PROPORTIONAL VALVE PDF



Proportional Valve Pdf

Proportional and Servo Valve Technology. This unit is an electro-hydraulic, proportional, screw in cartridge style, pilot operated, sliding spool type, high pressure reducing and relieving control valve., Proportional valve technologies are available using a variety of operating methods. Operators may include the following: Direct-acting proportional coil solenoids, which act directly on pistons or spools to adjust valve open or closed positions, based on varying voltage across the coil.

Proportion-Air Global Leader in Electronic Pressure

Proportional Valves Parker NA. B-4 Eaton Hydraulic Screw-in Cartridge Valves (SiCV) E-VLSC-MC001-E6—January 2018 www.eaton.com B 1 2 1 (Out) 2 (In) Functional symbol Proportional valves Valve locator/section contents EPV16A EPV16B Note: Proportional valve solenoid coils and electronic valve drivers are covered in section C of this, PVG 128 and 256 Proportional Valve PVE-EX Ex db for PVG Proportional Valves: BC00000393: PDF: 0102.

Parker offers a range of proportional valves employing powerful voice-coil valve technology, which allows higher flows from smaller valves. These valves provide a high response and are offered with or without on-board control electronics. Catalog HY14-2550/US Proportional Directional Control Valves A138 Parker Hannifin Corporation Hydr alv Division Elyr A Series D1FP A D F Directional Control Valve …

non-feedback type proportional valves. Two-stage proportional directional control valves in which the main-stage spool is positioned according to the output from an integrally mounted proportional, solenoid-operated , pressure-reducing valve. Direction of main-spool travel depends upon which of the two solenoids of the pilot valve is energized that of the standard valve. Additionally, both of these valve types can be supplied with or without an integral amplifier built directly onto the valve. General description KBFD/TG4V-5 A range of proportional directional and throttle valves with integral control electronics . Factory-set adjustments of

Oct 04, 2018В В· Kelly Pneumatics, Inc. offers a high volume flow Midsize Proportional Valve utilizing award winning design. This non-spool valve architecture employing one moving part ensures virtually frictionless performance and longevity tested at over 100 million cycles. 4 KUDSR Proportional flow control valve Functional description Functional description General The proportional flow control valve is a direct operated screw-in cartridge valve in spool design with integrated pressure compensator. It regulates the flow proportionally to the input signal in a stepless form from port P to A. Any

4 KUDSR Proportional flow control valve Functional description Functional description General The proportional flow control valve is a direct operated screw-in cartridge valve in spool design with integrated pressure compensator. It regulates the flow proportionally to the input signal in a stepless form from port P to A. Any PROPORTIONAL ELECTRO-HYDRAULIC RELIEF AND FLOW CONTROL VALVE FEATURES: This relief and flow control valve is an energy-saving valve that supplies the minimum pressure and flow necessary for actuator drive. Since this valve controls the pump pressure by following the load pressure

Special cavity, slip-in style flange retained, direct acting proportional, pressure reducing/relieving valve. OPERATION The IP-DAR-250 generates a variable pressure in response to a PWM (Pulse Width Modulated) current signal. With no current applied to the proportional solenoid, the inlet port 2 (P) is blocked and the regulated port 3 (C) is Introduction Application Note – Proportional Valve Technology – 1.10 Seite 7 von 18 2.3 Proportional Valve working principles 3. For the proportional directional control valve, the solenoid coil directly operates the internal piston.

The two purposes of a blocking valve in a proportional valve system; The setting and troubleshooting of the hydraulic power supply components; the pressure compensating pump, relief valve, accumulator, and automatic dump valve. The function of the three electrical signals fed into a proportional valve amplifier. Proportional valve technologies are available using a variety of operating methods. Operators may include the following: Direct-acting proportional coil solenoids, which act directly on pistons or spools to adjust valve open or closed positions, based on varying voltage across the coil

Because the proportional valve is used in many different applications and under different operating conditions, it is the sole responsibility of the manufacturer to ensure that all performance, safety and warning requirements of the application is met in his selection of products and complies with relevant Three port electro-proportional reducing/reducing valves – PRDP and PRDN The PRDP, standard reducing/relieving valve, and the PRDN, inverse function reducing/relieving valve, are direct acting elec-tro-proportional cartridges that reduce a high inlet pressure at port 2 …

K(B)FD/TG4V-5 12 Series Proportional Directional Valves. GoTo Proportional Valves – Ships in 10 business days. USA. Select your location. 4WRA & 4WRAE – Proportional directional valve, direct operated without electrical feedback. 4WRA & 4WRAE – Proportional directional valve, direct operated without electrical feedback ., GoTo Proportional Valves – Ships in 10 business days. USA. Select your location. 4WRA & 4WRAE – Proportional directional valve, direct operated without electrical feedback. 4WRA & 4WRAE – Proportional directional valve, direct operated without electrical feedback ..

