Flow control like you’ve never seen beforeAlicat Scientific proudly introduces the world’s first bidirectional flow controller. Control flows into your process in one direction, and then switch directions. Or control flows into a closed process, and then vent the volume with no need for additional bleed valves.
White Paper Specs Manual
The most versatile flow controller in the world
- 50-100 ms control response for all configurations.
- Measure mass flow and volumetric flow in both directions, plus absolute pressure and temperature.
- Control mass or volumetric flow from a pressurized source or from vacuum.
- Control absolute pressure in a flowing process or closed volume.
- Numerous user-selectable engineering units.
- Includes COMPOSER™ gas composition firmware.
Questions about dual-valve mass flow controllers?
MCD Standard Bidirectional Series
MCRD High-Flow Bidirectional Series
MCDW/MCRDW Low Pressure Drop Series
MCW Specs Go to Whisper page.
MCDS/MCRDS Anti-Corrosive Series
Common Instrument Options
- Precision Dispensing Package, relies on our fast valves to dispense metered amounts of fluid. Includes totalizer with display of elapsed time.
- CSA Class 1 Division 2 (ATEX Zone 2) Area Classification, permits operation in hazardous environments.
- 9-pin or 15-pin D-sub connectors, configured to match any existing pinout.
- Modbus-RTU, available over RS-232 or RS-485. PROFIBUS also available.
- Backlit color display, shines in low lighting environments.
View other available instrument options here.
MC/MCR Single-Valve Series
MC Specs Go to MC page.
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- Standard accuracy (NIST-traceable): +/- (0.8% of the reading + 0.2% of the full-scale negative to positive range)
- Optional high-accuracy calibration: +/- (0.4% of the reading + 0.2% of the full-scale negative to positive range)
- Accuracy specs apply to preloaded and COMPOSER™ gas calibrations.
- Standard response time constant: 50 ms
- High-flow response time constant: 100 ms (MCRD/MCRWD/MCRDS-Series)
- Available ranges: any full-scale range from -0.5 to +0.5 sccm, to -3000 to +3000 slpm
- Standard linear range: -100 to +100% of full scale with -0.5% to +0.5% deadband, 200:1 turndown
- 316L linear range: -1% to +1% deadband, 100:1 turndown (MCDS/MCRDS)
- Maximum line pressure: 145 psig (standard) or 50 psig (MCDW/MCRDW)
- Standard pressure drop: 1-29 psi at full scale, depending upon flow range
- “Whisper” MCDW/MCRDW pressure drop: 0.06-0.69 psi at full scale, depending upon flow range
- Standard communications: RS-232 digital and 0-5 volt analog
- Optional analog communications: 1-5v, 0-10v, 4-20 mA; secondary outputs also available
- Optional communications protocols: RS-485, Modbus RTU (over RS-232 or RS-485), PROFIBUS
- Standard connector: 8-pin mini-DIN
- Optional connector: 9-pin or 15-pin D-sub connectors, configured to match any existing pinout
- Simultaneous real-time readings of setpoint, mass flow, volumetric flow, absolute pressure and temperature
- Standard display: 2.1″ monochrome LCD digital display with touch pad interface
- Optional 2.1″ backlit color TFT digital display with touch pad interface
- Limited lifetime warranty
- Controller unaffected by bumps, humidity or changes in orientation
Gas Select™ 5.0 Gas List for Alicat Mass Flow Meters and ControllersAll Alicat Scientific mass flow meters and mass flow controllers come standard with NIST Ref Prop 9 gas properties data for up to 130 preloaded gas calibrations. Users may switch between selected gases on the fly without any need for recalibration of the mass flow meter or controller. All Gas Select™ calibrations retain the instrument's specified NIST-traceable calibration accuracy. (See individual specifications sheets for details.)
