Temporary seal

MST Sparwite W-10 Sparwite W-20 film, temporary seal conformal coatings... 

Uncapped containers of chemicals should never be placed in a refrigerator. Caps should provide a vapor-tight seal to prevent a spill if the container is tipped over. Aluminum foil, corks, corks wrapped with aluminum foil, and glass stoppers usually do not meet these criteria, and, therefore, their use should be discouraged. The most satisfactory temporary seals are normally screw-caps lined with either a conical polyethylene insert or a Teflon insert. The best containers for samples that are to be stored for longer periods of time are sealed, nitrogen-filled glass ampoules. At a minimum, catch pans should be used for secondary containment. 

Polymer gel plugs or pill treatments are often employed to form temporary seals on holes encountered in the well bore that would otherwise permit the loss to the formation of large quantities of costly drilling fluids. They can also be used to divert injected fluids into the required zones in the formation and isolate other regions. They frequently employ the same components used in... 

When the mine ventilation, methane, and dust control plan is up for a 6-month review, all coal mines should determine satisfactory locations on the main entries for temporary seal locations. Furthermore,... 

A barometer consists of a glass tube about one meter long with one end permanently sealed. The tube is filled with Hg and all gas bubbles are removed. The open end of the tube is temporarily sealed and the tube is inverted. After submerging in a bath of Hg, the temporary seal is removed and the mercury falls to a level corresponding to atmospheric pressure... 

Ball sealers. A popular mechanical diversion method is the use of ball sealers. Ball sealers are not an entirely reliable method of diversion. However, under the right conditions, they may provide the most effective diversion available. Ball sealers were introduced in the mid-1950s. They are just what the name implies— balls that are pumped in an acidizing treatment, intended to seat on perforations to create a temporary seal. The add is thereby diverted to other perforations as the treatment progresses. 

Sticky waxes are used as thermoplastic cements. The broken pieces of a plaster impression are reassembled and held in position with sticky wax. Broken denture bases may be held in proper alignment for repair. Orthodontic apphances may be assembled with a sticky wax prior to investing and soldering. Plaster splints may be sealed to stone models in the production of porcelain or resin facings. Thus, sticky wax is useflil in almost any operation where it is desired to position and hold several small pieces in a temporary relationship. 

Vapor phase inhibitors These are used for the temporary protection of new plant in transit or prior to commissioning. Volatile corrosion inhibitors such as cyclohexylamine derivatives are used. The plant must be sealed or contained to prevent rapid loss of the inhibitor. Sachets of these materials are placed in packing cases. Papers impregnated with them are available for wrapping steel items. These inhibitors are used primarily to protect steel. 

Copper alloys are particularly prone to attack by long-chain fatty acids which are often present in sealing compositions, temporary protectives and as trace additives in many plastics under acid conditions ester plasticisers may saponify in the presence of copper giving rapid corrosion of the copper and accelerating degradation of the polymer. 

Trapped air and expansion of heated air in the soil are the cause of vesicle formation. When the air is driven out by infiltrating rain or floodwater, and cannot escape downwards, it escapes through the upper surface of the soil. When the soil surface is neither covered by stone, nor sealed by crusts, the vesicles are of a temporary nature only. When,... 

If a firewater line needs to be temporarily isolated and an isolation means is not available on the immediate portion of the system needing work, a unique solution is to use a liquid nitrogen low temperature coil line freezing apparatus. This mechanism causes an ice plug to form in the line, effectively sealing the line from leakage, during the period the temporary isolation is needed. 

After the mold has had a coat of mold release applied, it must be fully assembled. Inserts must be correctly placed in the mold and fully secured. In a complex mold it may be necessary to temporary lock the insert into place with a removable pin that is taken out after the mold is full but before the material has gelled. Any join lines that may be prone to leakage must be sealed with a silicone sealant. 

As has already been mentioned, waters that arc possessed of temporary hardness may be softened by boiling. This process is, however, very expensive and impracticable upon a large seale. A more convenient method is that of Clark, patented in 1841, according to which the excess of carbon dioxide is precipitated by addition of the requisite quantity of slaked lime. The soluble alkaline earth bicar bonates are thereby converted into their insoluble normal carbonates and separate out. The reactions involved may be represented as follows ... 

Safe havens may be rare on some sites however, many buildings can provide personnel with temporary protection until the incident has been analyzed and a decision made on the need for evacuation. To qualify as a designated temporary safe haven, a building must be reasonably well sealed against air infiltration, with adjustable ventilation systems that can reduce or close off exhaust vents and outside makeup air. Emergency procedures should state how long a building can be considered a safe haven under specified exposure conditions. 

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