Hydraulic Proportional Closed Loop System Design

proportional valve pdf

Proportional Valves Bosch Rexroth USA. Parker’s D*FW series direct operated proportional directional control solenoid valves are universally applicable and are available in sizes NG6 (CETOP 3) and NG10 (CETOP 5) Proportional Directional Control Valve - D1FW/D3FW Series Email Print, Parker’s D*FW series direct operated proportional directional control solenoid valves are universally applicable and are available in sizes NG6 (CETOP 3) and NG10 (CETOP 5) Proportional Directional Control Valve - D1FW/D3FW Series Email Print.

Proportional Pressure Reducing Valve

proportional valve pdf

www.imdl.gatech.edu. Mar 22, 2017 · Hydraulics, proportional valve, open loop system, servo valve, closed loop control From the content: 0:00 Introduction 0:34 Proportional way valve … https://en.wikipedia.org/wiki/Proportioning_valve Special cavity, slip-in style flange retained, direct acting proportional, pressure reducing/relieving valve. OPERATION The IP-DAR-250 generates a variable pressure in response to a PWM (Pulse Width Modulated) current signal. With no current applied to the proportional solenoid, the inlet port 2 (P) is blocked and the regulated port 3 (C) is.

proportional valve pdf


Parker offers a range of proportional valves employing powerful voice-coil valve technology, which allows higher flows from smaller valves. These valves provide a high response and are offered with or without on-board control electronics. Clippard EVP Series Proportional Control Valves combine the features of the well-known and trusted original EV Series valves with the additional capability of proportional control. The EVP Series provides air or gas flow control, and varies the output flow based on the current input to the solenoid. The consistent gain of this valve provides a high degree of control for many applications.

The proportional directional control valve in fig. 1.4 assumes the function of the flow control and the directional control valve in fig 1.3. The use of proportional technology saves one valve. The proportional valves are controlled by means of an electrical control system via an electrical signal, whereby it is possible, during operation, Servo valves are a close relative of the proportional valve and are based on an electrical torque motor which produces a small deflection proportional to the electrical current through its coil. They commonly use feedback between the main and pilot spools to give precise control. A typical device is shown in Figure 4.40.This consists of a small pilot spool connected directly to the torque motor.

Servo valves are a close relative of the proportional valve and are based on an electrical torque motor which produces a small deflection proportional to the electrical current through its coil. They commonly use feedback between the main and pilot spools to give precise control. A typical device is shown in Figure 4.40.This consists of a small pilot spool connected directly to the torque motor. that of the standard valve. Additionally, both of these valve types can be supplied with or without an integral amplifier built directly onto the valve. General description KBFD/TG4V-5 A range of proportional directional and throttle valves with integral control electronics . Factory-set adjustments of

• External cartridge valve connecting LS pressure or main pressure to tank PVG 120 – pump disconnect / block for variable pumps: • PVPE, full flow dump for the PVG 120 • External cartridge valve connecting LS pressure to tank Service Manual PVG 120 Proportional Valve Group Safety in application 520L0247 • … PVG 128 and 256 Proportional Valve PVE-EX Ex db for PVG Proportional Valves: BC00000393: PDF: 0102

ASCO has emerged as a leader with the most complete line of Proportional Valve Products that provide fast response and consistent control of pressure and flow Many industrial applications such as web tensioning, ultrasonic welding, positioning, fluid coating, and laser cutting demand accurate control of pressure and flow. ASCO has emerged as a leader with the most complete line of Proportional Valve Products that provide fast response and consistent control of pressure and flow Many industrial applications such as web tensioning, ultrasonic welding, positioning, fluid coating, and laser cutting demand accurate control of pressure and flow.

