Thread plug

The second most commonly used header is a cover-plate header. The cover plate is bolted to the top, bottom, and end plates of the header. Removing the cover plate provides direct access to the tubes without the necessity of removing individual threaded plugs. 

A simple manifold is illustrated in Figure 40.41. This manifold contains one pressure inlet port and several pressure outlet ports that can be blocked off with threaded plugs. This type of manifold can be adapted to systems containing various numbers of subsystems. A thermal relief valve may be incorporated in this manifold. In this case, the port labeled T is connected to the return line to provide a passage for the relieved fluid to flow to the reservoir. 

Prevention of access is the least intrusive method since it need not have any irreversible consequences for the afferent pathway. The common entrance to both olfactory systems in newts is easily closed-off by plugging the nostrils (Kikuyama et al., 1997). A potentially reversible method threaded plugs into the NP canal of cats via the nasal cavity (Verbeme, 1980). This procedure produced a slight effect on male chemoinvestigation of urine and or scent marks. The advantages of avoiding tissue disturbance then, have to be offset by the lack of any estimate of the effectiveness of the blockade, especially if reversible. Tissue cement injections into the N-Pd can be applied to the larger... 

The protection philosophy seems to be to protect the cylinder from overpressure by protecting it from over-temperature that would vaporize the liquid chlorine. Each of the fusible plugs is in a 3/4-inch threaded plug. If the fuse melts, the resulting hole is about 11/32 inch in diameter. 

When not in use, the cannula is sealed from the exterior by inserting a threaded plug which allows pancreatic juice to enter the duodenum in the normal manner (Fig. 2, part C). For collection of juice this plug is removed and a long obturator is inserted (Fig. 2, part D). The latter effectively isolates the pancreatic secretion from other duodenal contents. 

The basic heat-transfer surface is a bank of 1 to 20 (but usually 3 to 12) rows of high-tinned tubes. The fluids enter the tubes by box headers (pipe headers at higher pressures), with the tubes welded into one wall of the header internal dividers are used in the headers to create multiple tube passes. The header cover may be bolted to the header, or the header may be welded, with threaded plugs opposite the tube ends to facilitate assembly and tube cleaning. The tubes are slanted downward toward the exit (about 1/4 in. per ft) to facilitate drainage. Occasionally, especially for turbine steam condensation, an A-frame configuration is employed, with the tubes slanted about 30° from the vertical and the fans mounted in forced draft at the base of the A, thereby reducing the plan area required. 

Typical stress conditions may be created by capping (tension between bottle and cap threads), plugging (expansion of the neck bore), top pressure occurring during stacking, etc. 

Clean out- An opening providing access to a drain line. Closed with a threaded plug. 

A spring returns the plunger to its normal position. A threaded plug is provided in the top of the shock absorber to permit access to the rod locking device. 

A hollowed threaded plug having the hollowed portion filled with a low-melting-point material. This element is often used to provide a mechanical relief device triggered by temperature causing the process fluid to vent when the plug material melts. It is typically used in a pneumatic fire detection system or sprinkler system to indicate the presence of a fire condition and disperse the gas or fluid in the contained system. 

Figure 8-14. Bridgman type closures (A) Threaded plug type (B) Floating head type for large diameter heads (C) Modified type using rings to prevent extrusion of the gasket (D) Studded outlet with floating head.

Apart from being easier to use than conventional mastics, anaerobics offer a major benefit for sealing potable water pipes in that they are inert and do not support microbiological activity. They will successfully seal both plain and threaded plugs with both speed and economy. 

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