Dry Pipe Research Articles

The acoustic attenuation and hydraulic roughness in a large section sewer pipe with periodical obstacles

The acoustic attenuation, relative sound pressure levels and the equivalent Nikuradse wall roughness under variable flow conditions in a 600 mm concrete sewer pipe are experimentally investigated. The values of the acoustic attenuation are obtained in the case of airborne sound propagation in the dry pipe. A range of values of the equivalent wall roughness is artificially generated by deploying a periodical array of engineering bricks. A novel method of rapid evaluation of the acoustic attenuation is proposed. The method relies upon sound reflections from the adjacent manholes. The results demonstrate that the acoustic attenuation depends strongly on the value of the equivalent wall roughness. This work can pave the way to the efficient methodology for the in-situ, physical evaluation of the equivalent hydraulic roughness of new and existing sewer networks.

Biaxial Testing to Investigate Soil-Pipe Interaction of Buried Fiber-Reinforced Cement Pipe

Three tests were performed to develop baseline information on the behavior of fiber-reinforced cement (FRC) pipe under biaxial loading. Pipes were instrumented to measure circumferential strains at various locations around the circumference and to capture changes in vertical and horizontal pipe diameter. The first two tests examined the response of wet and dry pipes under conditions simulating steadily increasing overburden pressure in an embankment loading condition, reaching earth pressures equivalent to more than 15 m. The third test examined the time-dependent response of a second, wet pipe under sustained pressure of 180 kPa. Elastic soil-pipe interaction theory shows that increases in pipe deformation lead to a redistribution of loads to the surrounding ground and reductions in bending moments. Preliminary calculations for the three pipe tests indicated that, even in the low modulus backfill, the pipe deformations were sufficient to reduce applied earth pressures on the pipes and the bending moments within them. These pipes exhibited semirigid behavior, in which bending moments were reduced below levels experienced by a rigid pipe. Bending moment decreases were greater for the wet pipe than for the dry pipe because the wet specimens had lower manufactured wall thickness and wet FRC has a lower modulus. Reductions in the modulus of the FRC material were estimated to decrease moments by approximately 30% by the end of the 50-h time period of the third test and by approximately 36% at the peak overburden pressure (300 kPa) reached during the second test.

Building for Disasters

The dry pipe system, despite its apparent safety can cause floods of rusty water if the system is not installed properly and well-maintained. Recent experiences in storage areas have shown that residual water lying in the pipes from routine tests will corrode through the pipes in less than ten years, if the pipework cannot be fully drained back due to incorrect installation. arson, electrical, workshop equipment and building repairs and renovations.

半導体製造用高機能配管「ＮＫクリーン・ＣＲドライパイプ」の開発

半導体製造用高機能配管「ＮＫクリーン・ＣＲドライパイプ」の開発

Fire Protection Systems on (WMATA) Metro

Smoke and fire detection, fire alarm and fire fighting systems for the Washington Metropolitan Area Transit Authority (WMATA) Mass Rapid Transit System, including some alternate fire fighting system designs, are presented. A combined rate-of-rise/fixed temperature fire detector is used in areas where rapid temperature changes are abnormal. Fixed temperature fire detectors are used in the other areas requiring protection. The below grade passenger stations have a wet pipe standpipe system. This system also includes a dry pipe and siamese connection to increase the volume and pressure of the water above the nominal city water pressure. The aerial and surface stations have a dry pipe standpipe system. All passenger station standpipe systems provide water to a hose valve within each fire equipment cabinet and to each angle hose valve located under manhole covers on the platform. The train tunnels also have a dry standpipe system.

Internal Deformation and Thermal Anomalies in Lower Blue Glacier, Mount Olympus, Washington, U.S.A.

