Gas supply lines

High pressure Low/no flow - chlorine gas supply line for bleaching line A (linked from 5.2) High temperature (linked from 4.3) High pressure - chlorine railcar (linked to 1.5) Potential damage to the vaporizer if isolated from the relief valve on the chlorine railcar (linked to 4.9) Local pressure indication ... 

It is very important that the inert gas be available from a reliable source and that the proper pressure and flow rate are always provided. A low-pressure switch and alarm are sometimes installed in the inert gas supply line to the equipment and piping. The alarm will warn the operator that a problem may be occurring with the inert gas supply. The switch is also sometimes interlocked to open up a valve in piping from a backup inert gas cylinder bank. 

A custom-made Pyrex cell [169] was used to generate selenium hydride. The internal purge gas supply line to the furnace was routed through a stopcock made of Teflon that permitted the operator to select gas flow into either the bottom of the hydride cell or into the furnace, as illustrated in Fig. 12.11. 

Calderbank (Cl) employed a crystal microphone located in the gas supply line near the nozzle tip, which was connected to an oscilloscope through a preamplifier. The photographic comparison of this signal with a constant-frequency (60 cps in this case) test signal, yielded the frequency of bubble formation. 

Ensure there are no leaks in any gas supply lines by bubble-checking all fittings routinely. 

The carbon arc apparatus is shown schematically in Figure 10.2.2. The reaction chamber, which is usually made of stainless steel, is connected to vacuum pumps and a gas supply line through valves. The front of the chamber has an observation window to enable monitoring the arc discharge (19). Electrodes, mounted on the end flanges, are supported horizontally. Alternatively, the electrodes can be fixed vertically (20). The electrodes and chamber walls can be cooled by water-cooling devices if necessary. 

Flame speeds were measured on a nozzle burner. Fuel and air were metered and mixed in the same manner as in the preflame studies. The entire gas supply line and burner assembly were electrically heated to avoid condensation of fuels and additives. The burner was surrounded by a wider tube to prevent ambient air from influencing the flame. The flame speed was determined from the height of the flame cone. 

In the last section, the conical bottom with a cooling jacket, there are shaft support 5 and rotating perforated distribution grate 6, which at the same tume plays the role of support in case the gas supply abruptly ceases. The radiated heat is withdrawn by a heat exchanger, which circulates through jacket 2. The conical lower part of this reactor is filled with head 8, which prevents contact mass from entering the gas supply line. 

Figure Test chamber for the dynamic mechanical moisture sorp-tlon/desorptlon experiments The design of this chamber enables exposure of the sample to a variety of liquid and/or vapor environments. Temperature of the chamber can be controlled by adjusting flow or temperature In the liquid or gas supply lines. Alternatively, the chamber can be jacketed with cooling water or heat tape.

When the fryer oil temperature rises beyond control because of the failure of the high-temperature cutoff device, a certain amount of fire retardant (powder) is discharged on top of the fryer to create a blanket to cut off the oxygen supply to the hot oil. Simultaneously, the main gas supply line gets automatically turned off by a solenoid valve on the gas line set to be shut off in the event the fire retardant is discharged. 

The L79 is easy to build and uses a few common materials in a unique way (see illustration, next page). It consists of a six layered sandwich composed of one PVC end plate, two PC (printed circuit) board elec-trode/gas flow field plates, one 12 PEM MEA (membrane electrode assembly) layer, and 2 rubber gaskets, one of which also acts as a gas supply line. 

Use Template 4 (page 248) to cut the rubber gas supply lines from the /32" thick silicone rubber sheet. Cut the rubber to the correct size and then tape the template to the rubber. Use an Exacto knife or other very sharp cutter to make the gas lines. I used a small Exacto razor knife and found that I had to change blades very frequently - I ran through a whole pack cutting out the gas lines. Cut slowly, and when the template paper starts to bunch up as you are cutting, stop immediately and change the blade. If the template paper rips you will lose the outline which will make it difficult to cut accurately. The process is easy, but as with other operations in this project, it can be tedious. 

Above, cut the gas supply lines out of the rubber with an Exacto knife. 

Coat the gas supply gasket with a thin layer of silicone caulking. Pick up the gasket and position it quickly onto the hydrogen plate before the silicone gets too tacky and sets. All of the gas supply lines must be aligned so that they feed into and out of each cell properly. Check and adjust these quickly before the silicone caulking... 

First, connect the gas supply line from the regulator to the fuel cell entry port barb connector. As a general practice, always have some sort of flashback arrestor between the regulator and the fuel cell stack. This can be a small flashback bubbler that you can construct and install, or you can use a commercial flash arrestor. 

Building Provide fuel gas supply lines with seismic-actuated shutoff valves. 

With such a direct gas displacement pump, the delivery of liquid is virtually pulseless. The liquid pressure is controlled by the pressure controller on the gas supply line. The pressure is limited by the strength of the tank and by the maximum pressure of the gas supply (usually 200 atm, sometimes up to 250 atm). Some commercial direct gas displacement pumps, however, have a maximal pressure of about 100 atm, owing to the safety aspects of working with compressed gases at higher pressures. 

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