Description
Overview
The Type 650 Positive Bias Relay is a signal-operated regulator designed to increase pneumatic flow capacity while adding an adjustable preset bias pressure to the input signal. The resulting output pressure is the sum of the input signal pressure plus the selected bias setting, making the Type 650 well suited for increased flow capacity and remote pressure control applications.
Designed to convert a low-flow control signal to the higher flow requirements of an operating system, the Type 650 provides flow capacity up to 50 SCFM with minimal pressure drop. Four primary bias ranges allow the relay to accommodate applications requiring different levels of added pressure.
A balanced supply valve with a rolling diaphragm helps minimize the effect of supply pressure changes, while high sensitivity provides accurate conversion of the input signal to output pressure without lag. A large relief valve provides up to 15 SCFM exhaust capacity for responsive downstream pressure control.
Key Features
- Signal-operated positive bias relay
- Adds adjustable preset bias pressure to the input signal
- High flow capacity up to 50 SCFM
- Four primary adjustable bias ranges from 0-15 psig through 0-150 psig
- 0-2 psig bias range available with selected port sizes
- High relief capacity up to 15 SCFM
- Balanced supply valve design
- Rolling diaphragm helps minimize the effect of supply pressure variation
- High sensitivity for accurate pressure conversion
- Accurate signal-to-output conversion without lag
- 1/4″, 3/8″, and 1/2″ NPT port sizes available
- Optional BSP porting
- Pipe, panel, or bracket mounting
- Tapped exhaust option available
- Tamperproof cover option available
- ATEX 2014/34/EU option available
- Fixed negative bias option available
Performance Characteristics
- Flow Capacity: 50 SCFM (1,415 Nl/min) at 100 psig (7 bar) supply with 20 psig (1.4 bar) output
- Exhaust Capacity: 15 SCFM (425 Nl/min) with downstream pressure 5 psig (0.35 bar) above set pressure
- Sensitivity: 1/4″ (3.2 mm) water column
- Supply Pressure Effect: 0.1 psi output change for a 50 psig supply pressure change
- Maximum Supply Pressure: 250 psig (17 bar)
- Maximum Signal Pressure: 150 psig (10 bar)
- Maximum Output Pressure: 150 psig (10 bar)
- Bias Ranges: 0-2 psig, 0-15 psig, 0-30 psig, 0-60 psig, and 0-150 psig depending on port size
- Ambient Temperature Range: -40°F to 160°F (-40°C to 71°C)
- Weight: 1.75 lbs (635 g)
- Mounting: Pipe, panel, or bracket
- Port Sizes: 1/4″, 3/8″, and 1/2″ NPT
These performance characteristics allow the Type 650 to boost the flow capacity of low-flow pneumatic control signals while maintaining accurate and responsive pressure control.
How to Select the Right Configuration
Selecting the correct Type 650 configuration depends on the required bias pressure range, port size, connection type, mounting requirements, and installation environment.
- Select the 0-2 psig bias range for applications requiring a small positive pressure offset
- Select the 0-15 psig range for low-pressure positive bias applications
- Select the 0-30 psig range for general pneumatic pressure control
- Select the 0-60 psig range when a larger adjustable pressure offset is required
- Select the 0-150 psig range for applications requiring the widest available positive bias adjustment
- Choose 1/4″, 3/8″, or 1/2″ porting based on piping and system requirements
- Select the Tapped Exhaust option when captured exhaust is required
- Choose the Tamperproof Cover option to help prevent casual adjustment of the bias setting
- Select BSP Porting when BSP connections are required
- Select the ATEX option when ATEX 2014/34/EU compliance is required
- Select the Negative Bias option when a built-in -4 ±1 psig bias is required
For additional guidance:
Applications
The Type 650 Positive Bias Relay is commonly used where a low-flow pneumatic control signal must operate equipment requiring greater flow capacity or where an adjustable pressure bias must be added to the input signal.
- Remote pressure control
- Volume boosting
- Low-flow signal amplification
- Pneumatic control systems
- Process control equipment
- Control valve and actuator systems
- Industrial automation equipment
- OEM pneumatic systems
- Applications requiring an adjustable positive pressure bias
- Applications requiring increased flow from a low-flow control signal
Principle of Operation
Signal pressure introduced through the signal port combines with the force of the adjustable bias spring to create a downward force on the upper diaphragm area. This force is balanced by output pressure acting against the lower control diaphragm.
