Manifold installation

The process data from manifold installations can hardly be transferred to chamber-type plants. This applies, practically, also to the process transfer from belljar-type installations to chamber plants. Results obtained in laboratory plants of the chamber type must be analyzed carefully, if they are be transferred to another plant. If the product, the layer thickness of the product and the vials or trays are identical, the following conditions should be observed and compared ... 

For very low flow rates the orifice plate is often incorporated into a manifold, an integral part of the differential-pressure transmitter. This provides a convenient compact installation. 

At the Lipari Landfill site in New Jersey, the gas venting system installed in 1983 consisted of two underground 4-inch (10-cm) perforated PVC pipes and five vent risers. Two parallel PVC pipes were installed 200 feet apart prior to cap emplacement during the period of wall construction and were placed about 3 feet beneath the finished grade. The vent risers were connected to the buried manifold pipes and consisted of open pipe installed perpendicular to the underground pipes and the ground surface. Filters were not attached to the riser exit points (U.S. EPA, 1987). 

This section describes the requirements for the design and installation of pressure relief valve inlet and outlet piping manifolds and valving, including safety valve and flare headers. 

It was not nndl the 1950s that detonation flame arresters made of crimped metal ribbon elements were developed and began to be used more freqnendy (Binks 1999). The major impetus for die use of crimped metal ribbon detonation flame arresters in the US was the enactment of clean air legislation (Clean Air Act of 1990) which inadvertently created a safety problem by requiring reductions in volatile organic compound (VOC) emissions. To do this, manifolded vent systems (vapor collection systems) were increasingly installed in many chemical process industry plants which captured VOC vapors and transported them to suitable recovery, recycle, or destruction systems. This emission control requirement has led to the introdnction of ignition risks, for example, from a flare or via spontaneous combustion of an activated carbon adsorber bed. Multiple... 

An in-line detonation flame arrester must be used whenever there is a possibility of a detonation occurring. This is always a strong possibility in vent manifold (vapor collection) systems, where long pipe runs provide sufficient run-up distances for a deflagration-to-detonation transition to occur. Figure 3-3 shows the installation of in-line arresters of the detonation type in a vent manifold system. 

NFPA 30 (2000), Section 5.10, applies to vapor recovery (vent manifold) and vapor processing systems where the vapor sonrce operates at pressnres from vacnnm np to and inclnding 1 psig. Snhsection 5.10.7.6 is concerned with flame propagation hazards, hnt is not specific ahont installing flame arresters. It states as follows ... 

It is emphasized that the system shown in Figure 5-13 represents only a simplification of actual plant installations, which may he more complex. If it is not obvious at which point ignition is likely to occur, a flame arrester installed in an actual plant may have to he selected to face a comhination of the conditions shown in Figure 5-13. Therefore, for manifolded vent systems, the arrester should he a hidirectional, detonation type, and hoth sides of the arrester element should he provided with thermocouples to detect a stable flame. 

For detonation flame arresters that are installed in manifolded vent systems, similar considerations as above apply to prevent overpressnre or vacnnm damage of atmospheric pressnre tanks. 

When in-line detonation flame arresters are installed in single or manifolded vent systems, consideration mnst be given to the design of the system (flame arrester and piping). The following design practices shonld be considered ... 

Figure 7-11. Safety valve and rupture disk installation using pressure rupturing disk on inlet to safety relief valve, and low pressure disk on valve discharge to protect against back flow/con-osion of fluid on valve discharge side, possibly discharge manifold. By permission, Fike Metal Products Div., Fike Corporation, Inc.

Figures 7-10 and 7-18 illustrate a few typical safety valve installations. Care must be shown in designing any manifold discharge headers collecting the vents From several valves. Sharp bends are to be avoided. Often two or more...

This illustrates individual multizone PLATECOIL as typically installed in agitated vessels The stress pads, hemmed edges and manifolds are omitted for clarity. Installation may be by welding or bolting. 

Figure 10-161. This figure illustrates an individual multizone Platecoil as typically installed in agitated vessels. The stress pads, hemmed edges, and manifolds are omitted for clarity. Installation may be completed by welding or bolting. (Used by permission Cat. 5-63, Sept. 1994. Tranter , Inc.)...

A University Lab expansion includes installation of a distribution system to — provide gaseous oxygen from manifolded cylinders to a biological laboratory. 

Heat Transfer Heat-exchange surfaces have been used to provide the means of removing or adding heat to fluidized beds. Usually, these surfaces are provided in the form of vertical or horizontal tubes manifolded at the tops and bottom or in a trombone shape manifolded exterior to the vessel. Horizontal tubes are extremely common as heat-transfer tubes. In any such installation, adequate provision must be made for abrasion of the exchanger surface by the bed. The prediction of the heat-transfer coefficient for fluidized beds is covered in Secs. 5 and 11. 

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