Shutoff valves

Piping for snuffing steam injection into a heater firebox is required to help put out a fire if a tube mpture occurs. The snuffing steam isolation valve needs to be located at an accessible spot remote from the heater. Also, a remote fuel shutoff valve should be located adjacent to the snuffing steam valve so that both valves can be accessed quickly in case of fire. 

Remotely Operated Shutoff Valves These should be considered for supply lines and other vulnerable pipelines. Excess flowvalves that close vmen flow exceeds a set amount are possible substitutes, but they are not acceptable to some operators. 

Remote controlled shutoff valves can reduce the severity of incidents. 

A credible spill for Probable Maximum Loss Potential. The minimum spill source is the largest process vessel. The maximum spill size is the combined contents of the largest process vessel, or train of process vessels connected together if not readily isolated. Between these extremes, a credible spill may be estimated after taking into account the presence of remotely operated shutoff valves adequate for an emergency, and automatic dump or flare systems. 

A credible spill for Catastrophic Loss Potential. For a catastrophic loss potential, the spill size should be based on the contents of vessels or connected vessel train. The existence of shutoff valves between vessels should not be considered. In addition, the catastrophic failure of major storage tanks should be considered. Leaks in pipelines carrying materials of concern from large-capacity, off-site, remote storage facilities must be considered. For this purpose, it must be assumed that the pipeline is completely severed and that the spill will run for 30 minutes. 

Pumps, compressors, turbines, drivers, and auxiliary machinery should be designed to provide reliable, rugged performance. Pump selection and performance depend on the capacity required and tlie nature of Uie fluids involved. Remotely controlled power switches and shutoff valves are necessary to control fluid flow during an emergency. The inlets for air compressors should be strategically located to prevent the intake of hazardous materials. 

The number and quality of the safety shut-off valves required is specified in the relevant Standards and Codes of Practice. These are usually electrically operated valves conforming to class 1 or class 2 as defined in BS 5963, Specification for electrically-operated automatic gas shutoff valves (1981). This specifies forward pressures and reverse pressures that the valve must withstand in the closed position together with closing times. 

Nozzles Shutoff Valves Gas injection Equipment Qukkmold-Clamping Systems... 

Propagation Diminish Emergency material transfer Reduce inventories of flammable materials Equipment spacing and layout Nonflammable construction materials Installation of check and emergency shutoff valves... 

Fire fighting equipment should be mounted at heights that are easily accessible by the average person. This includes portable fire extinguishers, hose connections to fire hydrants, access to emergency shutoff valves, emergency stop/ESD push buttons, etc. 

Outside shutoff valves installed in service lines supplying places of public assembly, such as theaters, churches, schools, and hospitals, shall be examined and serviced, including lubrication where necessary, at sufficiently frequent intervals to assure their satisfactory operation. The examination shall determine if the valve is accessible, if the alignment is satisfactory, and if the valve box or vault, if used, contains debris that would interfere with or delay the operation of the valve. Unsatisfactory conditions encountered shall be corrected. Valves in hydrogen service shall be checked and serviced at least annually. 

I-2.2.3 A shutoff valve shall be installed in each takeoff line as near as practicable to the point of takeoff. Blowdown valves shall be installed where necessary for the safe operation of piping, instruments, and equipment. 

Are low-pressure alarms and automatic shutoff valves provided on chlorine/sulfur dioxide feed lines ... 

Are vaporizers provided with automatic gas line shutoff valve, downstream pressure-reducing valve, gas flow control valve, temperature control system and interlocks to shut down gas flow on low vaporizer temperature, and appropriate alarms in a continuously manned control room ... 

Add a manual safety shutoff valve to hydrogen supply line that is easily accessible and prominently labeled for quick manual supply shutoff by operator. 

Standard valve trims are defined by standards such as API 600 and API 602. Elastomer or plastic inserts may be specified to achieve bubble-tight shutoff. Valve manufacturers may be consulted for recommended trims. 

Fig. 7.14. Combination of two-stage pressure regulator (P), shutoff valve (S), flow control valve (F), and rotameter (K). O is the gas outlet.

TANK FILL CAP AND DROP TUBE ADAPTER 0 TANK DROP TUBE 0 SUBMERGED TRANSFER PUMP 0 PIPELINE LEAK DETECTOR 0 EMERGENCY SHUTOFF VALVE 0 SWING JOINT AT A CHANGE OF DIRECTION 0 EXTRACTOR ASSEMBLY [Pg.94]

Basically, no special devices have been developed to handle mobile phases in nano-HPLC. However, our experience dictates that reservoirs small in volume and of high quality glass are preferred for this purpose. Solvent containers should be air tight and free from any contamination. The use of helium gas, through a sparging device, may be beneficial for degasification of solvents in nano-HPLC, which can improve check valve reliabilities, especially at nano flow, and diminish baseline noise in UV detection. Besides, each reservoir should be equipped with a shutoff valve for efficient helium consumption [9]. 

Fuel-handling systems (diaphragms for fuel pumps, see Figure 5.5, fuel hose or fuel hose liner, inject or nozzle seals, needle valves, filter casing gaskets, fuel shutoff valves, carburetor parts)... 

Sample probe assembly with process shutoff valve. 

Figure 1. Schematic diagram of the experimental apparatus. 1. Gas tube, 2. Cool bath (-10 °C), 3. Pump, 4. Relief valve, 5. Check valve, 6. Pressure meter, 7. Shutoff valve, 8. Loop, 9. Water bath (40 °C), 10. Filter 3.2 mm OD x 0.8 mm thick, 0.25 im 11. Reactor, 12. Micrometering valve, 13. and 15. Cold traps, 14. Cooler (at 0 °C), 16. Cooler (at- 60 °C), 17. Flow meter...

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