Purge pumps

Purge pump A with water and pump B with methanol. Dial-a-mix 20% B and equilibrate the column at 1.5mL/min (six column volumes or a stable baseline at 254 nm, about 10 min). (Lab note If the gradient system is a low-pressure mixing system, solvents must be degassed by purging or running under helium.)... 

Disconnect tubing at guard column (if present) or analytical column inlet. Check for flow. Purge pump at high flow rate (10 ml/ min), prime system if necessary. (Prime each pump head separately.) If system has check valve, loosen valve to allow air to escape. If problem persists, flush system with 100% methanol. If problem still persists, contact system manufacturer. 

The automation of the use of disposable cartridges for solid-liquid extraction connected directly with a liquid chromatograph poses major techical problems which are, however, lessened by robotics. Although several partly automatic systems have been described [23-26], there is only one really completely automated system, which was reported recently [27]. It is an automated cartridge exchange module combined with a low-cost purge pump, a solvent selec-... 

Air entrapment within the pump body Large flow and pressure variations Purge pump... 

The vacuum plate drwer is provided as pari of a closed system. The vacuum dryer has a cylindrical housing and is rated for fiill-vacuum operation (typical pressure range 3-27 kPa absolute). The exhaust vapor is evacuated try a vacuum pump and is passed through a condenser for solvent recovery. There is no purge-gas system required for operation under vacuum. Of special note in the vacuum-drying system... 

MISCELLANEOUS TECHNIQUES Freeze-pump-thaw and purging... 

A typical lubrication oil system is shown in Figure 15-1. Oil is stored in a reservoir to feed the pumps and is then cooled, filtered, distributed to the end users, and returned to the reservoir. The reservoir can be heated for startup purposes and is provided with local temperature indication, a high-tempera-ture alarm and high/low level alarm in the control room, a sight glass, and a controlled dry nitrogen purge blanket to minimize moisture intake. 

Beyond the complexities of the dispersive element, the equipment requirements of infrared instrumentation are quite simple. The optical path is normally under a purge of dry nitrogen at atmospheric pressure thus, no complicated vacuum pumps, chambers, or seals are needed. The infrared light source can be cooled by water. No high-voltage connections are required. A variety of detectors are avail-... 

The pump feeding an oil stream to the tubes of a furnace failed. The operator closed the oil valve and intended to open a steam valve to purge the furnace tubes. He opened the wrong valve, there was no flow to the furnace, and the tubes were overheated and collapsed. 

The furnace blower or boiler circulator pump starts up to send heated room air or hot water through the ducts or hot water pipes to the steam radiators, or hot water baseboard units, or individual room air registers located throughout the house. When the thermostat is satisfied that the room temperature has reached the set point, the burner shuts off. In furnaces, the blov er continues to run a few seconds until the air temperature drops to about 90° F, then the blower also shuts off. The furnace blower may come on again before the next burner start-up to purge heat out of the furnace, particularly if the fan has a low turn-on set point. The cycle... 

The stuffing box of the equipment, especially centrifugal pumps, should always be vented before startup. Even though the pump has a flooded suction, it is still possible that air may be trapped in the top of the stuffing box after the initial liquid purge of the pump. 

Effects of performance changes, 201-203 Head curve for single pump, 198 Relations between head, horsepower, capacity and speed, 200 Temperature rise 207-209 Viscosity corrections, 203-207 Purging, flare stack systems, 535 Reciprocating pumps, 215—219 Flow patterns, 219 Specification form, 219 Relief areas, 437 External fires, 451, 453 Sizing, 434, 436... 

Purge Path = PUMP P03 VALVE V20 VALVE V29 VALVE V32)... 

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