the plug is sucked off into a reservoir). The puncher is made of two annular steel tubes the outer with its sharp edge serves as a knife to cut the well, the inner tube is spring loaded, slides downwards when pressure is applied, and sucks the plug away. Slits in the outer tube release the vacuum in the inner tube. The wells are prepared by means of a template, which is composed of a base plate to which a sliding ruler is attached. The ruler is equipped with a series of holes with the same diameter as the outer diameter of the puncher. Punchers for different sample wells are available (2-4 mm). 

Internal combustion engines implementing the Otto cycle have been studied based on the rotary engine with a triangular rotor (Wankel), as well as free and spring loaded linear pistons. 

In the measurement of barrel temperature, a temperature sensor is pressed into a well in the extruder barrel the sensor is generally spring-loaded see Fig. 4.13. Most temperature sensors are constructed with a metallic sheath to obtain sufficient mechanical strength. As a result, significant thermal conduction errors can occur. 

---