When signal pressure or bias spring force increases above the output pressure, the resulting downward force moves the diaphragm assembly and opens the supply valve. Output pressure then increases until equilibrium is restored. This operating principle allows the Type 650 to produce an output equal to the input signal pressure plus the selected bias pressure.
Models & Configurations
Type 650 Ordering Structure
650-[Port Size][Bias Range][Options]
1/4″ NPT Models
- 650-BA = 1/4″ NPT, 0-2 psig (0-0.14 bar) bias range
- 650-BC = 1/4″ NPT, 0-15 psig (0-1 bar) bias range
- 650-BD = 1/4″ NPT, 0-30 psig (0-2 bar) bias range
- 650-BE = 1/4″ NPT, 0-60 psig (0-4 bar) bias range
- 650-BF = 1/4″ NPT, 0-150 psig (0-10 bar) bias range
3/8″ NPT Models
- 650-CC = 3/8″ NPT, 0-15 psig (0-1 bar) bias range
- 650-CD = 3/8″ NPT, 0-30 psig (0-2 bar) bias range
- 650-CE = 3/8″ NPT, 0-60 psig (0-4 bar) bias range
- 650-CF = 3/8″ NPT, 0-150 psig (0-10 bar) bias range
1/2″ NPT Models
- 650-DA = 1/2″ NPT, 0-2 psig (0-0.14 bar) bias range
- 650-DC = 1/2″ NPT, 0-15 psig (0-1 bar) bias range
- 650-DD = 1/2″ NPT, 0-30 psig (0-2 bar) bias range
- 650-DE = 1/2″ NPT, 0-60 psig (0-4 bar) bias range
- 650-DF = 1/2″ NPT, 0-150 psig (0-10 bar) bias range
Available Options
- E = Tapped Exhaust; 1/8″ NPT port allows captured exhaust
- T = Tamperproof Cover; prevents casual adjustment of bias setting
- U = BSP Porting
- X = ATEX 2014/34/EU
- Z = Negative Bias; built-in -4 ±1 psig bias
The complete model, bias range, port size, option, and accessory information is provided in the ordering section on page 2 of the Type 650 specification sheet.
Accessories
- Mounting Bracket: P/N 446-707-025
- 0-15 psi Gauge: P/N 446-725-003
- 0-30 psi Gauge: P/N 446-725-004
- 0-60 psi Gauge: P/N 446-725-001
- 0-160 psi Gauge: P/N 446-725-002
Materials of Construction
- Body: Die-cast aluminum
- Internal Components: Stainless steel, brass, plated steel, and acetal
- Diaphragm: Nitrile elastomer with polyester fabric
- Knob: ABS plastic
Technical Resources
FAQs
What is the Type 650 positive bias relay used for?
The Type 650 is used to increase the flow capacity of a pneumatic control signal while adding an adjustable preset bias pressure. It is commonly used for increased flow capacity and remote pressure control applications.
How does the Type 650 positive bias relay work?
The Type 650 combines the input signal pressure with force from an adjustable bias spring. The regulator increases output pressure until the diaphragm assembly reaches equilibrium, producing an output equal to the input signal pressure plus the selected bias pressure.
What is the maximum flow capacity of the Type 650?
The Type 650 provides flow capacity up to 50 SCFM (1,415 Nl/min) at 100 psig supply with 20 psig output.
What bias pressure ranges are available?
Available bias ranges include 0-2 psig, 0-15 psig, 0-30 psig, 0-60 psig, and 0-150 psig. Available ranges vary depending on the selected port size.
What is the maximum supply pressure?
The maximum supply pressure for the Type 650 is 250 psig (17 bar).
What is the maximum output pressure?
The maximum output pressure is 150 psig (10 bar).
What is the relief capacity of the Type 650?
The Type 650 provides up to 15 SCFM (425 Nl/min) exhaust capacity when downstream pressure is 5 psig above the set pressure.
What port sizes are available?
The Type 650 is available with 1/4″, 3/8″, and 1/2″ NPT port sizes. BSP porting is also available as an option.
Can the Type 650 be panel mounted?
Yes. The Type 650 can be pipe, panel, or bracket mounted.
Is a negative bias configuration available?
Yes. The Z option provides a built-in -4 ±1 psig negative bias.
Is an ATEX option available?
Yes. An ATEX 2014/34/EU option is available for the Type 650.