Nominal valve drop ∆p = 10 bar (145 psi) You must estimate pressure drops, psystem – p load = pvalve To find a spool, solve for “Nominal flow” Estimate required valve pressure drop Qn = c A ∆Pn Flow Rating of Proportional Valves Qreq = c A ∆Preal c = orifice flow co-efficient A = Area of orifice PROPORTIONAL ELECTRO-HYDRAULIC RELIEF AND FLOW CONTROL VALVE FEATURES: This relief and flow control valve is an energy-saving valve that supplies the minimum pressure and flow necessary for actuator drive. Since this valve controls the pump pressure by following the load pressure

Proportion-Air is a US-based manufacturer with a global reputation for quality and excellence in industrial automation. We seek to understand every customer’s application and build a product tailored to the specific process.We build our products to your specifications whether you need one device or thousands. Offering free application and technical support, we strive to quote within 6 hours As a result, servo valves are always much more expensive. A proportional control valve system can be used to improve control of most machines without the high price tag of servo control systems. Quality Hydraulics & Pneumatics, Inc. offers design, products and systems for all three types: directional, proportional and servo valve control systems.

Proportional Valve an overview ScienceDirect Topics

proportional valve pdf

Proportional flow control valve with integrated pressure. Increasing proportional valve capabilities with Industry 4.0. Bosch Rexroth employs highly advanced microelectronics to increase the capability of hydraulic servo and directional valves. Easily integrated into machinery concepts they offer excellent energy efficiency, optimal power, and Bosch Rexroth quality., ASCO has emerged as a leader with the most complete line of Proportional Valve Products that provide fast response and consistent control of pressure and flow Many industrial applications such as web tensioning, ultrasonic welding, positioning, fluid coating, and laser cutting demand accurate control of pressure and flow..

Proportional hydraulics proportional valve servo valve

Proportional Solenoid Valves ASCO. GoTo Proportional Valves – Ships in 10 business days. USA. Select your location. 4WRA & 4WRAE – Proportional directional valve, direct operated without electrical feedback. 4WRA & 4WRAE – Proportional directional valve, direct operated without electrical feedback ., Proportion-Air is a US-based manufacturer with a global reputation for quality and excellence in industrial automation. We seek to understand every customer’s application and build a product tailored to the specific process.We build our products to your specifications whether you need one device or thousands. Offering free application and technical support, we strive to quote within 6 hours.

4 KUDSR Proportional flow control valve Functional description Functional description General The proportional flow control valve is a direct operated screw-in cartridge valve in spool design with integrated pressure compensator. It regulates the flow proportionally to the input signal in a stepless form from port P to A. Any Proportional Valve without Feedback 4WRA - Direct Operated Estimate Pressure Drop Required Across Valve (System Pressure - Load Pressure - Other Pressure Drops) Find Target Flow AtFind Target Flow At ~90% Command, Compare90% Command, Compare pcurve withabovewith above Avoid High Valve p (Above 50% System Pressure Dropped in Valve Can Cause Rotational Forces on Proportional Spool

proportional valve solenoidoperatesoffofa variable current signal, usually 2.7 amps maximum. The larger NG10valvehasacurrent rangeof0-3.7amps. By varying the current to the valve coil the position of the spool changes. With no enable signal or power supply voltage to the amplifier, then no current will be applied to the valve coil and the valve 2/2-way proportional valves with piezo technology Flow control The 2/2-way proportional valve controls, for example, the precise supply and metering of oxygen in oxygen therapy devices during inhalation. In combination with a flow sensor and control elec-tronics it turns into a propor-tional flow control valve. With a flow sensor and control

HYDAC proportional valves are electronically actuated valves for which the output value - pressure or flow - is changed at the same ratio as the inlet value. Control electronics and proportionally designed solenoids are required for actuation. 2 PRV Series Proportional Safety Relief Valves Features All 316L stainless steel wetted metal components Five set spring pressure ranges Factory-set, tested, locked, and tagged with the set pressure CE-marked in accordance with the Pressure Equipment Directive as a safety valve according to ISO-4126-1 Available integral end connections—1/4 and 3/4 in. female

The proportional directional control valve in fig. 1.4 assumes the function of the flow control and the directional control valve in fig. 1.3. The use of proportional technology saves one valve. The proportional valves are controlled by means of an electrical control system via an electrical signal, whereby it is possible, during operation, Catalog HY14-2550/US Proportional Directional Control Valves A138 Parker Hannifin Corporation Hydr alv Division Elyr A Series D1FP A D F Directional Control Valve …

