Puritan Bennett Puritan Bennett MA1
Puritan Bennett · Model Puritan Bennett MA1
The Bennett MA-1 ventilator is a volume-cycled, constant flow generator that can act as an assistor, controller, or assist-controller. It is one of the most commonly used ventilators in clinical practice. With this unit, inspiration continues until a preset tidal volume is delivered to the patient--unless impedances to gas flow increase system pressures to a preselected limit. Thus, setting the maximum inspiratory pressure too low limits the ability of the ventilator to deliver the tidal volume, causing it to function as a pressure-cycled device. Other basic controls allow you to establish the sensitivity of the ventilator to spontaneous breathing attempts, the maximum flow rate, the frequency of respirations, and the oxygen percentage. Special controls permit delivery of a sigh breath and slowing of exhalation.
Key tips
- ·Never disable a low-pressure/circuit-disconnect alarm while troubleshooting - silence it, don't disable it.
- ·Verify the O2 supply source and pressure before assuming an internal fault.
- ·Circuit type must match the patient population (adult/pediatric/neonatal) - a mismatched circuit invalidates delivered volumes.
Typical Failure Modes
Failure patterns typical of this equipment class - general BMET reference, not verified against this exact unit's own service history unless flagged. Severity is a category-level estimate.
Compressor / turbine failure
HighSymptoms: Unable to reach set pressure, low-flow alarm, loud noise.
Root cause: Worn bearings or failed blower motor.
Power supply / battery failure
HighSymptoms: Unexpected shutdown, persistent low-battery alarm.
Root cause: Aged internal battery or failed PSU.
Patient circuit leak
LowSymptoms: Leak alarm, low circuit pressure, volume loss.
Root cause: Disconnected or punctured patient circuit / humidifier.
O2 blender / mixer fault
MediumSymptoms: FiO2 out of range, oxygen alarm.
Root cause: Failed solenoid or proportional valve in blender.
Serviceable Parts & Consumables
The parts a BMET typically services on this class of equipment. Service class and relative cost are general engineering estimates for the category, not figures from this unit's documentation. Part numbers appear only when pulled from this unit's own service manual. Always confirm intervals and pricing against the manufacturer.
O2 sensor (galvanic/paramagnetic)
Class Frequent wear itemRel. cost $$R&R Fairly easy
Exhalation valve assembly
Most-replaced wearable part; stock spares.
Class Frequent wear itemRel. cost $$R&R Fairly easy
Flow / differential pressure sensor
Class Periodic replacementRel. cost $$$R&R Moderate
Bacterial / HEPA filter
Consumable, replace per PM schedule.
Class ConsumableRel. cost $R&R Easy
| Part | Service class | Relative cost | R&R difficulty |
|---|---|---|---|
| O2 sensor (galvanic/paramagnetic) | Frequent wear item | $$ | Fairly easy |
| Exhalation valve assembly Most-replaced wearable part; stock spares. | Frequent wear item | $$ | Fairly easy |
| Flow / differential pressure sensor | Periodic replacement | $$$ | Moderate |
| Bacterial / HEPA filter Consumable, replace per PM schedule. | Consumable | $ | Easy |
Relative cost: $ lowest · $$$$ highest service-part cost for this equipment class. Not a price.
PM Checklist
Preventive-maintenance tasks typical of this equipment class. Perform to the manufacturer's procedure and your facility's policy - this is general reference, not a schedule for this specific unit.
- ·Daily pre-use check: self-test, circuit integrity, alarm function
- ·Scheduled circuit and inspiratory filter replacement per manufacturer interval
- ·Flow and pressure sensor calibration verification
- ·Battery load test and runtime check
- ·Annual full PM and electrical safety test
Troubleshooting Approach
A structured starting point derived from the failure modes above. Follow the manufacturer's service documentation for the actual procedure.
Symptom: Exhalation valve leak / failure
- Confirm the presentation - typically low exhaled tidal volume, high leak alarm, inability to maintain PEEP - and note the exact alarm or message and the conditions when it occurs.
- Check the most likely cause first: diaphragm/valve degraded by secretions and cleaning cycles.
- Isolate the affected subsystem using the manufacturer's functional check or self-test, where one is provided.
- If the fault is confirmed and not a field adjustment, service or replace the exhalation valve assembly per the manufacturer's service documentation.
- Return the device to service only after the manufacturer's functional and applicable electrical-safety checks pass.
- Record the findings, any parts used, and the verification results in the maintenance history.
Symptom: Flow / pressure sensor drift
- Confirm the presentation - typically inaccurate delivered volume, false volume/pressure alarms - and note the exact alarm or message and the conditions when it occurs.
- Check the most likely cause first: sensor contamination or aging of differential-pressure transducer.
- Isolate the affected subsystem using the manufacturer's functional check or self-test, where one is provided.
- If the fault is confirmed and not a field adjustment, service or replace the flow / differential pressure sensor per the manufacturer's service documentation.
- Return the device to service only after the manufacturer's functional and applicable electrical-safety checks pass.
- Record the findings, any parts used, and the verification results in the maintenance history.
Typical Location
Where this class of equipment is typically deployed - general reference, not this unit's own placement record.
- ICU / CCU
- Emergency Department
- Operating Room (anesthesia-adjacent)
- NICU
- Respiratory Therapy department
- Patient transport
Documents & Manuals
No documents available for this device yet.
Safety & Recalls
Synced live from the FDA openFDA API.
- RECALL
Shaft breaks so that adequate patient specimen sample cannot be obtained.
- RECALL
Directions for Use-Puritan Bennett has determined that a service interval should be defined for the device. The firm has also determined that an exhalation filter should be employed when the device is in use.
- RECALL
Manufacturing defect at contract manufacturer, employee error, poor training, improper inspection.
Troubleshoot this device with Bio
Describe a symptom or error code. Bio answers from this device's own documented error codes, failure modes, parts, and guides.
Ask Bio →