Branch pipe

Branch Welds These welds eliminate the purchase of tees and require no more weld metal than tees (Fig. 10-127). If the branch approaches the size of the run, careful end preparation of the branch pipe is required and the run pipe is weakened by the branch weld. See subsection Pressure Design of Metallic Components Wall Thickness for rules for reinforcement. Reinforcing pads and fittings are commercially available. Use of the fittings facilitates visual inspection of the branch weld. See subsection Welding, Brazing, or Soldering for rules for welded joints. 

Selten-gummi, n. side wall (of a rubber tire), -isomerie, /. chain isomerism, -kante, /. lateral edge, -kette, /. side chain, -ketten-isomerie, /. side-chain isomerism, -kraft, /. component force, component, -lage,/. lateral position, -l ge, /. length of a side, lateral length, -riss, m. side elevation. -lohr, n., -rohre,/. side tube, branch tube, branch pipe, seitens, adv. on behalf (of), on the part (of), seltenstandlg, a. lateral. 

Example 3-14 System Head for Branch Piping with Different Static Lifts... 

Air distributors. Improvements in the metallurgy, refractory lining of the outside branches, and better air nozzle design, combined with reducing L/D of the branch piping, have reduced thermal stresses, particularly during start-ups and upset conditions. 

Branch pipe L/D ratio of less than 10 to minimize the support requirement and vibration... 

Branch pipes cause the minimum disturbance if they can be taken off the main piping by swept T pieces rather than by right-angled junctions. Where the latter are unavoidable the diameter of the branch main should be as generous as possible. If connecting pieces are not used, branch pipes should be set at a shallow angle with the main piping and should not protrude into the latter. 

Hot gas. A branch pipe from the compressor discharge feeds superheated gas to the coil. The compressor must still be working on another evaporator to make hot gas available. Heat storage capsules can be built into the circuit to provide a limited reserve of heat for a small installation. 

Pumps, centrifugal system performance, 197 Affinity laws, 201-203 Branch piping, 200 Calculations, 199... 

In burn-out experiments, a test section is part of a loop which may be open or closed, and the question arises as to whether or not any of the loop equipment, such as condensers, heaters, pumps, or pipe fittings, have any significant effect on the burn-out flux. This issue came to prominence at the Boulder Heat Transfer Conference in 1961 with a Russian paper by Aladyev (A4) describing burn-out experiments in which a branch pipe, connecting to a small vessel, was fitted close to the test section inlet. The test section itself was a uniformly heated tube 8 mm in diameter and 16 cm long. The results are reproduced in Fig. 9, and show burn-out flux plotted against exit steam quality. Curve (A) was obtained with the branch vessel filled with cold water,... 

Equipment branch general symbol Note. The upper representation does not necessarily imply a flange, merely the termination point. Where a breakable connection is required the branch/pipe would be as shown in the lower symbol H ... 

NPS 2) nor one-fourth the nominal size of the run. The minimum wall thickness of the coupling anywhere in the reinforcement zone (if threads are in the zone, wall thickness is measured from root of thread to minimum outside diameter) shall be not less than that of the unthreaded branch pipe. In no case shall a coupling or half coupling have a rating less than Class 2000 per ASME B16.ll. 

Area A3 is the area resulting from excess thickness in the branch pipe wall... 

If the allowable stress for the branch pipe wall is less than that for the run pipe, its calculated area must be reduced in the ratio of allowable stress values of the branch to the run in determining its contributions to area A3. 

Material used for reinforcement may differ from that of the run pipe, provided it is compatible with run and branch pipes with respect to weldability, heat treatment requirements, galvanic corrosion, thermal expansion, etc. 

Calculations of displacements and rotations at specific locations may be required where clearance problems are involved. In cases where small-size branch pipes attached to stiffer run pipes are to be calculated separately, the linear and angular movements of the junction point must be calculated or estimated for proper analysis of the branch. 

Area A2 is the area lying within the reinforcement zone resulting from any excess thickness available in the branch pipe wall, i.e., A2 = 2L(Tj, - tj,). 

Area available for branch reinforcement in branch pipe mm2 in.2... 

Tb Branch pipe wall thickness (measured or minimum per purchase specification) mm in. 

D = outside diameter of run d = outside diameter of branch pipe Dc = corroded internal diameter of run dc = corroded internal diameter of branch pipe D0 = corroded internal diameter of extruded outlet measured at the level of the outside surface of run... 

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