Slip joints

Interna] Insulation The practice of insulating within the vessel (as opposed to applying insulating materials on the equipment exterior) is accomplished by the use of fiber blankets and hghtweight aggregates in ceramic cements. Such construction frequently incorporates a thin, high-alloy shroud (with slip joints to allow for thermal expansion) to protect the ceramic from erosion. In many cases this design is more economical than externally insulated equipment because it allows use of less expensive lower-alloy structural materials. 

The methods of construction usually encountered are (a) lock-formed, (b) welded, (c) slip jointed and (d) flanged. 

In KBR closed cyclone technology, each set of riser and upper reactor cyclones is connected via the use of a slip joint conduit. The stripper steam and hydrocarbons, as well as dome steam, exit the reactor housing by entering through this conduit as shown in Figure 9-5. 

If unbalanced layouts cannot be avoided, appropriate analytical methods must be apphed to assure adequate flexibility. If the designer determines that a piping system does not have adequate inherent flexibility, additional flexibility may be provided by adding bends, loops, offsets, swivel joints, corrugated pipe, expansion joints of the bellows or slip-joint type, or other devices. Suitable anchoring must be provided. 

Pressure thrust, which is the product of the effective thrust area times the maximum pressure to which the joint will be subjected during normal operation. (For slip joints the effective thrust area shall be computed by using the outside diameter of the pipe. For corrugated, omega, or disk-type joints, the effective thrust area shall be that area recommended by the joint manufacturer. If this information is unobtainable, the effective area shall be computed by using the maximum inside diameter of the expansion-joint bellows.)... 

Thermal expansion and the resultant pipe stresses must be considered in any piping system design. For example, if the temperature changes from 50 to 600°F, the increase in length would be 4.9 in. per 100 ft for steel pipe and 7.3 in. per 100 ft for brass pipe. This amount of thermal expansion could easily cause a pipe or wall to buckle if the pipe were fastened firmly at each end with no allowances for expansion. The necessary flexibility for the piping system can be provided by the use of expansion loops, changes in direction, bellows joints, slip joints, and other devices. 

Figure U-3 shows a liquid-sealed stirrer and gas-delivery tube (b) provided with a glass rod slipped through a section of suction tubing should the delivery tube become plugged, it can be freed with the glass rod. The stirrer sleeve (u) is extended well into the flask so that the liquid itself seals the stirrer. A simple rubber slip joint can also be used a stirrer sleeve similar to (a) but extending only a short distance into the flask is provided with a 2-cm. section of rubber tubing which projects above the end of the tube and fits snugly around the stirrer shaft. The point of contact between rubber and shaft is lubricated with glycerol.

Through the central neck of a 500-ml. three-necked round-bottomed flask provided with ground-glass joints is passed a mechanical stirrer provided with a simple rubber slip joint (glycerol-lubricated). The side necks are provided with one-hole rubber stoppers, through which... 

The slip-type joint (Figure 7-112) is particularly useful in steam and hot-water transmission lines where expansions and contractions are frequent and of large magnitude. Slip joints contain no highly-stressed flexing element subject to failure after a finite number of cycles. 

A slip joint fitted with a sliding member at only one end is known as a single-end joint. When sliding members are used at both ends, the joint can absorb twice the expansion of a single-end joint and is known as a double-end joint. 

Figure 7-116. Typical refinery Diping system using slip joints to absorb the expansion and contraction.

Nominal Pipe Size Slip-Joints Convoluted Expansion Joints ... 

Operator-based maintenance began with the entrepreneurial spirit of the cottage industry in the U.S. free enterprise system. In most cases, the owners fixed the sawmills, the cotton gins, the printing presses, and the wagon wheels. Owners were the skilled crafts people working within a free enterprise culture and system. For many Americans, OEM started with Henry Ford s Model T, which came with tools—a crescent wrench, slip-joint pliers, screwdriver, and hammer, and so on—for the do-it-yourself repairs. 

Machine screws (or bolts) require special tools. The combination wrench is one type of hand tool used with machine screws. The adjustable wrench is more versatile, allowing the technician to use it with different sizes of machine screws (see Figure 8-20). We may also use pliers, second-class levers, during the combining process. Pliers can be found in various types (see Figure 8-21). Slip joint pliers allow material to be held firmly. Needle nose pliers can hold smaller items. Diagonal pliers (cutters) are actually a shearing tool for wire. 

To eliminate slip, jointing should be by combined bolting and bonding. 

Gleitstromung, Schltlpfstromung, viskose Stromung slip-joint connection Gleitverbindung slip plane (crystal slip)... 

Cracking of internal core spray piping has been observed at numerous BWRs [5.18]. Cracking has been found in the thermal sleeve collar, the downcomer slip joint sleeve (a creviced weld), and the downcomer piping elbow weld. Accessibility for inspection of creviced locations is extremely limited. 

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