Purged line sample

Blowing down Verify flow path before starting the flow. lines for cleaning., Blow (purge) lines to safe location which protects the operator and environment Wear proper personal protective equipment (PPE) Follow proper sampling procedures Use safe blow-down design CCPS G-22 CCPS G-23 CCPS G-29... 

The instrument works in a semi-continuous way. First, the pump purges the sample lines and the measurement cell in order to flush out the old sample and bring in the new one. The valves to and from the measurement cell are then closed and measurement starts the IR source is turned on, the chopper wheel starts rotating and the microphones pick up the photo-acoustic signal. The optical filter wheel positions each of the optical filters in the light path, one after the other, until all filters have been measured. Finally the instrument calculates the concentration of each gas, the results are displayed and the whole procedure starts all over again. 

Purge andTrap Apparatus The purging apparatus uses disposable 15- x 150-mm test tubes. Use ultra-high-purity helium to purge the sample for 15 min at a flow rate of 60 mL/min. Maintain at 100° all lines that the sample vapor passes through in the purge module. 

Select in-line process analyzers to reduce sampling wastes. Use closed-loop (purge style) sampling ports. 

Another critical factor is the choice of an appropriate initial column temperature. In fact, sample vapors can be lost through the septum purge line if the insert is overfilled with sample vapors (either too large injection volume or too small liner volume), leading to nonreproducibility and nonlinearity of peak areas. 

A FLUSH sample (also referred to as purged-line or second-draw) should be taken after letting the water run 5 minutes, until there is a noticeable change in its temperature. This will tell you whether the town water is contaminated before it even gets into your home. 

Slowly crack Valve C to purge the sample valve. When the puige is complete, close Valve C. Caution—Use extreme care to ensure at no flashing of sample occurs in the inlet sampling line and valve system. Always meter at sample purge Valve C, never at sample Valve B. The sample line and valve system should remain at 1379 kPa (200 psi) above the vapor pressure of the product. 

With Valves B and C closed, open sample source Valve A to full open position. Observe the sample source pressure on Gage M, Crack Valve B and fitting to Valve C to purge line. Do not allow Pressure M to drop below sample pressure. Tighten fitting to Valve C and close Valve B. 

If the liquid sample valve is used, the sample cylinder must be pressured up to at least 1100 kPa (160 pag) with an inert gas, sudi as nitrogen or helium (Warning—See Note 1) Also a valve must be installed in the purge line downstream of the liquid sample valve to ensure the butylenes sample in the sampling valve is entirely in the liquid phase prior to injection into the column (Warning— see Note 2). 

Variable-volume vessels should be connected so that the precharge side communicates with line pressure and can be displaced without contaminating the sample. The product side should be connected with minimum dead volume (see Fig. 1(a)). Purge the sample lines with sample gas after connection of the variable-volume vessel. 

Sample Procedure—Sample as in paragraph 5.I.I.I. Use as short a sample line as practical. Purge e sample for 2 min before valving to the sensor. 

In order to ensure accurate and reproducible results, a Vapour Permeation System (VPS) was constructed for the measurement of permeation rates of methane and water vapor in a mixture through PPO membranes and determination of water/methane selectivity. The schematic diagram and the components of the equipment are illustrated in Figure 1. The system is a sweep gas system that is used to measure the permeability of water and methane in a mixture. Using films of proper thickness, sweep gas as well as purging the sample line and sample loop prior to sample collection ensures accurate and reproducible data. 

Sample recirculation lines to minimize line purge... 

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