Valve locations

Gas lift systems aim at lightening the liquid column by injecting gas into it, essentially stimulating natural flow. A gas lift string contains a number of valves located along the string. These valves are only required to kick-off the lifting process under normal... 

Water can also easily be drained from a drain valve located on the bottom. 

Thus the ECCU always operates in complete heat balance at any desired hydrocarbon feed rate and reactor temperature this heat balance is achieved in units such as the one shown in Eigure 1 by varying the catalyst circulation rate. Catalyst flow is controlled by a sHde valve located in the catalyst transfer line from the regenerator to the reactor and in the catalyst return line from the reactor to the regenerator. In some older style units of the Exxon Model IV-type, where catalyst flow is controlled by pressure balance between the reactor and regenerator, the heat-balance control is more often achieved by changing the temperature of the hydrocarbon feed entering the riser. 

Each cylinder discharge line should have a relief valve located upstream of the cooler. Like all reciprocating devices, the piston will continue to increase pressure if flow is blocked. The relief valve assures that nothing is overpressured. It must be located upstream of the coolers as icc can form in the coolers, blocking flow. 

New installations should be provided with only one connection below the liquid level, fully welded up to a first remotely operated fire-safe isolation valve located clear of the tank area. 

Equation 4-331 is valid for a back-flow valve at the bottom of the casing string such as a float collar. It is also valid for a back-flow valve located at the top of the casing string. 

Boiler vents are valves located at the top of a boiler. They are opened to permit air to be bled from a boiler when filling it with water and when initially raising steam. They are also opened during a boiler drain-down to prevent formation of an internal vacuum, which could cause the shell to collapse or other damage to occur. During typical HP boiler warm-up, the boiler vents are kept open until 25 psig steam pressure is registered. 

A type of valve located in the steam line and elsewhere that automatically cuts the boiler in and out, thus providing for online and offline operation. This valve protects the steam system in the event of a loss of pressure from a boiler, caused perhaps by a large steam leak. 

Chlorine flow to environment Internal relief valve sticks open Both internal pressure valves fail open and relief valve opens Operation Potential low chlorine flow to Tower Water Basin -see above Chlorine released to environment - potential personnel injury due to exposure Distinctive odor Pressure check valve located outdoors -unlikely to accumulate significant concentration III Action Item Consider venting relief valve above ground level... 

Where the study required in para. PL-3.6.1 indicates that the Location Class has changed, the sectionalizing valve locations shall be reviewed to determine if access to the valves has been affected. Access routes to the valves shall be evaluated. The effects of evacuating the pipeline in the vicinity of the valves shall be determined. New routes and evacuation and valve location plans shall be developed as required. 

Are the excess flow and/or back pressure check valves located inside the container or at a point outside as close as practicable to where line enters container ... 

As described above, a lockout device can be used as a security measure to prevent unauthorized access to aboveground valves located within chemical processing systems. Valve lockout devices are locks that are specially designed to fit over valves and valve handles to control their ability to be turned or seated. These devices can be used to lock the valve into the desired position. Once the valve is locked, it cannot be turned unless the locking device is unlocked or removed by an authorized individual. 

A major difference between valve-specific lockout devices and the padlocked chain or cable lockouts discussed earlier is that valve-specific lockouts do not need to be secured to an anchoring device in the floor or the piping system. In addition, valve-specific lockouts eliminate potential tripping or access hazards that maybe caused by chains or cable lockouts applied to valves located near walkways or frequently maintained equipment. 

In essence, the disc filter operates in a manner similar to a bottom-feed drum filter. The principal differences to be noted are the compartments which are formed on both faces of vertical discs. These comprise eight or more segments, each of which is connected to the horizontal shaft of the machine. The filtrate and air are drawn through the filter medium, into the drainage system of the segments, and finally through passages in the rotary shaft to a valve located at one or both ends. 

Isolation or emergency shutdown (ESD) valves should be installed to stop fuel flow and the process feed flow into the heater in the event of heater tube rupture. These valves can be automatically actuated by controls or safety interlocks or can be manually operated remotely. Remote actuation can be from a control room console or in the field field actuation stations should be located at least 50 ft (15 m) from the heater. It is also common to provide a manual block valve, located at least 50 ft (15 m) from the heater, on each of the fuel and process feed lines. These should be accessible to operators in the event of an incident involving the heater. 

Fire Protection System System Design System Pressure System Control Valve Locations ... 

Historically, bulk delivery systems have used manual diaphragm valves located at the return end of the global piping system, another carryover from high-purity chemical systems. However, the shear sensitivity of many slurries has fostered the creation of other baek-pressure approaches, including... 

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