Description
Overview
The Type 7150 Precision Air Relay is a high-precision, multi-stage pneumatic pressure relay designed to provide fine adjustment and maximum stability under variable operating conditions. It combines the proven precision control technology of the ControlAir Type 200 with the high forward and reverse flow capability of the Type 6100 1:1 Relay Volume Booster.
A highly sensitive measuring capsule controls pilot pressure for crisp and accurate adjustment, while the relay’s high-flow design provides relief capacity up to 80 scfm. This combination of dynamic sensitivity, stable output, and high forward and reverse flow makes the Type 7150 particularly well suited for demanding pneumatic control and counterbalance applications.
The Type 7150 is available with 1/4″, 1/2″, or 3/4″ NPT supply and output ports and offers positive and negative bias capability. A balanced supply valve minimizes the effect of supply pressure variations, while an isolated control chamber helps maintain stable output during changing flow conditions.
Key Features
- High-precision multi-stage pressure relay
- Fine pressure adjustment
- High forward and reverse flow capacity
- 1/4″, 1/2″, or 3/4″ NPT supply and output porting
- Relief capacity up to 80 scfm
- Sensitivity to output pressure deviations of less than 1/4 inch water column
- Highly sensitive capsule for precise pilot pressure control
- Isolated control chamber helps maintain stable output
- Balanced supply valve minimizes supply pressure effects
- Positive and negative bias capability
- Bias adjustment range from -30 psig to +100 psig
- Two 1/4″ NPT gauge ports
- Optional tapped exhaust for captured exhaust applications
- Pipe, panel, or bracket mounting
Performance Characteristics
- Output Pressure Range: 2-120 psig (0.14-8.2 bar)
- Maximum Supply Pressure: 250 psig (17 bar)
- Maximum Signal Pressure: 120 psig (8 bar)
- Maximum Output Pressure: 120 psig (8 bar)
- Bias Range: -30 psig (-2 bar) to +100 psig (6.7 bar)
- Air Consumption: 14 scfh (6.6 Nl/min)
- Bleed Rate: Less than 0.08 scfm (2.3 Nl/min)
- Sensitivity: Less than 1/4″ (6.3 mm) water column
- Supply Pressure Effect: 0.05 psig for a 100 psig supply pressure change
- Temperature Range: -20°F to 160°F (-29°C to 71°C)
- 3/4″ Forward Flow Coefficient (Cv): 5.0
- 3/4″ Exhaust Flow Coefficient (Cv): 3.5
- 1/2″ Forward Flow Coefficient (Cv): 4.5
- 1/2″ Exhaust Flow Coefficient (Cv): 3.5
- 1/4″ Forward Flow Coefficient (Cv): 2.0
- 1/4″ Exhaust Flow Coefficient (Cv): 2.5
- 3/4″ Exhaust Capacity: 80 scfm (2,264 Nl/min)
- 1/2″ Exhaust Capacity: 75 scfm (2,123 Nl/min)
- 1/4″ Exhaust Capacity: 35 scfm (991 Nl/min)
- Supply/Output Ports: 1/4″, 1/2″, or 3/4″ NPT
- Signal Port: 1/4″ NPT
- Gauge Ports: Two 1/4″ NPT
- Exhaust Ports: Two 7/16″ openings or optional 1/4″ NPT tapped exhaust
- Mounting: Pipe, panel, or bracket
- Weight: 2.5 lbs (1.13 kg)
The Type 7150 combines high sensitivity with substantial forward and exhaust flow capability. The specification sheet shows maximum flow of approximately 110 scfm for the 1/4″ version, 235 scfm for the 1/2″ version, and 265 scfm for the 3/4″ version under the stated flow-curve conditions.
Its supply pressure effect is only 0.05 psig for a 100 psig supply pressure change, helping provide stable output in pneumatic systems with varying supply conditions.
How to Select the Right Configuration
Selecting the correct Type 7150 configuration depends primarily on the required airflow, connection size, bias requirements, and exhaust configuration.
- Select the 1/4″ NPT model for lower-flow applications requiring a maximum forward Cv of 2.0
- Select the 1/2″ NPT model for higher-flow applications requiring a maximum forward Cv of 4.5
- Select the 3/4″ NPT model for the highest available flow capacity with a maximum forward Cv of 5.0
- Use the adjustable bias capability when output pressure must be offset positively or negatively relative to the input signal
- Select the Tapped Exhaust option when downstream exhaust air must be captured or routed away from the relay
- Choose pipe, panel, or bracket mounting based on installation requirements
- Select the appropriate port size based on actuator volume and required forward and exhaust flow
For additional guidance:
Applications
The Type 7150 Precision Air Relay is suited for pneumatic applications requiring precise pressure control combined with high forward and reverse airflow. Its high relief capacity and dynamic sensitivity make it particularly suitable for pneumatic counterbalance systems.
