Expansion joints additives

To protect terminal equipment or other (weaker) portions of the system, restraints (such as anchors and guides) shall be provided where necessary to control movement or to direct expansion into those portions of the system that are adequate to absorb them. The design, arrangement, and location of restraints shall ensure that expansion-joint movements occur in the directions for which the joint is designed. In addition to the other thermal forces and moments, the effects of friction in other supports of the system shall be considered in the design of such anchors and guides. 

The following are specific considerations to be evaluated by the designer when specifying expansion joint requirements, in addition to the guidelines given in EJMA standards ... 

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. 

The use of expansion joints (bellows, in this case) which were improperly installed may have been a principal reason for the accident. This provides additional reasons not to use expansion joints (except in special exceptional circumstances). 

If it is impractical on account of size to contour the bottom, it is recommended that at least the sides be contoured. The bottom can be provided for with peripheral squeeze joints and additional expansion joints. However, minimum thickness of the brick walls will still be possible and except in rare occasion without requiring expansion joints in them." (Reference 8, p 64). 

Locations of expansion joints in trenches must be planned, not only to accommodate thermal expansion and brick growth, but to protect brick at outside corners from being pushed off the membrane by back pressure from deformable elastomeric material in the expansion joints. In trenches, therefore, in addition to the normal spacing of expansion joints and the placing of expansion joints around fixed objects and over all points of movement and cold seams and control joints in the substrate, at not more than 20 ft. intervals (or evenly spaced apart at lesser distances if the length does not divide evenly into such intervals) they should be placed in both directions at not more than 3 ft. or less than 2 ft. from all changes in direction and intercepts, and before all step changes in depth in trenches. 

From the standpoint of long life and freedom from maintenance, dished, hemispherical and cone bottoms are the best for cylindrical tanks, and are the designs of necessity if a vessel is to be "prestressed" (see Chapter 47), or if there is a desire or necessity to eliminate expansion joints. Flat bottoms, unless provided with properly designed expansion joints, will heave upward with brick growth. In addition, adequate and frequent stiffening is required if flexing and... 

When a monolithic surfacing is applied to a concrete substrate, in most cases much of the cure shrinkage of the concrete has already taken place. However, the concrete contractor will have, perhaps, installed expansion joints in the slab, and should have cut in or formed control joints as well, so that any future shrinkage will occur at these intentionally weakened parts of the slab rather than in random locations. In addition, there will be "cold seams"—locations where a concrete pour was completed one afternoon and another pour made a day or so later, or fresh concrete was poured against dry, partly cured concrete. This joint is also weak, and with shrinkage of concrete over the years will probably also crack. 

Addition of molybdenum to nickel-chromium alloys produces grades such as Inconel 625 and Hastelloy C276. These alloys are practically unaffected by caustic up to at least 320°C [135]. Their high costs limit their application. An exception is the use of Alloy 625 in high-pressure steam expansion joints. This avoids the caustic... 

Type 321 is similar to 304 but with titanium addition five times the carbon content that reduces carbide precipitation during welding and in 425-815 C service. It has excellent corrosion resistance toward most chemicals and oxidation resistance up to SIS C. Aircraft exhaust manifolds, boiler shells, process equipment, expansion joints, cabin heaters, fire walls, flexible couplings, pressure vessels. 

Compressors, pumps Vibration-isolated mounting in enclosed soundproofed rooms. Machines preferably separated from one another by partitions or with individual enclosures. Ventilation or air intake openings of such rooms should have louvred sound attenuators. Intake and outlet silencers for the compressors. Pressure pipelines to have sound-damping expansion joints and acoustically sealed wall inlets. Pressure release pipelines to have silencers. Additional sound insulation for compressed air pipelines to suppress rushing noises. Sound-insulated enclosed portable compressors represent the current "state of the art" for use in quarrying operations. 

Bund wall expansion joints are important to ensure ongoing bund structural integrity. In addition they need to provide a liquid tight, fireproof joint. 

Where this structure supports slabs in the annulus, care has be taken to insure minimum resistance from these slabs by the use of expansion joints between the cylinder wall and the slabs. In addition, low friction bearing pads have been used under the slab support steel at the steel brackets on the primary containment wall to insure that there is essentially no interaction between the primary and secondary containment. 

It is a countercurrent flow unit. TempcraEuie crossover is not a problem. 2) suitable for high pressure service, since both she] 1 and tubes are pipes, 3] applicable to fluids with large temperature diffnence withour expansion joint, 4] easy to install, and add on additional units, standant design, usually nor cusiom made. Its delivery time is short, 6) u is easy to maintain - clear, ir.[Pg.74]

Provides additional thermal insulation to expansion joint. 

PiUows must be manufactured incorporating cushion pins equally spaced across the pillow to keep the layers of insulation bound together. In addition pillows should be either pinned to the side walls or sleeves as described above or flanged so they can be mounted between the expansion joint and mounting steelworks. See Fig. E-54. 

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