Anchor holes

Polyester anchoring grouts are of two types pourable grouts and thixotropic grouts. Pourable products are designed for vertically downwards or declining anchor holes prior to insertion of the anchor unit. The... 

Fig. 5.3.1 e-f Top view of surface-micromachined cantilever beams anchored in two different ways left anchor hole right unremoved sacrificial layer... 

Hot-dip galvanizing is by far the most common and effective form of corrosion protection for structural steel and anchors used in the petrochemical industry, unlike the building industry which more typically uses black, primed, or painted steel. Secondly, plate washers can result in larger base plates and anchor spacing to avoid interferences, especially if larger anchor hole diameters are used. 

Table 3.3 Recommended Maximum Sizes for Anchor Holes in Base Plates and Minimum Fabricated Washer Sizes...

Holes are next cut all the way through the first oxide layer (ANCHORl) to anchor structures defined in Polyl to the substrate after the PSG sacrificial spacer layer has been etched. An example is shown in Figure 1.8 [7]. Note that the polysilicon is a conformal coating, so that topographic features, such as the anchor holes, are replicated in the layers deposited on top of them. This replication of topography can give rise to mechanical interferences for features defined in the overlayers. 

A common mistake made by those who are first learning to use a surface micromachining process is to leave out anchors. Since you must specify where a hole in this layer is to be placed, it is easy to leave out the anchor hole. If no anchor hole is specified, the polysilicon that is deposited over the oxide will be released during the sacrificial etch and float away. A good practice to avoid this common mistake is to take cross sections of the thin-film stack to make sure that all structures are anchored. An example of a bond pad that was not anchored and was released during the sacrificial etch is shown in Figure 1.9. 

For free-field stations, it is usual to build a small concrete pier on which the accelerometer (or accelerograph if the sensor is inside it) must be firmly anchored so a strong motion cannot move the instrument relative to ground Most commercial instruments include a suitable base with anchoring holes or a similar system. Other materials for pier, like a table made with steel bars, are not suitable since it may resonate with very low damping in the seismic band of interest. 

The derrick or mast must also be designed to withstand wind loads. Wind loads are imposed by the wind acting on the outer and inner surfaces of the open structure. When designing for wind loads, the designer must consider that the drill pipe or other tubulars may be out of the hole and stacked in the structure. This means that there will be loads imposed on the structure by the pipe weight (i.e., setback load) in addition to the additional loads imposed by the wind. The horizontal forces due to wind are counteracted by the lattice structure that is firmly secured to the structure s foundation. Additional support to the structure can be accomplished by the guy lines attached to the structure and to a dead man anchor some distance away from it. The dead man anchor is buried in the ground to firmly support the tension loads in the guy line. The guy lines are pretensioned when attached to the dead man anchor. 

Often in open-hole completion operations and in production, it is necessary to shut off water flows. Additional cementation methods are used to provide an anchor for testing tools or for other maintenance operations. 

The dimensions of typical standard saddle designs are given in Figure 13.26. To take up any thermal expansion of the vessel, such as that in heat exchangers, the anchor bolt holes in one saddle can be slotted. 

When specified, the vendor shall test to demonstrate that the pnmp and its baseplate assembly, when anchored at foundation bolt hole locations with any bearing housing support discoimected, are in compliance with 3.3.5. The pump casing shall be snbjected to moments MYq and MZ applied to either nozzle, bnt not both, snch that the corresponding shaft displacements can be measnred and recorded. MY and... 

L.4.7 After the baseplate is installed, the anchor bolt sleeve holes shonld be filled with a nonbonding material or the chosen gront, depending on the user s preference. This shonld be done before the main grouting of the baseplate. 

Dimensionai outline drawings shaii indicate the toierance for pump suction and discharge nozzie face and centreline iocations referenced from the centreiine of the nearest basepiate anchor bolt hole. The centreline of baseplate anchor bolt hole locations shall indicate the tolerance from a common reference point on the baseplate. 

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