|Pure Gases||Bioreactor Gas Mixes||Pure Corrosives|
|• Acetylene (C2H2)|
• Argon (Ar)
• i-Butane (i-C4H10)
• n-Butane (n-C4H10)
• Carbon dioxide (CO2)
• Carbon monoxide (CO)
• Deuterium (D2)
• Ethane (C2H6)
• Ethylene/Ethene (C2H4)
• Helium (He)
• Hydrogen (H2)
• Krypton (Kr)
• Methane (CH4)
• Neon (Ne)
• Nitrogen (N2)
• Nitrous Oxide (N2O)
• Oxygen (O2)
• Propane (C3H8)
• Sulfur Hexafluoride (SF6)
• Xenon (Xe)
|• 5% CH4 95% CO2|
• 10% CH4 90% CO2
• 15% CH4 85% CO2
• 20% CH4 80% CO2
• 25% CH4 75% CO2
• 30% CH4 70% CO2
• 35% CH4 65% CO2
• 40% CH4 60% CO2
• 45% CH4 55% CO2
• 50% CH4 50% CO2
• 55% CH4 45% CO2
• 60% CH4 40% CO2
• 65% CH4 35% CO2
• 70% CH4 30% CO2
• 75% CH4 25% CO2
• 80% CH4 20% CO2
• 85% CH4 15% CO2
• 90% CH4 10% CO2
• 95% CH4 5% CO2
|*These gases require MS/MCS-Series instruments.
• Ammonia (NH3)
• Butylene (1-Butene)
• Cis-Butene (cis-2-Butene)
• Carbonyl Sulfide (COS)
• Chlorine (Cl2)
• Dimethylether (CH3OCH3)
• Hydrogen Sulfide (H2S)
• Nitrogen Trifluoride (NF3)
• Nitric Oxide (NO)
• Propylene (C3H6)
• Silane (SiH4)
• Sulfur Dioxide (SO2)
|Breathing Gases||Fuel Gas Mixes||Refrigerants|
|• EAN-32 (32% O2+68% N2)|
• EAN-36 (36% O2+64% N2)
• EAN-40 (40% O2+60% N2)
• EA-40 (40% O2+60% Air)
• EA-60 (60% O2+40% Air)
• EA-80 (80% O2+20% Air)
• Heliox-20 (20% O2+80% He)
• Heliox-21 (21% O2+79% He)
• Heliox-30 (30% O2+70% He)
• Heliox-40 (40% O2+60% He)
• Heliox-50 (50% O2+50% He)
• Heliox-60 (60% O2+40% He)
• Heliox-80 (80% O2+20% He)
• Heliox-99 (99% O2+1% He)
• Metabolic Exhalant (16% O2+78.04% N2+5% CO2+0.96% Ar)
|• Coal Gas 50% H2+35% CH4+10% CO+5% C2H4|
• Endothermic Gas 75% H2+25% N2
• HHO 66.67% H2+33.33% O2
• LPG HD-5 96.1% C3H8+1.5% C2H6+0.4% C3H6+1.9% n-C4H10
• LPG HD-10 85% C3H8+10% C3H6+ 5% n-C4H10
• Nat Gas 93% CH4+3% C2H6+1% C3H8+2% N2+1% CO2
• Nat Gas 95% CH4+3% C2H6+1% N2+ 1% CO2
• Nat Gas 95.2% CH4+2.5% C2H6+0.2% C3H8+0.1% C4H10+1.3% N2+0.7% CO2
• Syn Gas 40% H2+29% CO+20% CO2+11% CH4
• Syn Gas 64% H2+28% CO+1% CO2+7% CH4
• Syn Gas 70% H2+4% CO+25% CO2+1% CH4
• Syn Gas 83% H2+14% CO+3% CH4
|*These gases require MS/MCS-Series instruments.