- Pneumatic counterbalance systems
- Control valve actuators
- Large-volume pneumatic actuators
- Diaphragm actuators
- Piston actuators
- Precision pneumatic pressure control
- Remote pressure control
- Volume boosting
- Process control systems
- Industrial automation equipment
- Applications requiring positive or negative pressure bias
- Systems requiring high forward and reverse flow
Principle of Operation
The Type 7150 uses a multi-stage pneumatic control system in which the input signal acts on a sensitive measuring capsule to control pilot pressure. The pilot stage then controls the high-flow booster section, allowing the relay to combine precision pressure regulation with substantially greater forward and exhaust flow.
As the signal changes, pilot pressure controls the main diaphragm and valve assembly to increase or decrease output pressure. The balanced supply valve minimizes the influence of changes in supply pressure, while the isolated control chamber reduces output variation and vibration during flowing conditions.
The principle-of-operation diagram on page 2 of the specification sheet identifies the signal pressure, supply pressure, output pressure, atmospheric pressure, and pilot pressure paths through the multi-stage relay.
Models & Configurations
Type 7150 Ordering Structure
7150-[Port Size][Range][Options]
Port Size
- B = 1/4″ NPT
- D = 1/2″ NPT
- E = 3/4″ NPT
Pressure Range
- C = 2-120 psig (0.14-8.2 bar)
Available Options
- E = Tapped Exhaust; allows captured exhaust from the two 1/4″ NPT spacer ports and barbed bleed screw
The Type 7150 ordering system combines the selected 1/4″, 1/2″, or 3/4″ NPT port size with the 2-120 psig output range and optional tapped exhaust configuration.
Accessories
- Zinc Plated Steel Mounting Bracket: P/N 449-542-045
- 1/4″ NPT Plated Steel Exhaust Screen/Muffler Fitting: P/N 445-761-008
The exhaust screen/muffler fitting requires the Type 7150 to be ordered with the E tapped exhaust option.
Materials of Construction
- Housing: Die-Cast Aluminum Alloy and Zinc Alloy
- Bolting: Zinc Plated Steel
- Internal Components: Stainless Steel, Plated Steel, Brass, and Aluminum
- Elastomers: Nitrile
The Type 7150 combines die-cast aluminum and zinc alloy housing components with stainless steel, plated steel, brass, and aluminum internal components for industrial pneumatic service.
Technical Resources
FAQs
What is the Type 7150 precision air relay used for?
The Type 7150 is used for precision pneumatic pressure control where high forward and reverse flow capacity is also required. Its high relief capacity and dynamic sensitivity make it particularly suited for pneumatic counterbalance applications.
What is the output pressure range of the Type 7150?
The Type 7150 provides an output pressure range of 2-120 psig (0.14-8.2 bar).
What is the maximum supply pressure?
The maximum supply pressure for the Type 7150 is 250 psig (17 bar).
How sensitive is the Type 7150?
The Type 7150 senses output pressure deviations of less than 1/4 inch (6.3 mm) water column.
What is the bias range of the Type 7150?
The Type 7150 provides positive and negative bias adjustment from -30 psig (-2 bar) to +100 psig (6.7 bar).
What port sizes are available for the Type 7150?
The Type 7150 is available with 1/4″, 1/2″, or 3/4″ NPT supply and output ports. The signal port and two gauge ports are 1/4″ NPT.
What is the exhaust capacity of the Type 7150?
Exhaust capacity depends on port size. The 1/4″ model provides up to 35 scfm, the 1/2″ model provides up to 75 scfm, and the 3/4″ model provides up to 80 scfm.
How does the Type 7150 maintain stable output pressure?
An isolated control chamber helps prevent output variation and vibration during changing flow conditions, while the balanced supply valve minimizes output changes caused by supply pressure variation.
What is the supply pressure effect of the Type 7150?
The Type 7150 has an output variation of approximately 0.05 psig for a 100 psig change in supply pressure.
Can the Type 7150 provide captured exhaust?
Yes. The optional tapped exhaust configuration allows exhaust to be captured through two 1/4″ NPT spacer ports and a barbed bleed screw.
How can the Type 7150 be mounted?
The Type 7150 can be pipe mounted, panel mounted, or installed using an optional mounting bracket.
What is the operating temperature range?
The Type 7150 operates from -20°F to 160°F (-29°C to 71°C).
