Pipe plugs

Plugs are sometimes used in pipeline repair they create a vapor barrier when a line has been isolated and depressured, but has not been completely cleared of flammable, combustible, or toxic materials. Expandable plugs are also used to isolate sections of gravity drain systems such as sewers. Examples include plumbers plugs— which consist of two parallel disks that compress an elastic material together to form a seal on the inside diameter of the pipe—and inflatable bladders— which are inflated either pneumatically or hydraulically 

The following precautions should be considered when using pipe plugs  

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Biomass gasification offers the potential for producing a fuel gas that can be used for power generation system or synthesis gas applications. The volatile matter contains a considerable amount of tar which is a complex mixture of aromatics. Despite extensive research efforts tar formation which causes the pipe plugging and the reduction of conversion efficiency is still a major problem in biomass gasification systems [1-6]. 

Ferrous Pipe Plugs, Bushings, and Locknuts With Pipe Threads... 

The choice and properties of the aeration gas are important factors for maintaining stable standpipe operation. The condensate source for steam aeration can cause several problems. If the steam is not kept dry, the condensate can lead to stress cracking of the tap piping, plugging of the tap nozzle with mud, erratic aeration rates, orifice erosion, and potentially catalyst attrition. Similar problems can occur with wet fuel gas as an aeration source. When possible, dry air and/or nitrogen are preferred rather than steam as aeration media for standpipes. However, in actual... 

The older literature reports the synthesis of phosphorus-(V) sulfochloride by reaction of phosphorus (V) chloride with phosphorus (V) sulfide in a sealed tube at 120°. Experience has shown that pressures as great as 700 p.s.i. may result under these conditions, indicating that an autoclave or bomb should be used. In the absence of these, the reactor shown in Fig. 8 is suitable. It consists of an oil bath containing a lecture bottle fitted with a pipe plug (iron pipe size, % in.), a thermometer, and a knife type of immersion heater. Although no difficulty has been experienced in the use of this reactor, it is well to keep it behind a barricade during the reaction. 

In a hood, 211 g. of powdered phosphorus(V) chloride (1.01 mols) is intimately mixed with 75 g. of powdered phosphorus ) sulfide (0.338 mol) in a 500-ml. beaker. This mixture is then transferred to the lecture bottle. Use of a 150-mm. short-stemmed funnel and a stirring rod facilitates this transfer and keeps the pipe threads clean. After treatment with pipe-joint compound, the pipe plug is screwed into place. (A satisfactory pipe-joint compound can be made by grinding litharge and glycerol together.)... 

Pipe Plug of Wear or Erosion-Resisting Material... 

Solid pipe plug Two (2) eteel pipe couplings Metal strap - roughly 1/8" x 1/4" X 5 ... 

Drill a hole in the center of the pipe plug juet Urge enough for the nail to fit through. 

Push nail through plug until pipe Plug head of nail is flush with square end. Cut nail off at other end 1/16" IS8 cm) away from plug. 

Steel coupling Solid 3/4" pipe plug Metal strap (1/4 x 1/14 x 4 )... 

Drill a hole through center of pipe plug large enough for nail to pass through. 

Screw the pipe plug tightly into the pipe cap. 

Dicoronylene is the predominant molecule that causes process pipe plugging [231-Its low solubilities in process oils are only on the order of a few parts-per-million, so saturation is reached very early in the process run. This PAH is so large that it is not volatile enough for gas chromatographic analysis and too absorbing for HPLC analysis. The low solubility requires a very sensitive analysis. 

Plug Flow. Alternate plugs of liquid and gas move along the upper part of the pipe and liquid moves along the bottom of the pipe. Plug flow occurs for liquid velocities less than 2 ft/sec (0.6m/sec) and gas velocities less than about 3 ft/sec (0.9 m/sec). 

The slurry velocity at which a particle bed forms is defined as critical deposition velocity, VD, and represents the lower pump rate limit for minimum particle settling. A further decrease in slurry velocity leads to increased friction loss, as indicated by a characteristic hook upward of curve A, and may also lead to pipe plugging. After shutdown, if flow rate over the settled solids is gradually increased, a response similar to curve A of Figure 16 is once again obtained. With increasing nominal shear rate, wall shear stress decreases until a minimum is reached and then increases rapidly thereafter. The fluid velocity that corresponds to this minimum stress value is the critical resuspension velocity, Vs. 

Figure 7-93. (a) pipe plug stops small leaks in thermowell, (b) use shut-off valve and pipe nipple for large thermowell. 

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