What's the Difference Between a Servovalve and a Proportional Valve? What's the Difference Between a Servovalve and a Proportional Valve? By Jack L. Johnson, P. E. Aug 08, 2012. Download this article in .PDF format. In nearly every industrial training program that I conduct, someone asks me to explain the differences between servo and Introduction Application Note – Proportional Valve Technology – 1.10 Seite 7 von 18 2.3 Proportional Valve working principles 3. For the proportional directional control valve, the solenoid coil directly operates the internal piston.

non-feedback type proportional valves. Two-stage proportional directional control valves in which the main-stage spool is positioned according to the output from an integrally mounted proportional, solenoid-operated , pressure-reducing valve. Direction of main-spool travel depends upon which of the two solenoids of the pilot valve is energized Parker’s D*FW series direct operated proportional directional control solenoid valves are universally applicable and are available in sizes NG6 (CETOP 3) and NG10 (CETOP 5) Proportional Directional Control Valve - D1FW/D3FW Series Email Print

Catalog HY14-2550/US Proportional Directional Control Valves A138 Parker Hannifin Corporation Hydr alv Division Elyr A Series D1FP A D F Directional Control Valve … Special cavity, slip-in style flange retained, direct acting proportional, pressure reducing/relieving valve. OPERATION The IP-DAR-250 generates a variable pressure in response to a PWM (Pulse Width Modulated) current signal. With no current applied to the proportional solenoid, the inlet port 2 (P) is blocked and the regulated port 3 (C) is

miniature proportional valve provides precise flow control of gas in proportion to input current. The valve can be controlled with either DC current . or pulse width modulation along with closed loop feedback to deliver optimal system performance. Together with its ability to provide precise control over . The proportional directional control valve in fig. 1.4 assumes the function of the flow control and the directional control valve in fig. 1.3. The use of proportional technology saves one valve. The proportional valves are controlled by means of an electrical control system via an electrical signal, whereby it is possible, during operation,

Proportional Valve without Feedback 4WRA - Direct Operated Estimate Pressure Drop Required Across Valve (System Pressure - Load Pressure - Other Pressure Drops) Find Target Flow AtFind Target Flow At ~90% Command, Compare90% Command, Compare pcurve withabovewith above Avoid High Valve p (Above 50% System Pressure Dropped in Valve Can Cause Rotational Forces on Proportional Spool HYDAC proportional valves are electronically actuated valves for which the output value - pressure or flow - is changed at the same ratio as the inlet value. Control electronics and proportionally designed solenoids are required for actuation.

Parker offers a range of proportional valves employing powerful voice-coil valve technology, which allows higher flows from smaller valves. These valves provide a high response and are offered with or without on-board control electronics. Special cavity, slip-in style flange retained, direct acting proportional, pressure reducing/relieving valve. OPERATION The IP-DAR-250 generates a variable pressure in response to a PWM (Pulse Width Modulated) current signal. With no current applied to the proportional solenoid, the inlet port 2 (P) is blocked and the regulated port 3 (C) is

that of the standard valve. Additionally, both of these valve types can be supplied with or without an integral amplifier built directly onto the valve. General description KBFD/TG4V-5 A range of proportional directional and throttle valves with integral control electronics . Factory-set adjustments of ASCO has emerged as a leader with the most complete line of Proportional Valve Products that provide fast response and consistent control of pressure and flow Many industrial applications such as web tensioning, ultrasonic welding, positioning, fluid coating, and laser cutting demand accurate control of pressure and flow.

Proportional Valve without Feedback 4WRA - Direct Operated Estimate Pressure Drop Required Across Valve (System Pressure - Load Pressure - Other Pressure Drops) Find Target Flow AtFind Target Flow At ~90% Command, Compare90% Command, Compare pcurve withabovewith above Avoid High Valve p (Above 50% System Pressure Dropped in Valve Can Cause Rotational Forces on Proportional Spool HYDAC proportional valves are electronically actuated valves for which the output value - pressure or flow - is changed at the same ratio as the inlet value. Control electronics and proportionally designed solenoids are required for actuation.

Nov 01, 2018В В· This valve dynamically compensates for varying inlet pressures, while still maintaining consistent output flow characteristics. Effective in applications with either fluctuating or oscillating control pressures, the Pressure Compensating Proportional Valve can maintain flow rates with input pressures reaching 250 PSIG. R3A series valve shown. Lock nut maintains cap position, ensuring set pressure adjustment Applications R series relief valves are proportional relief valves that open gradually as the pressure increases. Consequently, they do not have a capacity rating at a given pressure rise (accumulation), and they are not certified to ASME or any other codes.

