Vents entry

Explosion prevention by inerting has several advantages over explosion protection techniques, such as explosion venting. For example, with successful inerting, fires or business interruptions cannot occur. Nevertheless, beware of the potential of asphyxiation with inerting proper vessel entry procedures must be implemented and occasionally it may be prudent to monitor for oxygen in workplaces. 

Each PR valve must be installed so that the bonnet vent does not allow released vapors to impinge on lines or equipment, or towards personnel walkways. Where necessary, a short nipple and elbow should be added to direct flow away from such areas. In these cases, the vent piping should discharge horizontally to avoid entry of rainwater and debris, and should terminate in a position which is accessible for leak testing. 

This means that thermostatic balanced pressure steam traps which open when their element senses a temperature somewhat below that of saturated steam at the pressure existing within the steam space are very effective when used as automatic air vents. They are connected to a steam space at any location where air will collect. Usually this means at any remote point from the steam entry, along the path the steam takes as it fills the steam space. 

Since much of the vented material will be liquid, separators such as knockout pots or tangential entry separators can provide disengagement and possible recovery. Figure 5 is a typical vapor-liquid separator design found to be effective for these applications. Inlet design superficial vapor velocity is about 100 ft/sec, with sufficient volume provided to accumulate the entire reactor liquid contents. The lip on the outlet vapor line and the horizontal plate to separate the accumulated liquid are important features to prevent re-entrainment. 

A common scenario involves the pumping, draining, or siphoning of liquid from a tank that has no, or an inadequate, venting capacity and thus cannot allow the entry of air at a rate sufficient to backfill behind the dropping liquid level. 

When the subsurface materials are uniform and isotropic (no gradational changes or confining layers) the airflow pathways are also uniform. The airflow paths developed for an open system and a covered system are shown in Figure 10.5. Selection of covered or uncovered is determined by the air paths necessary to contact the contamination. At some sites, inlet vent wells are installed to ensure air entry at specific locations. 

The new diverter was built according to the description presented in Section 13.1, and it was installed in the extruder. Immediately upon startup of the machine, resin flow from the vent did not occur. Thus, resin that expanded outside of the barrel cylinder at the entry of the vent opening was tucked back into the barrel cylinder. Based on the cost savings for the elimination of the vent flow and the installed cost of the diverter, the payback time was estimated at 18 days. 

Oftentimes, bulk raw materials are stored in storage tanks. Usually these tanks have a vent so that the tank is allowed to breathe. It is important to ensure that the vent opening is protected from precipitation and also to entry by birds or insects into the tank. A mesh screen on a gooseneck vent provides suitable protection. Sometimes the raw material is sensitive to environmental conditions and must be kept under a blanket of inert gas such as nitrogen or maintained at a fixed temperature. Wherever there is a requirement for an inert blanket or temperature control, there should be a device that allows for confirmation the storage tank is maintained under the specified environmental conditions. These conditions should be periodically recorded. 

Water storage tank vent filters must be equipped with a sterilizing air filter in order to prevent the air, which displaces water drawn from the tank, from microbiologically contaminating the water. The filter must be hydrophobic in order to prevent condensation from blinding the filter and preventing air entry or escape from the tank. It also must have a mean porosity of less than 1 pm. 

If, after reading these rules, you conclude that the best place for a balance is in a special room by itself, you are right. Such a room ideally should be windowless, with one separate, shielded entry and filtered, baffled vents. The room should be small, with support beam walls and very heavy benchtops, and should be maintained consistently at 20°C. 

Vent inerts from steam system slowly pressurize to avoid hammer do not overpressure reduced-pressure systems. Purge to less than 1 % O2 by successive pressuring and venting no entries can be permitted unless N2 inlets are blanked. 

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