Dual Valve Pressure Controllers

Dual Valve Pressure Controllers

Efficient electronic pressure control for closed volumes

Eliminate costly outgassing through continuous bleed valves. Alicat Scientific electronic pressure controllers provide responsive, stable control of absolute, gauge or differential pressures in dead-ended processes.
Brochure Specs ManualOrder Online



Making You Faster

  • 50-100 ms speed of response stills upstream fluctuations.
  • Accessible PID valve tuning for best speed and stability.
  • Custom valve orifice sizing yields full-range stability.
  • PCD3-series remote pressure sense port allows flexible controller placement.
  • Numerous user-selectable engineering units.

Pressure control diagram

Alicat dual valve pressure controller for closed volumes

Alicat dual valve pressure controller for closed volumes



PCD Standard Closed Volume Series

Alicat PCD-series dual-valve pressure controller for closed volumes
Control responsively and stably in closed volumes without wasting costly gases through a continuous bleed valve. The PCD Series incorporates a second, independently-controlled exhaust valve that actuates only when the pressure needs to be reduced, keeping gas venting to an absolute minimum. Available for gauge and absolute pressures up to 2000 psi, or differential pressures up to 150 psid.
PCD Specs


PCRD High-Flow Series

Alicat PCRD-series dual-valve pressure controller for high flow into closed volumes
Maintain pressure stability and accuracy at high flows (50-3000 slpm). Alicat is the world’s only manufacturer of near-frictionless rolamite valves for precise control of high-rate fluid flows. Proprietary orifice patterns enable us to customize a rolamite to satisfy your application and performance requirements. Available for gauge and absolute pressures up to 300 psi, or differential pressures up to 150 psid.
PCRD Specs


PCD3/PCRD3 Remote Sense Port Series

Alicat PCRD3 high-flow dual-valve pressure controller with remote sense port
Unlike the PCD-Series controller, which controls pressure based on conditions inside the instrument, the PCD3-Series controller incorporates a remote sense port that allows a pressure signal to be sent from a point upstream or downstream of the controller. The remote sense port allows users to control pressure in areas that are either hard to reach or in which pressure control equipment cannot be directly installed. This yields faster and more precise targeting of the pressure being controlled, without being affected by flow-induced pressure changes that may occur inside the controller. Available for gauge and absolute pressures up to 300 psi (PCRD3) or 2000 psi (PCD3), or differential pressures up to 150 psid.
PCD3/PCRD3 Specs


PCD-EXTSEN/PCRD-EXTSEN External Sensor Series

Alicat PCD-series dual-valve pressure controller for closed volumes
Whereas the remote sense port of the PCD3 Series uses the internal pressure sensor to read pressures far away, the PCD-EXTSEN Series instead connects to an external pressure transducer via a dedicated connector and cable. The PCD-EXTSEN does not have an internal pressure sensor of its own, instead relying upon the customer-supplied sensor to provide pressure readings. This series is especially useful for vacuum coating processes that employ vacuum gauges.
PCD Specs PCD-EXTSEN Bulletin


PCDS/PCRDS Anti-Corrosive Series

Alicat PCD-series dual-valve pressure controller for closed volumes
Withstand corrosion caused by aggressive gases and liquids such as NH3, H2S and SiH4 with durable 316L stainless steel. Please consult Alicat to confirm compatibility with your corrosive fluids. Available for gauge and absolute pressures up to 300 psi (PCRDS) or 500 psi (PCDS), or differential pressures up to 100 psid.
PCDS/PCRDS Specs


Common Instrument Options

View other available instrument options here.



PC/PCR Single-Valve Series for Flowing Volumes

Alicat PC-series single-valve pressure controller for flowing volumes

Control pressures in flowing volumes with fast control response and rock-solid stability. May be customized with a remote sense port (PC3) or anti-corrosive construction (PCS).

Go to Single-Valve Pressure Controller page.

Download PCD/PCRD SpecsPCDS/PCRDS Specs

Accuracy

  • Standard accuracy (NIST-traceable): +/- 0.25% of the full-scale range
  • Optional high-accuracy calibration: +/- 0.125% of the full-scale range
  • Linear range: 0.5-100% of full scale, 200:1 turndown



Speed of Response

  • Standard response time constant: 50 ms
  • High-flow response time constant: 100 ms (PCRD/PCRD3/PCRDS)
  • *Actual pressure stabilization time also depends upon application setup.



Ranges

  • Gauge ranges (referenced to atmosphere): any full-scale range from 0-2 inH2O(G) to 0-2000 psig (PCD) or 0-300 psig (PCRD). Negative ranges (-15 to 0 psig) also available. *PCDS/PCRDS ranges start at 0-1 psig.
  • Absolute ranges (referenced to vacuum): any full-scale range from 0-15 psia to 0-2000 psia (PCD) or 0-300 psia (PCRD). *PCDS/PCRDS ranges start at 0-30 psia.
  • Differential ranges (referenced to each other): any full-scale range from 0-2 inH2O(D) to 0-150 psid (PCD/PCRD). *PCDS/PCRDS ranges available from 0-1 psid to 0-100 psid. Negative readings indicate an inverse pressure differential.



Pressures

  • Maximum line pressure: 150 psig (differential pressure units only)



Communications

  • 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



Display

  • Simultaneous real-time readings of setpoint and gauge, absolute or differential pressure
  • Standard display: 2.1? monochrome LCD digital display with touch pad interface
  • Optional 2.1? backlit color TFT digital display with touch pad interface



Warranty

  • Limited lifetime warranty
  • Controller unaffected by bumps, humidity or changes in orientation

Ask Alicat: How do you control pressure in a closed system?

Alicat Scientific demonstrates the best way to control pressure in a dead-ended or closed system. Using a dual-valve pressure controller can save you money over a conventional single-valve pressure controller plus bleed valve setup.



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: 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.



Ask Alicat: How tough is an Alicat flow meter? (Drop Test)

We drop an Alicat portable mass flow meter onto unforgiving concrete from increasing heights to test the toughness of this product. After each drop, we compare its measurement to the pre-test baseline.

Gallery

Alicat PCD dual-valve pressure controller

Alicat PCD dual-valve pressure controller

Differential pressure controller for closed volumes (with remote display) by Alicat Scientific. Note the dual pressure sense ports on the front.

Differential pressure controller for closed volumes (with remote display) by Alicat Scientific (PCD-PSID). Note the dual pressure sense ports on the front.

Alicat PCRD high-flow dual-valve pressure controller

Alicat PCRD high-flow dual-valve pressure controller

Alicat PCRD3 high-flow dual-valve pressure controller with remote sense port

Alicat PCRD3 high-flow dual-valve pressure controller with remote sense port (located below the display)

In the Box

Compatible Accessories:

Fluid Dispensing Using Pressure Control

Establish precise control of fluid dispensing by controlling the pressure in the head space above the liquid. The dual-valve pressure controller maintains a constant pressure in the head space with minimal outgassing of excess gases.
See the full app note here.

Fluid Dispensing Using Pressure Control

Fluid dispensing using an Alicat dual-valve pressure controller

Electronic Pressure Control with Remote Sensing

When flow rates entering or leaving a closed volume are high, flow-induced pressure drop can cause inaccurate pressure measurements. The PCD3’s remote sense port accurately monitors the pressure in the closed volume, no matter the flow rate.
See the full app note here.

Electronic Pressure Control with Remote Sensing

Dead-ended pressure control using an Alicat pressure controller with remote sense port