Proportional servo valves Bosch Rexroth USA

proportional valve pdf

Proportional servo valves Bosch Rexroth USA. Oct 04, 2018В В· Kelly Pneumatics, Inc. offers a high volume flow Midsize Proportional Valve utilizing award winning design. This non-spool valve architecture employing one moving part ensures virtually frictionless performance and longevity tested at over 100 million cycles., 2/2-way proportional valves with piezo technology Flow control The 2/2-way proportional valve controls, for example, the precise supply and metering of oxygen in oxygen therapy devices during inhalation. In combination with a flow sensor and control elec-tronics it turns into a propor-tional flow control valve. With a flow sensor and control.

Proportional Valves Bucher Hydraulics

proportional valve pdf

PROPORTIONAL VALVE SYSTEMS TROUBLESHOOTING GPM. B-4 Eaton Hydraulic Screw-in Cartridge Valves (SiCV) E-VLSC-MC001-E6—January 2018 www.eaton.com B 1 2 1 (Out) 2 (In) Functional symbol Proportional valves Valve locator/section contents EPV16A EPV16B Note: Proportional valve solenoid coils and electronic valve drivers are covered in section C of this https://en.wikipedia.org/wiki/Proportioning_valve 2 PRV Series Proportional Safety Relief Valves Features All 316L stainless steel wetted metal components Five set spring pressure ranges Factory-set, tested, locked, and tagged with the set pressure CE-marked in accordance with the Pressure Equipment Directive as a safety valve according to ISO-4126-1 Available integral end connections—1/4 and 3/4 in. female.

proportional valve pdf

  • Proportional Directional Control Valve D1FW/D3FW Series
  • Proportional Solenoid Valves ASCO

  • PVG 32 Proportional Valve Service Parts Manual Sectional drawing 1. Pressure relief valve 2. Pressure reduction valve for pilot supply 3. Pressure gauge connection 4. Plug, open center 5. Oriп¬Ѓ ce, closed center 6. Pressure adjustment spool 7. Plug, closed center 8. LS-connection 9. LS-signal 10. Shuttle valve 11. Main spool 12. LS-pressure 2/2-way proportional valves with piezo technology Flow control The 2/2-way proportional valve controls, for example, the precise supply and metering of oxygen in oxygen therapy devices during inhalation. In combination with a flow sensor and control elec-tronics it turns into a propor-tional flow control valve. With a flow sensor and control

    Nominal valve drop ∆p = 10 bar (145 psi) You must estimate pressure drops, psystem – p load = pvalve To find a spool, solve for “Nominal flow” Estimate required valve pressure drop Qn = c A ∆Pn Flow Rating of Proportional Valves Qreq = c A ∆Preal c = orifice flow co-efficient A = Area of orifice ASCO has emerged as a leader with the most complete line of Proportional Valve Products that provide fast response and consistent control of pressure and flow Many industrial applications such as web tensioning, ultrasonic welding, positioning, fluid coating, and laser cutting demand accurate control of pressure and flow.

    non-feedback type proportional valves. Two-stage proportional directional control valves in which the main-stage spool is positioned according to the output from an integrally mounted proportional, solenoid-operated , pressure-reducing valve. Direction of main-spool travel depends upon which of the two solenoids of the pilot valve is energized • External cartridge valve connecting LS pressure or main pressure to tank PVG 120 – pump disconnect / block for variable pumps: • PVPE, full flow dump for the PVG 120 • External cartridge valve connecting LS pressure to tank Service Manual PVG 120 Proportional Valve Group Safety in application 520L0247 • …

    The proportional directional control valve in fig. 1.4 assumes the function of the flow control and the directional control valve in fig 1.3. The use of proportional technology saves one valve. The proportional valves are controlled by means of an electrical control system via an electrical signal, whereby it is possible, during operation, Increasing proportional valve capabilities with Industry 4.0. Bosch Rexroth employs highly advanced microelectronics to increase the capability of hydraulic servo and directional valves. Easily integrated into machinery concepts they offer excellent energy efficiency, optimal power, and Bosch Rexroth quality.

