Sliding joints

If a sliding joint is specified, the design specification should also include the following notes ... 

Type S is a floating head type. As the tubes heat up, they expand. As they expand, the floating head moves back and forth, but the pressure seal is not at the sliding joint. The pressure seal is at the fixed shell Joint in the outer head, which contains the pressure. The floating head floats free inside the pressure vessel as the tubes move. Types P and W are floating heads where the movement of the head effects the seal between either the shell-side or tube-side fluid and atmosphere. 

A simple bellows has the advantage that it is an in-line fitting and requires no packing, as does the sliding joint... 

This is the first law of expansion joints-every expansion joint in chemically resistant masonry must end in a sliding joint or another expansion joint. If it is not so designed, the expansion joint will not function. See Drawing 4 of the wall of a brick-lined trench, below. 

In the upper left sketch, the brick on the left side of the expansion joint cannot move to the left because to do so would force it into the capping on the top of the trench wall. It will, however, be able to dose the expansion joint-moving to the right if a shear plane-a sliding joint, such as a Teflon sheet, exists under the capping. None is shown in the drawing. 

The lower right hand sketch shows the corrected design, freeing the brick to move in both directions, and the joint to open and close. Note that there are examples of both the compression joint and the sliding joint. The lower left sketch shows the sliding joint necessary under the cap for the joint to function in this design. 

If there is no veneer on the outside-only the brick cap-then the sliding joint should be placed between the cap brick and the top of the wall brick parallel with the membrane on the top of the wall. 

If quarry or ceramic tile is adhered to the concrete substrate with a strong adhesive, exactly the same rules as for the monolithic should be followed, including stress relief, since the adhesive functions in an identical manner. The tile must be cut to place the expansion jo-int in the tile exactly over the one in the substrate. On the other hand, if the floor is protected by "acid brick" laid on a membrane, the membrane acts as a "sliding joint" as described earlier, and the expansion joint in the brickwork may be offset by as much as a brick length from the point of movement in the substrate—saving the installer the cost of cutting brick to match exactly the expansion joint in the slab. 

Figure 8. Assembled steel set with two sliding joints in the site workshop (Schubert et al 2000).

The position coordinates in the local coordinate system Ci of each link of a robot is related to its previous link in the chain from Ci to C by a link transformation Tj i. This link transformation must have one variable parameter, either an angle for a rotational joint or a linear distance for a sliding joint. Thus one can find the total transformation matrix for a robot arm from the following recursive expression ... 

Since the header can slide freely on the support plate, ATm does not cause any significant stresses. Considering the lack of inspection of the sliding joint, a pessimistic assumption of a stuck up condition is made. Accordingly, ATm can induce additional stresses. 

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