PSI describes the pressure of compressed air in a pneumatic system; CFM and m³/min describe volumetric airflow over time. Pneumatic equipment requires both adequate pressure and sustained flow — evaluating either specification alone may not confirm jobsite compatibility.
Compressor selection must be based on current BORVEX technical documentation, the complete hose and connection configuration, and project-specific review. Advertised compressor ratings alone do not confirm compatibility with a pneumatic piercing tool.
Quick explanation
Contractors evaluating pneumatic equipment encounter two specifications repeatedly: pressure (PSI, bar, or MPa) and airflow (CFM or m³/min). Both appear on compressor brochures and tool data sheets, but they describe different characteristics of the air supply.
Pressure indicates how forcefully air is compressed in the system. Airflow indicates how much air volume moves through the system over time. Pneumatic piercing tools and other air-powered equipment need both — sufficient pressure within the operating range and sustained flow to maintain operation under load.
This article explains what each unit measures, why both must be evaluated together, and how hose and connection configuration affects what the tool actually receives. It is educational reference material — not compressor operating or adjustment guidance.
What PSI measures
PSI — pounds per square inch — is a unit of pressure. In pneumatic systems, it describes the force exerted by compressed air against the walls of tanks, hoses, and tool inlets.
Tool manufacturers publish operating pressure ranges that define the conditions under which equipment is designed to function. Operating outside published pressure guidance may increase wear and is not recommended.
A pressure reading at the compressor gauge confirms what is present at that point in the system. It does not, by itself, confirm that sufficient air volume is being delivered to sustain tool operation throughout a continuous run.
What CFM measures
CFM — cubic feet per minute — is a unit of volumetric flow rate. It describes how much air volume passes through a point in the system each minute under defined conditions.
Pneumatic tools consume air continuously during operation. A tool's published air consumption value indicates how much flow it requires to maintain its operating cycle. Compressor output must meet or exceed that sustained demand at working pressure.
CFM ratings on compressors and tools may reference different test conditions. Direct comparison requires understanding what each rating measures and under what reference conditions it was determined.
What m³/min measures
m³/min — cubic meters per minute — is another unit for volumetric airflow, commonly used in international specifications and some manufacturer documentation. Like CFM, it describes air volume delivered over time rather than the force of compression.
Contractors working with equipment from different regions may encounter m³/min on imported compressors or tool specifications. The conceptual role is the same as CFM: it quantifies how much air moves through the system per minute.
When comparing tool requirements against compressor output, ensure both values use the same unit or are converted using verified reference methods — not approximate field estimates.
Why pressure and airflow must be evaluated together
Pressure and airflow interact in any pneumatic system. A tool may receive adequate pressure at the inlet while the compressor cannot supply enough volume to maintain that pressure during continuous cycling.
Conversely, a compressor with high flow capacity may not deliver usable performance if pressure falls below the tool's operating range under load. Both conditions must be satisfied simultaneously for reliable field operation.
Selecting equipment based on pressure alone — or airflow alone — is a common source of compatibility errors on pneumatic piercing and other compressed-air jobsites.
Free air delivery versus advertised displacement
Compressor specifications may list displacement, free air delivery (FAD), or other output ratings. These terms describe different measurement approaches and are not interchangeable.
Displacement ratings describe theoretical pump output without accounting for real-world losses. Free air delivery typically describes actual output at defined pressure and temperature conditions — but reference conditions vary by manufacturer.
When matching a compressor to a pneumatic piercing tool, compare sustained output at working pressure against the tool's published air consumption. Do not assume advertised displacement equals delivered air at the tool inlet.
Delivery losses
Air loses effective delivery capacity as it travels from the compressor through hose, couplings, fittings, and adapters to the tool. These losses affect both pressure and flow at the tool inlet.
Losses increase with hose length, smaller inside diameter, additional connection points, bends, and leaks. The compressor gauge may show acceptable pressure while the tool receives significantly less under continuous demand.
Evaluating compatibility at the compressor alone — without accounting for the delivery path — does not confirm what the tool will receive during operation.
Hose and coupling restrictions
Hose inside diameter and coupling bore diameter constrain how much air can pass through the supply path. Restrictive components create bottlenecks that reduce effective delivery even when the compressor is adequately sized.
Quick-connect fittings, hose reels, reducer adapters, and worn couplings are common restriction points. Each additional connection in the path adds potential for measurable loss under flow.
Use rated hose and connection assemblies matched to tool requirements. Inspect couplings for wear and secure engagement before each use. Improvised adapter chains increase restriction risk.
Continuous demand
Pneumatic piercing tools operate with continuous air demand during a bore. Unlike intermittent shop tools that cycle on and off, displacement boring may require sustained flow for extended periods.
Compressors rated for peak or intermittent output may not maintain required pressure and flow under continuous load. Duty cycle, tank size, and pump capacity all influence whether sustained delivery is achievable.
Plan for continuous demand when comparing compressor specifications against tool air consumption — not just momentary or startup conditions.