AbstractIn 1957 through 1962 six deep holes were drilled by means of specially developed electrically powered hotpoints, 4 cm diameter aluminum pipes were placed in them, and annual inclinometer surveys were made to investigate the deformation field and flow law of the ice at depth. Although a strongly maritime climate with moderate temperatures implies that lower Blue Glacier should be temperate, freezing at depths as great as 200 m, sometimes even in summer, seriously hindered inclinometer surveys. This freezing cannot be due solely to chilling by winter cold and to leakage into initially dry pipes, but may also be due to wintertime changes of water Table in the glacier and to contamination of the ice by antifreeze. Another possibility, residual subfreezing zones carried down from the ice fall, seems unlikely.Because the relatively inextensible pipe slips lengthwise in the deforming hole, observations of pipe motion at best give only the two components of ice velocity perpendicular to the hole. Thus, a single hole gives two independent equations connecting the nine unknown derivatives of the velocity components; two holes give four equations: and three or more give at most six. Incompressibility of the ice, when applicable gives another. The remaining unknowns must be either neglected or estimated from assumptions about the flow field. At the Blue Glacier holes the longitudinal strain-rate is less than about 0.01 per year, becoming more extensional down-glacier and more compressional at depth, because the holes were moving through a reach in which the surface steepens and the bed becomes more steep-sided and flat-bottomed. Although the effective strain-rates are only about 0.01 to 0.1 per year, so that errors are relatively large, they are in reasonable agreement with flow laws deduced from laboratory experiments by Glen, from tunnel contraction by Nye, and from deformation of Athabasca Glacier bore holes by Paterson and Savage, except that in the range of strain-rates covered the viscosities found for Blue Glacier are about half those derived from the other studies.

Internal Deformation and Thermal Anomalies in Lower Blue Glacier, Mount Olympus, Washington, U.S.A.

AbstractIn 1957 through 1962 six deep holes were drilled by means of specially developed electrically powered hotpoints, 4 cm diameter aluminum pipes were placed in them, and annual inclinometer surveys were made to investigate the deformation field and flow law of the ice at depth. Although a strongly maritime climate with moderate temperatures implies that lower Blue Glacier should be temperate, freezing at depths as great as 200 m, sometimes even in summer, seriously hindered inclinometer surveys. This freezing cannot be due solely to chilling by winter cold and to leakage into initially dry pipes, but may also be due to wintertime changes of water Table in the glacier and to contamination of the ice by antifreeze. Another possibility, residual subfreezing zones carried down from the ice fall, seems unlikely.Because the relatively inextensible pipe slips lengthwise in the deforming hole, observations of pipe motion at best give only the two components of ice velocity perpendicular to the hole. Thus, a single hole gives two independent equations connecting the nine unknown derivatives of the velocity components; two holes give four equations: and three or more give at most six. Incompressibility of the ice, when applicable gives another. The remaining unknowns must be either neglected or estimated from assumptions about the flow field. At the Blue Glacier holes the longitudinal strain-rate is less than about 0.01 per year, becoming more extensional down-glacier and more compressional at depth, because the holes were moving through a reach in which the surface steepens and the bed becomes more steep-sided and flat-bottomed. Although the effective strain-rates are only about 0.01 to 0.1 per year, so that errors are relatively large, they are in reasonable agreement with flow laws deduced from laboratory experiments by Glen, from tunnel contraction by Nye, and from deformation of Athabasca Glacier bore holes by Paterson and Savage, except that in the range of strain-rates covered the viscosities found for Blue Glacier are about half those derived from the other studies.

Officer's Cave, a Pseudokarst Feature in Altered Tuff and Volcanic Ash of the John Day Formation in Eastern Oregon

Officer9s Cave is the uppermost of four rapidly eroding cave levels constituting a cavern complex about 700 feet long developed chiefly in clay and silt. Its outer room is 35 feet by 43.5 feet by 100 feet and slopes about 45° east into the western end of a narrow linear hill called Officer9s Cave Ridge. Dry valleys, blind valleys, hanging valleys, sinkholes, pipes, caves, and natural bridges are abundant. These, together with subterranean drainage, give the area a karstlike development. For such terrains the term “pseudokarst” is applied. These pseudokarsts are the product of piping and are fairly widespread over the world9s drylands.