• R-11 Trichlorofluoromethane (CCl3F)
• R-14 Tetrafluoromethane (CF4)
• R-22 Difluoromonochloromethane (CHClF2)
• R-23 Trifluoromethane (CHF3)
• R-32 Difluoromethane (CH2F2)
• R-115 Chloropentafluoroethane (C2ClF5)
• R-116 Hexafluoroethane (C2F6)
• R-124 Chlorotetrafluoroethane (C2HClF4)
• R-125 Pentafluoroethane (C2HF5)
• R-134A Tetrafluoroethane (CH2FCF3)
• R-142B Chlorodifluoroethane (CH3CClF2)
• R-143A Trifluoroethane (C2H3F3)
• R-152A Difluoroethane (C2H4F2)
• RC-318 Octafluorocyclobutane (C4F8)
• R-404A (44% R-125+4% R-134A+52% R-143A)
• R-407C (22% R-32+25% R-125+52% R-134A)
• R-410A (50% R-32+50% R-125)
• R-507A (50% R-125+50% R-143A)
|Chromatography Gases||Oxygen Concentrator Gas Mixes|
|• P-5 (5% CH4+95% Ar)|
• P-10 (10% CH4+90% Ar)
|• 89% O2+7% N2+4% Ar|
• 93% O2+3% N2+4% Ar
• 95% O2+1% N2+4% Ar
|Welding Gases||Stack/Flue Gas Mixes||Laser Gas Mixes|
|• C-2 (2% CO2+98% Ar)|
• C-8 (8% CO2+92% Ar)
• C-10 (10% CO2+90% Ar)
• C-15 (15% CO2+85% Ar)
• C-20 (20% CO2+80% Ar)
• C-25 (25% CO2+75% Ar)
• C-50 (50% CO2+50% Ar)
• C-75 (75% CO2+25% Ar)
• He-25 (25% He+75% Ar)
• He-50 (50% He+50% Ar)
• He-75 (75% He+25% Ar)
• He-90 (90% He+10% Ar)
• A1025 (90% He+7.5% Ar+2.5% CO2)
• Stargon CS (90% Ar+8% CO2+2% O2)
|• 2.5% O2+10.8% CO2+85.7% N2+1% Ar|
• 2.9% O2+14% CO2+82.1% N2+1% Ar
• 3.7% O2+15% CO2+80.3% N2+1% Ar
• 7% O2+12% CO2+80% N2+1% Ar
• 10% O2+9.5% CO2+79.5% N2+1% Ar
• 13% O2+7% CO2+79% N2+1% Ar
|• 4.5% CO2+13.5% N2+82% He
• 6% CO2+14% N2+80% He
• 7% CO2+14% N2+79% He
• 9% CO2+15% N2+76% He
• 9.4% CO2+19.25% N2+71.35% He
• 9% Ne+91% He
Ask Alicat: How do you control flow in TWO directions?
Alicat Scientific introduces the world’s first bidirectional flow and pressure controller: the dual-valve MCD. Control mass flow, volumetric flow and pressure in both directions with stand-alone control and 30 on-board gas calibrations over a 200:1 turndown range. Or control pressure or flow into a closed process, and vent the volume with no need for additional bleed valves or continuous outgassing. The MCD is the single most versatile flow controller in the world.
Ask Alicat: How fast is an Alicat mass flow controller?
Flow stability and accuracy depend on fast control response, and Alicat is the fastest. This video demonstrates 0 to 100% setpoint changes with settling times of less than 30 ms and control T/C of only 7.4 ms.
Alicat Turndown Ratio for Mass Flow
Alicat demonstrates an incredible 5000:1 turndown ratio, commanding a 5 slpm (5000 sccm) mass flow controller to control down to 1 sccm!
The Fastest Flow Controller Company in the World
How can Alicat claim to be the fastest flow controller company in the world? This video introduces you to some of the many ways that Alicat mass flow and pressure instruments can make you more efficient, saving you time and money.
Ask Alicat: What Is Pressure Drop?
Pressure drop is the amount of line pressure that is permanently lost as gas passes through an instrument in a gas line. Alicat Scientific demonstrates the importance of pressure drop for gas flow processes and shows how you can greatly reduce pressure drop by using its Whisper Series of mass flow instruments.
In the Box
- MCD-Series bidirectional mass flow controller (power supply sold separately)
- NIST-traceable calibration certificate
- Alicat operating manual
Bidirectional Flow Control for Remote Air Sampling and Calibration
Alicat’s MCD Series bidirectional mass flow controller lets you sample ambient air in one direction and then periodically calibrate your gas analyzer in the other direction without disconnecting any part of the system. This allows for easier operation and calibration of remote air monitoring stations.
See the full app note here.