Reading compressor specifications
Compressor data plates and brochures typically list multiple ratings — pressure, displacement, free air delivery, tank volume, and duty cycle. Each describes a different aspect of performance.
Identify which rating reflects sustained output at the pressure level relevant to your tool. Note the reference conditions under which the rating was measured — temperature, altitude, and test standard may differ from field conditions.
If compressor specifications are unclear or incomplete, contact the compressor manufacturer or BORVEX for guidance before relying on the unit for pneumatic piercing work.
Reading tool specifications
Tool technical data sheets publish operating air pressure and air consumption for each model. BORVEX BX Series specifications are available through the Downloads Center, Compare page, and centralized technical data.
Operating pressure is typically expressed as a range. Air consumption may appear as a single value or range depending on the model and reference conditions. Recommended compressor guidance provides additional context for matching.
Use current verified documentation — not general product descriptions or third-party summaries — when comparing tool requirements against available compressor capacity.
Common misunderstandings
Several misconceptions appear frequently in equipment discussions. Clarifying them helps contractors avoid compatibility errors.
Higher pressure does not automatically mean better tool performance. Operating above manufacturer pressure guidance increases wear and is not recommended. Adequate sustained flow at the correct working pressure matters more than maximum available pressure.
- PSI and CFM are not interchangeable — they measure different properties of the air supply
- Compressor tank pressure at rest does not confirm sustained delivery under tool load
- Advertised compressor CFM may not equal delivered air at the tool inlet
- A compressor with high PSI but low CFM may not suit continuous-demand pneumatic tools
- m³/min and CFM both describe airflow — they are not pressure units
- Oversizing compressor pressure rating alone does not resolve restrictive hose or coupling losses
Practical evaluation checklist
Use this checklist when evaluating whether a compressor and air path may suit a pneumatic piercing tool. It supports planning — not field adjustment or modification.
- Identify the specific tool model and review its published operating pressure and air consumption
- Confirm compressor sustained output at working pressure meets or exceeds tool requirements
- Document hose inside diameter, total length, and all coupling types in the delivery path
- Assess duty cycle against expected continuous run duration for the bore
- Account for simultaneous air demand from other equipment on the jobsite
- Compare complete setup against current BORVEX technical documentation
- Contact BORVEX for application confirmation before mobilization
BX Series context
Each BORVEX BX Series model publishes operating air pressure, air consumption, and recommended compressor guidance in its technical data sheet. These values define the air-supply requirements contractors should compare against available compressor capacity.
Air requirements vary across the series. Review verified specifications for the specific model under consideration — not an approximate value from a different model in the lineup.
The Compare page and Downloads Center provide side-by-side access to current BX Series air specifications. Contact BORVEX with complete compressor and hose details to confirm compatibility.
Pneumatic terminology reference
Common units encountered in compressor and tool specifications. This table explains what each unit measures — not conversion relationships.
| Unit | What it measures | Typical use in specs |
|---|---|---|
| PSI | Pressure — force of compressed air per unit area | Operating pressure ranges on tools; tank and output pressure on compressors |
| bar | Pressure — metric unit of compressed air force per unit area | Operating pressure on international tool and compressor specifications |
| MPa | Pressure — megapascal, a metric pressure unit used in engineering contexts | Technical documentation and engineering specifications for pneumatic systems |
| CFM | Volumetric airflow — cubic feet of air delivered per minute | Air consumption on tools; output ratings on compressors |
| m³/min | Volumetric airflow — cubic meters of air delivered per minute | Air consumption and compressor output on international specifications |
BORVEX BX Series overview
BORVEX manufactures BX Series pneumatic piercing tools for underground conduit and utility pathway work. Brief model summaries below use centralized BORVEX technical data. Contact BORVEX to confirm application fit before specifying any model.
Final tool selection depends on conduit outside diameter, bore distance, soil conditions, required depth, compressor output, hose configuration, launch and receiving space, existing utilities and jobsite requirements. Contact BORVEX before selecting or operating a model.
BX60
- Outside diameter
- 60 mm
- Recommended bore
- 40–140 mm
- Air consumption
- 0.6–1.2 m³/min
BX75
- Outside diameter
- 75 mm
- Recommended bore
- 40–140 mm
- Air consumption
- 0.6–1.5 m³/min
BX90
- Outside diameter
- 90 mm
- Recommended bore
- 40–140 mm
- Air consumption
- 1.2–2.0 m³/min
BX105
- Outside diameter
- 105 mm
- Recommended bore
- 40–140 mm
- Air consumption
- 1.6–2.5 m³/min
BX120
- Outside diameter
- 120 mm
- Recommended bore
- 40–140 mm
- Air consumption
- 2.0–3.0 m³/min
BX140
- Outside diameter
- 140 mm
- Recommended bore
- 40–140 mm
- Air consumption
- 3.0–4.0 m³/min
Frequently asked questions
PSI measures pressure — the force of compressed air in the system. CFM measures volumetric airflow — how much air volume is delivered per minute. Pneumatic tools require both adequate pressure within the operating range and sustained CFM to maintain performance under load.