Series 7950 Gas Proportioner

The gas proportioner meters the flow of each of two gases and mixes them thouroughly in a special mixing tube to produce homogeneous two-component mixtures. Concentration accuracies of 10% of component value are maintained with a standard unit using typical calibration curves. (In a desired mixture of 1% of gas A and 99% of gas B, a concentration between 0.9% and 1.1% is maintained.) Individual units can be calibrated for non-corrosive gases to attain an accuracy of 5% of the component value. Individual calibration curves are supplied with these specially calibrated units.

The gas proportioners are back pressure compensated to the readings on the tubes are accurate regardless of the back pressure, so long as the inlet pressures are maintained at the levels for which the tubes were calibrated.

The unit is recommended for 50 psig pressure but can be used at any pressure between 10 and 200 psi.

The control valves are installed at the outlets. The tubes have a single glass float. Typical calibration curves for air at 50 psig using the glass float as provided. Typical maximum flow of air under these conditions is as follows:

7920-1--117 ccm
7920-2--192 ccm
7920-3--816 ccm
7920-4--1780 ccm
7920-5--5376 ccm
7920-6--8043 ccm
7920-7--18081 ccm
7920-8--52332 ccm
7920-10--218 ccm

The proportioners are available in both aluminum and stainless steel construction. When ordering a gas proportioner, specify the composition of the desired mixture, the gases, the discharge rate, and inlet pressure in addition to the model number.

Ordering Information

Model	Material	Valve	Connections
7951	Aluminum	Standard	1/8" NPT female
7951H	Aluminum	Standard	1/4" hose barb
7951T	Aluminum	Standard	1/4" compression
7952	Aluminum	High Accuracy	1/8" NPT female
7952H	Aluminum	High Accuracy	1/4" hose barb
7952T	Aluminum	High Accuracy	1/4" compression
7953	Stainless Steel	Standard	1/8" NPT female
7953H	Stainless Steel	Standard	1/4" hose barb
7953T	Stainless Steel	Standard	1/4" compression
7954	Stainless Steel	High Accuracy	1/8" NPT female
7954H	Stainless Steel	High Accuracy	1/4" hose barb
7954T	Stainless Steel	High Accuracy	1/4" compression

All models include a baseplate, mixing tube and two flowmeter tubes of your choice selected from the Table below. *If unsure of correct tubes, provide the composition range of intended mixtures, total outlet flow and operating inlet pressure. We will select the tubes.

Tube Table

Model	Typical Flow Range^*
Model	Float	Air scc/min.	Water cc./min.
7920-1	Glass Stainless Steel	3-56 11-158	0.04-0.66 0.12-3.18
7920-2	Glass Stainless Steel	6-91 16-271	0.08-1.0 0.17-5.5
7920-3	Glass Stainless Steel	22-388 63-845	0.24-7.8 0.68-17
7920-4	Glass Stainless Steel	64-847 217-1707	1-17 2-46
7920-5	Glass Stainless Steel	550-2560 1070-5080	6-54 21-135
7920-6	Glass Stainless Steel	610-3830 1330-7670	9-89 30-217
7920-7	Glass Stainless Steel	820-8610 2090-16580	14-200 53-482
7920-8	Glass Stainless Steel	2220-24920 4190-45940	47-568 102-1319
7920-10	Glass	0.1-100	0.003-1.4

Selected Correction Factors flow=air flow x correction factor
Gas	Correction factors
Air	1.00
Acetylene	1.054
Ammonia	1.304
Argon	0.851
n-Butane	0.706
Carbon Dioxide	0.811
Carbon Monoxide	1.017
Ethane	0.981
Ethylene	1.016
Helium	2.689
Hydrogen	3.810
Methane	1.343
Nitrogen	1.017
Nitrous Oxide	0.811
Oxygen	0.951
Propane	0.810