Pipes/piping joining

The worm-type drip condenser has been in use for many years in one form or another. One type consists of six or eight horizontal sheet-metal pipes joined at the ends by elbows to form a continuous series (fig. 3). The first two lengths of pipe from the top are 7 or 8 inches in diameter the rest are reduced successively in size, the last one, from which the condensed oil and water flow, being 2 or 2-1/2 inches in diameter. 

Fig. 7-9. Corrosion cell between galvanized and copper pipes joined together.

Aquatic lead pollution has been an environmental and public health issue since ancient times (3). Widespread use of lead pipes, lead-lined storage tanks, and pipes joined with lead-based solder led to contamination of drinking water... 

A major weakness in this sampling approach is the dilution of water that has stood in lead pipe-work with water that has stood in non-lead pipe-work between the lead pipe-work and the tap outlet. To illustrate, let us consider a lead pipe joined to a copper pipe up to the tap. A 12 mm internal diameter copper pipe of 8.8 metres length has a volumetric capacity of 1 litre. If the copper pipe between the lead pipe and the tap is 4.4 metres in length, the first draw one litre sample will comprise 50% water that stood in the copper pipe and 50% water that stood in the lead pipe, a 50% dilution effect. If the copper pipe is 8.8 metres in length, or greater, no water that stood in the lead pipe will be capmred by the first draw one litre sample. This assumes simple plug flow in the pipes concerned, which is reasonable at the flow rates normally experienced (about 0.1 litre per second, that is 6 litres per minute) as the flow should be turbulent... 

Pressure drop in mechanical pipe joining test method ISO 4059. 

Double-ended guillotine break 1 s of a pipe joining a pump to the core grid plate in ... 

From alternator to the pipe joining the recuperator and the gas cooler, flow will travel to gas cooler (4)... 

The hot leg piping joins the reactor outlet to the turbine inlet. Both of these component interfaces would have required significant development, including potentially the development of bimetallic joints and methods for Insulation containment. At the reactor outlet there was the possibility of a bimetallic joint between an inner refractory metal alloy reactor vessel and the Ni-base superalloy piping liner, if a Ni-base superalloy was chosen as the liner material. Another dissimilar joint would have occurred between the cast Ni-base superalloy turbine inlet and the wrought Ni-base superalloy outer piping. Finally, should a refractory metal alloy liner have been selected, the end caps for insulation containment would have required bimetallic Joints. 

Most of the adhesively bonded pipe joints used in engineering, such as adhesively bonded socket joints, butt-weld and strap joints and heat activated coupling joints etc., can be basically regarded as two pieces of composite pipes joined by a connection coupler via the bonding adhesive, as shown in Figure 5. In order to reduce the stress concentration influence on the joint system, the smart beam-like joint concept was extended to develop a novel adhesively bonded smart composite pipe joint system by integrating the smart piezoelectric... 

As early as 1966, natural gas was available to all of the lower 48 states in the United States. During the period 1967—1990, the U.S. transmission system grew from 362,700 km to 450,800 km. Over this same time period, the distribution mains increased from 867,800 km to 1,347,000 km. As plastic pipe and reUable joining technology became available, the use of plastic pipe expanded to include the distribution of gas in low pressure systems. By 1990, approximately 24% of the U.S. distribution system was based on plastic pipe (1). 

The hydrocarbon gas feedstock and Hquid sulfur are separately preheated in an externally fired tubular heater. When the gas reaches 480—650°C, it joins the vaporized sulfur. A special venturi nozzle can be used for mixing the two streams (81). The mixed stream flows through a radiantly-heated pipe cod, where some reaction takes place, before entering an adiabatic catalytic reactor. In the adiabatic reactor, the reaction goes to over 90% completion at a temperature of 580—635°C and a pressure of approximately 250—500 kPa (2.5—5.0 atm). Heater tubes are constmcted from high alloy stainless steel and reportedly must be replaced every 2—3 years (79,82—84). Furnaces are generally fired with natural gas or refinery gas, and heat transfer to the tube coil occurs primarily by radiation with no direct contact of the flames on the tubes. Design of the furnace is critical to achieve uniform heat around the tubes to avoid rapid corrosion at "hot spots."... 

Venturi Meters The standard Herschel-type venturi meter consists of a short length of straight tubing connected at either end to the pipe line by conic sections (see Fig. 10-15). Recommended proportions (ASME PTC, op. cit., p. 17) are entrance cone angle Oti = 21 2°, exit cone angle Cto = 5 to 15°, throat length = one throat diameter, and upstream tap located 0.25 to 0.5 pipe diameter upstream of the entrance cone. The straight and conical sections should be joined by smooth cui ved surfaces for best results. 

When both components of a threaded joint are of weldable metal, the joint may be seal-welded as shown in Fig. 10-130. Seal welds may be used only to prevent leakage of threaded joints. They are not considered as contributing any strength to the joint. This type of joint is limited to new construction and is not suitable as a repair procedure, since pipe dope in the threads would interfere with welding. This method provides tight joints with a minimum of welding labor. When threaded joints used to join materials with widely dinerent coeffi-... 

These alloys are available in the cast form only. Pipe and fittings are cast with the upset ends being joined by split flanges. IntegraUy cast flanged pipe is also available. Allowable working pressures cannot be... 

Crete piping systems can be lined with special salt-glazed vitrified-clay liner plates, joined with a die-cast aspnalt joint. Concrete pressure pipe is competitive with cement-lined ductile iron for underground plant water systems. 

Plastic Pipe In contrast to other piping materials, plastic pipe is free from internal and external corrosion, is easily cut and joined, and does not cause galvanic corrosion when coupled to other materials. Allowable stresses and upper temperature limits are low. Normal operation is in the creep range. Fluids for which a plastic is not suited penetrate and soften it rather than dissolve surface layers. Coefficients... 

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