DRY PIPE EXPLODES INSIDE STEAM DRUM. “Power,” June, 1936.

Journal of the American Society for Naval EngineersVolume 48, Issue 3 p. 448-449 DRY PIPE EXPLODES INSIDE STEAM DRUM. “Power,” June, 1936. First published: August 1936 https://doi.org/10.1111/j.1559-3584.1936.tb04345.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume48, Issue3August 1936Pages 448-449 RelatedInformation

Heat Transfer between Metal Pipes and a Stream of Air

The paper describes measurements on the heat transfer from iron and copper pipes of diameters ranging from to 3 inches, at various temperatures up to 90 deg. C. in air moving with velocities up to 30 ft. per sec. when the axis of the pipe is placed transverse to the stream of air. An iron pipe of external diameter inches was also tested when placed longitudinally along the direction of the air stream and subdivided into sections, the heat loss from various sections being measured. This loss is greatest at the section where the air first meets the pipe, and gradually falls off along the pipe. If the air is artificially made turbulent, the loss from all the sections shows an increase, the greatest change being shown by the first section. The heat loss from a longitudinal pipe is of the order of one-half that from a transverse pipe. A number of similar iron pipes of inches diameter were studied when arranged in banks in square formation. In this case the second layer of pipes met by the air loses more heat than the first layer, the third layer losing the same as the second. It is suggested that this is due to the eddy motion set up in the air when it passes the first layer, no further increase in the eddy motion occurring afterwards. In the diagonal formation with rows inches apart, the first section again loses least heat. In this case not only is the loss in the second row greater than that in the first, but there is a further increase in passing from the second to the third row, after which the coefficient is constant. When air impinging on a bank in staggered formation is artificially made turbulent, the heat loss from every row is increased to such an extent that the first row loses more heat under these conditions than the third row when there is no artificial turbulence. In addition, an investigation was carried out with pipes below 0 deg. C. If there is no ice or snow deposit on the pipes, the curve connecting H/kθ with Vd/ v is the same as for hot pipes. Here H is the heat loss per unit length, d the external pipe diameter, and θ the temperature excess, whilst k, V, and v are the conductivity, velocity, and kinematic viscosity of the air. Pipes below 0 deg. C. may become covered with a deposit of ice or snow, and in this case the interpretation of the results is less straightforward. If d and θ in the above formulae refer to the actual pipe diameter and temperature difference between the pipe and the air, then the smooth curve through the observations is again identical, within experimental error, with that for hot pipes. This can only be a coincidence, the insulating value of the deposit being compensated by the greater area presented to the wind, since the effective pipe diameter has become larger, and has a higher surface temperature than that of the metal. From the result for dry pipes, it would be expected that if d′ refers to the overall diameter, and θ′ represents the difference between the air and the outer surface of the deposit, this new curve would coincide with that for hot pipes. The experimental results show that this is so if the outer surface of the deposit is dry, but that if the conditions are such that water is dripping off, the heat transfer may be 30 per cent greater than the normal amount.

Triple Thermic Motor : Description, Operation and Results of a Single Expansion, Non-Condensing Steam Engine, Supplemented by the Evaporation of the Bisulphide of Carbon and Expansion of its Vapor, at Brush Electric Light Company, Cleveland, Ohio

An ordinary horizontal and cylindrical fire tubular boiler. A tubular generator in form of a cylinder boiler set horizontal in which the material of vaporization, known as bisulphide of carbon (formula CS2), is vaporized, having attached in the vapor space an ordinary perforated dry pipe. All of which is inclosed in a shell having a diaphragm plate between the outer and inner shells at both sides and at one end, thus forming an upper and lower chamber around it. The opposite end is inclosed with a deep disc or bonnet, thus forming a communication between the lower and upper series of tubes, for the proper circulation of the steam with which the CS2 is vaporized.