Clamp Valves

FIGURE 10.2 Tubing diagram for Symbiosis system (LCV = left clamp valve DV-1 = divert valve DV-2 = divert valve 2 RCV = right clamp valve). (Source Adapted from Kuklenyik, Z. et al., Anal Chem 2005, 77, 6085. With permission.)... 

A PTFE clamp valve (Fig. 8.36) with full-flow, straight-through packless valve, is capable of bubble-tight shutoff and fine throttling. These features, coupled with minimum maintenance and corrosion resistance, makes the PTFE clamp valve an economical valve available for demanding chemical processing installations. 

The clamp valve consists of a flexible PTFE tube and a clamp. It is somewhat similar to a pinch valve, but, unlike a pinch valve, the tubing is not kinked, creased, or pinched. 

PTFE clamp valves are available in sizes 1" (2.5 cm) through 8" (20 cm) in various configurations and with a number of optional accessories. 

Because all wetted surfaces are PTFE, the clamp valves offer unsurpassed chemical resistance at temperatures up to 400°F (205°C) for 6" (15 cm) and 8" (20 cm) valves. 

Figure 8.36 Clamp valve. [Courtesy (a) Crane Resistoflex Co., and (b) Xomox Co.]...

Uses. Uses for copper—siUcon alloys are siUcon bronze, UNS C 87200, as bearings, pumps, valve parts, marine fittings, and corrosion-resistant castings siUcon brass UNS C 87400 as bearings, gears, impellers, valve stems, and clamps and siUcon brass UNS C 87500 as small propellers, valve stems, gears, and bearings. 

Rupture Disks A rupture disk is a device designed to function by the bursting of a pressure-retaining disk (Fig. 26-15). This assembly consists of a thin, circular membrane usually made of metal, plastic, or graphite that is firmly clamped in a disk holder. When the process reaches the bursting pressure of the disk, the disk ruptures and releases the pressure. Rupture disks can be installed alone or in combination with other types of devices. Once blown, rupture disks do not reseat thus, the entire contents of the upstream process equipment will be vented. Rupture disks are commonly used in series (upstream) with a relief valve to prevent corrosive fluids from contacting the metal parts of the valve. In addition, this combination is a reclosing system. 

The thermostatic expansion valve can also be used to maintain a liquid level. The phial and a heater element are both clamped to a bulb at the required liquid level. Illiquid is not present, the heater warms the phial to a superheat condition and the valve opens to admit more liquid. 

Nozzles Shutoff Valves Gas injection Equipment Qukkmold-Clamping Systems... 

The application of a clamp on a SV spindle to keep the valve in a fully-closed position, especially during a hydrostatic test. 

Polyacetals and other engineering plastics cost about half that of cast metals, and are therefore used as replacements for cast metal-intense applications. They have been approved by the Food and Drug Administration for contact with foods. Some of the uses of molded polyacetals are as valves, faucets, bearings, appliance parts, springs, automotive window brackets, hose clamps, hinges, video cassettes, tea kettles, chains, flush toilet float arms, gears, shower heads, pipe fittings, pasta machines, desktop staplers, and air gun parts. 

Remove filtration unit from autoclave pack, replace vent valve loosely, and mount on a clamp with the vent at the top. 

Bunsen, Robert W. von( 1811-1899). A Ger chemist noted for gasometric and photometric researches and for various inventions, such as burner, valve, cell, clamp funnel eudiometer. The first theory of the burning process of black powder was estabilished by him and simultaneously by a Russian chemist, L. Shishkoff. Bunsen lost the sight of his right eye due to the expln of cacodyl Cyanide, which he discovered together with other derivs of cacodyi... 

Figure 55. Nitroglycerin Buggy. (Courtesy Hercules Powder Company.) For transporting nitroglycerin from the storage house to the house where it is mixed with the other ingredients of dynamite. Note the absence of valves and the use of wooden hose clamps as a safety precaution.

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