Description
Overview
The Type 855BP Miniature Back Pressure Regulator is a compact, economical pneumatic relief regulator with an adjustable setpoint. Its primary function is to protect downstream pneumatic systems from excessive pressure buildup by relieving air when system pressure rises above the selected setting.
A highly sensitive diaphragm-operated design provides accurate and repeatable pressure relief, while the push-pull locking knob makes setpoint adjustment easy and helps prevent unintended changes. With a lightweight body and 1/4″ NPT process connections, the Type 855BP is well suited for compact OEM equipment and space-constrained pneumatic installations.
Five output pressure ranges are available from 0-5 psig through 0-100 psig. The Type 855BP can provide relief flow up to 35 scfm, depending on the selected setpoint and system pressure.
Key Features
- Compact miniature back pressure regulator
- Economical pneumatic overpressure protection
- Adjustable pressure setpoint
- Highly sensitive diaphragm-operated design
- Accurate and repeatable pressure relief
- Relief flow capacity up to 35 scfm (990 Nl/min)
- Push-pull locking adjustment knob
- Easy and accurate pressure adjustment
- Five available pressure ranges
- 1/4″ NPT inlet and outlet ports
- Two 1/8″ NPT gauge ports
- Maximum system pressure of 250 psig (17.2 bar)
- Compact and lightweight at 4.0 oz. (113 g)
- Optional mounting bracket and panel nut
- Low-cost choice for OEM pneumatic systems
Performance Characteristics
- Relief Capacity: Up to 35 scfm (990 Nl/min), depending on setpoint pressure and system conditions
- Maximum System Pressure: 250 psig (17.2 bar)
- Operating Temperature: 0°F to 150°F (-18°C to 60°C)
- Inlet and Outlet Porting: 1/4″ NPT
- Gauge Ports: Two 1/8″ NPT ports
- Output Pressure Ranges: 0-5 psig, 0-15 psig, 0-30 psig, 0-60 psig, and 0-100 psig
- Spring and Adjustment Screw Material: Zinc-plated steel
- Body Material: Epoxy-coated zinc
- Bonnet and Piston Material: Acetal
- Diaphragm and O-Ring Material: Nitrile
- Valve Seat Material: Aluminum
- Weight: 4.0 oz. (113 g)
Relief capacity depends on the selected setpoint and the amount of pressure rise above that setpoint. For example, a Type 855BP set to begin relieving at 20 psig can flow approximately 9 scfm if system pressure rises to 30 psig.
How to Select the Right Configuration
Selecting the proper Type 855BP configuration depends on the required setpoint range, anticipated relief flow, system pressure, gauge requirements, and mounting method.
- Choose the 0-5 psig range for very low-pressure pneumatic protection.
- Choose the 0-15 psig range for low-pressure instrumentation and compact control systems.
- Choose the 0-30 psig range for general low-pressure pneumatic equipment.
- Choose the 0-60 psig range for common industrial air applications.
- Choose the 0-100 psig range for higher-pressure pneumatic systems.
- Confirm that the required relief flow is within the regulator’s 35 scfm maximum capacity.
- Review the flow curve to verify relief capacity at the selected setpoint and allowable pressure rise.
- Use the push-pull locking knob when frequent field adjustment is expected.
- Add the mounting bracket for side mounting to a machine frame or support surface.
- Add the panel nut when the regulator will be mounted through a control panel.
- Select a gauge range that allows the intended setpoint to be read clearly.
For additional guidance:
Applications
The Type 855BP is designed for compact pneumatic systems that require economical, repeatable overpressure protection.
- OEM pneumatic equipment
- Compact control panels
- Packaging machinery
- Assembly equipment
- Laboratory and test systems
- Pneumatic instrumentation
- Small compressor systems
- Air-operated devices
- Industrial automation equipment
- Pressure relief and bypass circuits
- Space-constrained pneumatic installations
During normal operation, the Type 855BP remains closed. When system pressure exceeds the selected setpoint, the valve opens and relieves excess pressure until the system returns below the setpoint.
Models & Configurations
Type 855BP Ordering Structure
855 – B [Output Range]
Port Size
- B = 1/4″ NPT
Output Pressure Ranges
- E = 0-5 psig (0-0.4 bar)
- A = 0-15 psig (0-1.0 bar)
- B = 0-30 psig (0-2.1 bar)
- C = 0-60 psig (0-4.1 bar)
- D = 0-100 psig (0-6.9 bar)
Accessories
- Mounting Bracket: P/N 446-707-100
- Panel Nut: P/N 442-734-040
- 0-15 psi Gauge: P/N 446-725-005
- 0-30 psi Gauge: P/N 446-725-006
- 0-60 psi Gauge: P/N 446-725-007
- 0-160 psi Gauge: P/N 446-725-008
Technical Resources
- Product Data Sheet
- Installation Instructions
- Product Configurator
- 3D CAD Models
- Engineering Support Resources
FAQs
What is the Type 855BP miniature back pressure regulator used for?
The Type 855BP protects compact pneumatic systems from excessive pressure buildup by relieving air when system pressure rises above its adjustable setpoint.
What is the maximum relief flow capacity?
The Type 855BP can provide relief flow up to 35 scfm (990 Nl/min), depending on the selected setpoint and system pressure.
What pressure ranges are available?
The Type 855BP is available in 0-5 psig, 0-15 psig, 0-30 psig, 0-60 psig, and 0-100 psig pressure ranges.
What is the maximum system pressure?
The maximum system pressure for the Type 855BP is 250 psig (17.2 bar).
What port sizes are available?
The Type 855BP has 1/4″ NPT inlet and outlet ports and two 1/8″ NPT gauge ports.
How does the push-pull locking knob work?
The knob can be pulled to allow pressure adjustment and pushed to help lock the selected setpoint in place.
Can the Type 855BP be panel mounted?
Yes. An optional panel nut is available for panel mounting, and an optional bracket is available for side mounting.
How much does the Type 855BP weigh?
The Type 855BP weighs approximately 4.0 oz. (113 g).
