Digital Gas Flow Controller - Model 651

651 Porter Digital Series 600 MFCs handle flow rates and operating pressures identical to those of the 200 Series MFCs. The Digital Series 600 MFCs feature better accuracy & repeatability than analog MFCs, performance-enhancing digital electronics, multi-gas capability & self-diagnostics.

Request additional info or a quote.
Get Info or a Quote

Series 500 & 600 Gas Mass Flow Instruments

Porter Instrument Company, Inc. is a leading manufacturer of specialized components for analytical, industrial and medical instrumentation. Since its inception in 1968, the company’s focus has been the development, manufacture and sales of precision instruments for the measurement and control of gases and liquids.
The Flowmeters, Flow Tubes, Metering Valves and Flow Controllers in this catalog are part of a unique line of control components recognized as the industry standard for critical applications in the analytical, medical, semiconductor, chemical/petrochemical, water treatment, air quality monitoring and fuel cell industries.
The people at Porter are proud of the quality reputation that our products have earned. We are ready to help you achieve new levels of performance, efficiency and reliability in your application, either with standard product or a special configuration designed to your specific requirements.

Porter Flowmeters
Porter Variable Area Flowmeters include 65mm and 150mm scale length tube assemblies and are available in either forged body or side-plate construction. Forged body models feature a wrap-around window for full 180° tube visibility, and an attractive forged one-piece black anodized aluminum body. Side-plate constructed models are conveniently interchangeable with competitive designs. Porter Control Valves, including the exclusive Torque Guard Cartridge, can be added to either style flowmeter for precise flow indication and control in one economical unit. Multi-tube side-plate models, ranging from two to six tubes, are available with or without controls valves and can include individual inlet and outlet connections or manifold ports according to your specifications.

Porter Metering Valves
Porter Metering Valves are designed for extremely precise control in low flow gas and liquid applications.

Our Model HR High Resolution Control Valve features a non-rotating valve stem with a precision ground flat for exact control and an o-ring seal for positive shut-off.  The Model HR’s springloaded, non-rising adjustment stem eliminates sawtoothing and backlash. The Model SCV Standard Cartridge Valve offers a unique blend of economy and utility for a wide range of applications. Standard Cartridge Valves are available with the exclusive Torque Guard Positive Stop Mechanism.

Porter Variable Constant Differential Flow Controller
Porter Model VCD 1000 Flow Controller is precision engineered to control low gas flows at constant mass flow rates regardless of changes in downstream pressure. The unique design yields extremely linear flow output in relation to stem rotation and virtually eliminates the sawtoothing associated with valve-based controllers. Available in full scale flow rates from 5 sccm up to 1500 sccm (He @ 70°F and 50 PSIG).

Custom Capability
Porter Flowmeters, Metering Valves and Flow Controllers can be modified to meet the particular needs of Original Equipment Manufacturers. We can also supply OEM glass flow tubes to meet specific size, scale and flow requirements. We welcome your inquiries.

Design Features & Advantages
• Interchangeable flow tube assemblies and valves allow configuration changes without removal from process system.
• Rib-guided, compression sealed flow tubes for maximum float stability.
• Ceramic scales fired on flow tubes against a contrasting background provide high visibility and durability.
• Standard or high-resolution metering valves available on inlet or outlet.
• Ten-to-one rangeability.


Note: The flow ranges listed are the minimum and maximum nitrogen (N2) flow ranges available for each given model. Intermediate flow ranges are available. For correct sizing when operating parameters are questionable, please consult the factory.

Mass Flowmeters:
Mass Flow Controllers:
Model 511: 0-5 SCCM to 0-10 SLPM N2
Model 512: 0-10 SLPM to 0-100 SLPM N2
Model 513: 0-100 SLPM to 0-500 SLPM N2
Model 514: 0-500 SLPM to 0-1000 SLPM N2
Model 521: 0-5 SCCM to 0-10 SLPM N2
Model 522: 0-10 SLPM to 0-100 SLPM N2
Model 523: 0-100 SLPM to 0-500 SLPM N2
Model 601: 0-5 SCCM to 0-10 SLPM N2
Model 651: 0-10 SLPM to 0-50 SLPM N2
Model 602: 0-10 SLPM to 0-100 SLPM N2
Model 602A: 0-10 SLPM to 0-100 SLPM N2
Model 603A: 0-100 SLPM to 0-500 SLPM N2
Model 604A: 0-500 SLPM to 0-1000 SLPM N2
Model 621: 0-5 SCCM to 0-10 SLPM N2
Model 622: 0-10 SLPM to 0-100 SLPM N2


Length: Models F65 and 65 - 65mm; Models F150 and 150 - 150mm.
Type: Fused on metering tube with contrasting yellow background.
Graduations: Standard - Models F65 and 65: 0-65mm w/ calibration data; Models F150 and 150: 0-150mm w/ calibration data. Optional: Direct reading scales.
Refer to capacity chart on page 7 of PDF
Pressure/Temperature: Neoprene packing/ Buna N O-rings - 200 psig at temperatures up to 160°F; Viton® packing/Viton O-rings - 200 psig at temperatures up to 200°F.


Accuracy: Models F65 and 65:± 10% full scale; Models F150 and 150:± 5% full scale. Accuracy specified for 100% - 10% of scale reading (10 to 1 rangeability).
Repeatability: Models F65 and 65:± 0.5% of full scale reading; Models F150 and 150: ± 0.25% of full scale reading.
Standard: 1/8" female NPT threaded adaptors with locknuts for front panel mounting. Optional: 1/8"compression fitting; 1/4" compression fitting; 1/4" NPT female; 1/4" I.D.Hose.

Metering Tube
Borosilicate glass
Standard:glass, stainless steel. Optional: sapphire, carboloy,tantalum.
Structural Members
Metering body: (F65 and F150)Black anodized aluminum.
Side Plates: (65 and 150)Standard: black anodized aluminum. Optional: stainless steel.
Wetted Parts: aluminum, brass or 316 stainless steel.

Clear polycarbonate
Tube packing and O-rings
Standard: Neoprene packing and Buna N O-rings with aluminum or brass construction. Viton packing and Viton O-rings with stainless steel construction. Optional Materials: Teflon®, EPDM, Kalrez®.

Sandvik® - AB Sandvik Materials Technology
Kalrez®, Viton® - DuPont Dow Elastomers L.L.C.
Specifications subject to change

• Integral standard cartridge or high resolution flow control valve
• Brass or 316 stainless steel wetted parts
• Special packing and o-rings
• Special process connections
• Direct reading scales
• Stainless steel side plates (Models 65 & 150 only)
• Base plate (Models 65 & 150 only)

Porter Models 65 and 150 Side-Plate Flowmeters are available in multi-tube configurations up to 6 tubes. All valve options are available, and the inlet/outlet ports can be manifolded. Contact factory for details.

Download the complete PDF for more details and ordering information

Request info or a quote on this product

Request Information

Get prompt assistance on a Parker flow product or application challenge.

Get A Quote

Need pricing on a specific or custom Parker Instrument?

Locate A Representative

Use our Rep Locator to find the appropriate representative for your area.
We'd love to share this file with you, but first you need to log in or register for an account.

First Name:
Last Name:
Porter Instrument Division respects your privacy, and does not share information with third party companies. View website policies and contact information.