Disassembly and repair

Easy disassembly and repair of joints No problems with solvent or solvent vapors... 

The need to disassemble and separate the parts at some later date without undue difficulty is becoming more important. This is critical both for ease of repair and for recycling the individual components when they reach the end of their service life. These issues are discussed in more detail in Section 6.8.8. Disassembly and Repairs . 

Many anaerobie adhesives and sealants may require a relatively low strength so that the eomponents can be disassembled for repair or replacement. Many liquid plasticizers have been used for this purpose [62], but the use of a low-molecular-weight polyester has been found to be advantageous [63]. The toughness properties of anaerobic adhesives can be enhanced by the addition of a reactive elastomer [64]. The heat resistance of anaerobic adhesives and sealants can be enhanced by the addition of a bismaleimide... 

The development of electronics equipment is a good example of how material consumption can be reduced by miniaturisation. Size reduction is mainly due to new developments within the field of electronics, allowing designers to make their products smaller, thus consuming less material per functional unit. However, making products smaller may pose problems for recycling and repair, since disassembly may become more difficult and time consuming. Well-performed miniaturisation must allow for rapid disassembly to avoid unnecessary added cost to the life cycle of the assembly. 

The schedule to overhaul a used hoist can take several months to estabhsh. A complete Hst of required replacement parts cannot be defined at the beginning of the overhaul operation as the hoist must be completely disassembled and each part inspected prior to procurement of all the required replacement components. Likewise, the complete cost of the hoist refurbishment is in general not known until the complete hst of replacement parts has been estabhshed. The entire hoist must be fully inspected to determine which parts need to be repaired or replaced. This process can take several months. The hoist typically must be disassembled and moved to a shop environment to complete a full dimensional and non-destructive test inspection. If any of the used hoist major components are found to be defective and need to be replaced, new... 

Locksmiths open, repair and disassemble locks, and repair and replace worn locks. They change lock combinations using hand tools or other special tools. They make keys, cut new or duplicate keys using special key-cutting machines. They shorten tumblers using files and insert new and repaired tumblers into locks. They move lock picks and cylinders to open door locks without keys. They open safe locks by drilling, or by listening to lock sounds (Adams 1999). 

The most commonly used adhesively bonded joining methods for composite pipes are (1) adhesive-bonded socket joints, (2) tubular lap joints, (3) heat-activated coupling joints (similar to (1)) and (4) flanged joints (see Fig. 18.7). The first three configurations are considered as permanent joints, while the flanged joints provide the opportunity and ease of quick assembly/disassembly for installation, inspection, and repair. Nevertheless, most composite flanges are... 

Portable Hand-Powered Crane. The portable hand-powered crane is similar in design to a small manual-lift truck, except that the load-carrying forks have been replaced by a boom and hook. This equipment is commonly used to move and position work pieces into and out of process equipment where volumes do not warrant a permanently installed hoisting system. It is also frequently found in maintenance and repair shops to assist in the disassembly and reassembly of in-plant equipment. Lifting is accomplished either through a hand winch and cable system or a manually operated hydraulic system. Typical lifting capacities are limited to 2000 lb (900 kg) or less. 

After the cause was identified, all welding seams, not only those directly affected, were removed on site under extremely difficult confined conditions and rewelded using improved welding parameters. This process took approximately 4.5 months, and was completed in accordance with a schedule drawn up for the operation. Ultrasonic tests shortly after repair and recharging with sodium and one year later showed no evidence of cracks. An examination of the complete plant for similar evidence showed that the cold trap vessels were also affected. However repair work on these was very much easier as disassembly and reassembly were relatively simple and repairs could be carried out in the workshop. 

According to Narayan (2012), maintenance concerns the combination of all technical, administrative, and managerial actions during the life cycle of an item, intended to retain it in, or restore it to, a state in which it can perform the required function. The conclusion from the presented definition is the following maintenance is not only technical tasks, such as disassembly and replacement of spare parts, lubrication, and repair. In practice, maintenance has a much wider spectrum involving numerous additional tasks (Jasiulewicz 2013). 

When thermally dissimilar materials are bonded together, residual thermal stresses are developed that usually detract the remaining strength available for transmitting mechanical loads. These phenomena occur whenever titanium edge members are bonded around the edges of composite panels to permit the use of mechanical fasteners during final assembly of the structure or to permit disassembly in service for inspections and repairs. These thermal stresses... 

As the final part of the repair proeess, the expander underwent a trial assembly at the repair faeility. The aetual job assembly and disassembly fixtures were used during the trial assembly. No signi-fieant problems were eneountered and internal elearanees were to speeifieations. As the assembly bed plate at the repair faeility did not exaetly duplieate the user s baseplate, there was some eoneern that readjustment would be required in the field to obtain elearanees. To faeilitate the field assembly proeess, appropriate pins and fixtures were manufaetured to hold axial and eoneentrie positions of the diffuser and stator as they were in die repair shop. The entire expander trial assembly was eompleted one mondi ahead of sehedule. 

Designers must keep in mind that modem aircraft will likely be in service for thirty years and that repair of adhesive bonded structure will be inevitable. They must allow for reasonable disassembly of bonded stmcture for repair access as well as anticipate repair procedures that will not be unduly difficult for airline repair stations. 

Repair and Reuse After Explosion. Although the risk of a high order detonation of a munition during disassembly is low, this hazard does exist. In the event of such an incident, it is a design requirement for the containment rooms to suffer only minimal damage and allow rapid refurbishment. To assure this capability, the containment room structural design criteria are more conservative than Department of Defense Explosive Safety Criteria would normally require. This is considered appropriate since vapor containment is so critical in this facility. 

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