Pipe End Connections

and fittings tables must specify which size of each class of pipe is threaded, flanged, or socket welded. ANSI B31.3 provides no specific guidance except that it suggests that threads be avoided where corrosion, severe erosion, or cyclic loading is anticipated. 

Hydrocarbon service above 600 ANSI Hydrocarbon service above 200 F Hydrocarbon service subject to vibration Glycol service 

A common practice onshore is to use threaded connections on 2-in. pipe or smaller, no matter what the service. It is also common to see threaded connections on 4-in. pipe and smaller in low pressure oil service. 

Bolting a raised-face flange to a flat-faced, cast-iron flange can create bending moments in the less ductile cast-iron flange, which could cause it to crack. 

The ANSI specifications allow the use of both RF and RTJ flanges. API RP 14E recommends RTJ flanges for ANSI Class 900 and higher and recommends RTJ flanges be used in 600 ANSI service subject to vibration. Onshore it is common to use RF flanges for ANSI classes through 2500. 

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Tees Tees may be cast, forged, or hot- or cold-formed from short pieces of pipe. Though it is impossible to have the same flow simultaneously through all three end connections, it is not economical to produce or stock the great variety of tees which accurate sizing of end connections requires. It is customary to stock only tees with the two end (run) connections of the same size and the branch connection either of the same size as the run connections or one, two, or three sizes smaller. Adjacent reducers or reducing elbow fittings are used for other size reductions. Branch connections (see subsection Joints ) are often more economical than tees, particularly when the ratio of branch to run is small. 

Pipe schedule and end connection for each service and pressure rating. 

It has been shown in equation 4.35 that this velocity vw is equal to the velocity of transmission of a small pressure wave in the fluid at the pressure Pw if heat could be transferred sufficiently rapidly to maintain isothermal conditions. If the pressure at the downstream end of the pipe were Pw, the fluid there would then be moving with the velocity of a pressure wave, and therefore a wave could not be transmitted through the fluid in the opposite direction because its velocity relative to the pipe would be zero. If, at the downstream end, the pipe were connected to a reservoir in which the pressure was reduced below Pw, the flow conditions within the pipe would be unaffected and the... 

GENERAL NOTE The weld deposit connecting the pipe end to the flange face at the I.D. shall not result in a weld buildup or undercut of the flange face surface. 

Reducers Reducers may be cast, forged, or hot- or cold-formed from pipe or plate. End connections may be concentric or eccentric, that is, tangent to the same plane at one point on their circumference. For pipe supported by hangers, concentric reducers permit maintenance... 

The surface condensers are here shown, G G G. This process of condensation was introduced and patented by Messrs. Pontieex and Wood of London, who have recently patented a simple and efficient method of connecting the pipes—admirably adapted for the colonies, and all places where skilled labor is difficult to be obtained. The condensers consist of one or more series of copper pipes, fixed to boxes at each end, with partitions to direct the current of the vapor. Above each series of pipes is iked a trough always kept full of water, and so constructed that the water trickles in a gentle shower, uniformly spread over the pipes, so as to keep them well covered with a thin film of water the lowest pipe is connected with a small pump, workod by the engine, which draws the condensed... 

K—Fig. 42—in connection with the cistern, i, is carried along the top between the two rows, to each set of which it sends out an arm, l, pierced with small holes, which allow a fine stream of water to fall on the tops of the pipes, end to trickle down tho Bides, and thus cool them effectually. 

Concentric-orifice devices can be easily installed in high-pressure lenses. The high-end- and the low-end connection of such devices could be coupled with differential pressure transmitters, for example, with the before-mentioned devices of [54]. The devices are mounted in different ways. Mostly, the open pipe technique is used. Furthermore, both connected sides of the transmitter are fed with an inert gas, for example, nitrogen. For cases where the systems must separated, membrane devices can be arranged between them. All the mentioned orifice devices are technically proved and are applied in the high-pressure area. 

The nitrating acid is metered by means of tipping a vessel fixed on a horizontal shaft (Fig la). Acid flows into the vessel (1) from a pipe ending inside a container constructed of acid-resistant steel or lead, in which the tipping vessel is located. The stream of acid fills the vessel, and as a determined weight is reached it tips over and another empty vessel swings into place under the acid inlet pipe. This fills in turn and tips over to pour off its contents, and so the cycle continues. A volume-meter connected to the equipment indicates the volume of liquid... 

The inlet pipes of the two starting reactants to the batch vessel were simply connected to the StarLam mixer [67]. The only difference to the previous feed lines was the installation of filter cartridges before the entries to the microstructured mixer, necessary to avoid blocking of the reactor. The pressure drop in the lines was lower than 3 bar so that it was possible to keep the pumps used before in the plant. At the outlet of the reactor, a tube reactor was installed. During optimization it was found that it is sufficient to insulate this tube to reach the temperature needed to finish the reaction. The pipe ended directly in the batch vessel where the second endothermic reaction step was carried out as before. 

Instruments IR-85 Fourier Transform infrared spectrometer, through an IBM GC-IR interface. The interface consisted of a gold-coated Pyrex light-pipe with potassium bromide windows. A scan rate of 6 scans/sec and a spectral resolution of 8 cm- - were used for data acquisition. Samples were introduced into the system via splitless injections. A fused silica capillary column, 30 m x 0.32 mm i d DB-WAX (dj 1.0 pm), was employed with the outlet end connected directly to the GC-IR light-pipe entrance. Helium was used as the carrier gas at an average linear velocity of 41.4 cm/sec (35°C). No make-up gas was employed in the system. The column temperature was programmed from 35°C to 180°C at 2°C/min. The GC-IR light-pipe assembly was maintained at 170°C. 

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