    Because the proportional valve is used in many different applications and under different operating conditions, it is the sole responsibility of the manufacturer to ensure that all performance, safety and warning requirements of the application is met in his selection of products and complies with relevant that of the standard valve. Additionally, both of these valve types can be supplied with or without an integral amplifier built directly onto the valve. General description KBFD/TG4V-5 A range of proportional directional and throttle valves with integral control electronics . Factory-set adjustments of

    Proportional and Servo Valve Technology 8• Fl uid Power Journal March/April 2003 The ability to achieve automated stepless control of pressure and flow rate in fluid power systems has undergone major development in the past twenty-five years. Electrohydraulic servo valves were invented in the late PDE3 - Proportional pressure relief valve, direct operated. The PDE3 valve is a direct operated pressure control proportional valve CETOP03, with mounting interface in compliance with ISO 4401 standards.. It is suitable to pilot two-stage valves, or for pressure control in hydraulic circuits.

    4 KUDSR Proportional flow control valve Functional description Functional description General The proportional flow control valve is a direct operated screw-in cartridge valve in spool design with integrated pressure compensator. It regulates the flow proportionally to the input signal in a stepless form from port P to A. Any PVG 128 and 256 Proportional Valve PVE-EX Ex db for PVG Proportional Valves: BC00000393: PDF: 0102

    Browse Proportional Valves products. Emerson is where technology and engineering come together to create solutions for the benefit of our customers, driven without compromise for a world in action. B-4 Eaton Hydraulic Screw-in Cartridge Valves (SiCV) E-VLSC-MC001-E6—January 2018 www.eaton.com B 1 2 1 (Out) 2 (In) Functional symbol Proportional valves Valve locator/section contents EPV16A EPV16B Note: Proportional valve solenoid coils and electronic valve drivers are covered in section C of this

    HYDAC proportional valves are electronically actuated valves for which the output value - pressure or flow - is changed at the same ratio as the inlet value. Control electronics and proportionally designed solenoids are required for actuation. 4 KUDSR Proportional flow control valve Functional description Functional description General The proportional flow control valve is a direct operated screw-in cartridge valve in spool design with integrated pressure compensator. It regulates the flow proportionally to the input signal in a stepless form from port P to A. Any

    Clippard EVP Series Proportional Control Valves combine the features of the well-known and trusted original EV Series valves with the additional capability of proportional control. The EVP Series provides air or gas flow control, and varies the output flow based on the current input to the solenoid. The consistent gain of this valve provides a high degree of control for many applications. ASCO has emerged as a leader with the most complete line of Proportional Valve Products that provide fast response and consistent control of pressure and flow Many industrial applications such as web tensioning, ultrasonic welding, positioning, fluid coating, and laser cutting demand accurate control of pressure and flow.

    Proportional valve technologies are available using a variety of operating methods. Operators may include the following: Direct-acting proportional coil solenoids, which act directly on pistons or spools to adjust valve open or closed positions, based on varying voltage across the coil B-4 Eaton Hydraulic Screw-in Cartridge Valves (SiCV) E-VLSC-MC001-E6—January 2018 www.eaton.com B 1 2 1 (Out) 2 (In) Functional symbol Proportional valves Valve locator/section contents EPV16A EPV16B Note: Proportional valve solenoid coils and electronic valve drivers are covered in section C of this

    • External cartridge valve connecting LS pressure or main pressure to tank PVG 120 – pump disconnect / block for variable pumps: • PVPE, full flow dump for the PVG 120 • External cartridge valve connecting LS pressure to tank Service Manual PVG 120 Proportional Valve Group Safety in application 520L0247 • … HYDAC proportional valves are electronically actuated valves for which the output value - pressure or flow - is changed at the same ratio as the inlet value. Control electronics and proportionally designed solenoids are required for actuation.

    proportional valve pdf

    Proportional Valve without Feedback 4WRA - Direct Operated Estimate Pressure Drop Required Across Valve (System Pressure - Load Pressure - Other Pressure Drops) Find Target Flow AtFind Target Flow At ~90% Command, Compare90% Command, Compare pcurve withabovewith above Avoid High Valve p (Above 50% System Pressure Dropped in Valve Can Cause Rotational Forces on Proportional Spool miniature proportional valve provides precise flow control of gas in proportion to input current. The valve can be controlled with either DC current . or pulse width modulation along with closed loop feedback to deliver optimal system performance. Together with its ability to provide precise control over .