Demand for differential pressure gauges in Tan Duc Industrial Park

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Tan Duc Industrial Park accommodates a wide range of industrial manufacturing activities, including mechanical engineering, electrical and electronic products, food processing, packaging, consumer goods and supporting industries.

Factories operating cleanrooms, laboratories, dust-controlled production areas, food-processing lines, pharmaceutical areas, medical-device production or precision-manufacturing spaces need more than basic temperature and humidity control.

HVAC systems must also maintain suitable filtration performance, airflow direction and pressure relationships between controlled spaces.

A differential pressure gauge measures the pressure difference between two locations.

It may be installed between a cleanroom and a corridor, between a cleanroom and an airlock, between areas with different environmental-control requirements or upstream and downstream of a HEPA filter.

Differential pressure gauges are also widely used on AHUs, HEPA Boxes, Dynamic Pass Boxes, dispensing booths, LAF units, FFUs and other controlled-air equipment.

For cleanroom contractors, correct instrument selection during the design stage helps reduce changes during installation, testing, commissioning and project acceptance.

What is a differential pressure gauge?

A differential pressure gauge measures the difference between two pressure points.

It normally includes a high-pressure port and a low-pressure port connected to the monitored locations through pressure tubing.

The displayed reading represents the difference between the two pressures rather than the absolute pressure at either point.

In cleanrooms, differential pressure gauges are commonly used to monitor room-to-room pressure relationships.

In filtration systems, the same measurement principle is used to monitor pressure loss across an air filter.

Mechanical gauges provide simple local indication, while digital gauges and transmitters may provide alarms, signal outputs, data recording and integration with PLC or building-management systems.

Why differential pressure matters in cleanrooms

Air naturally tends to move from an area of higher pressure toward an area of lower pressure.

Cleanroom HVAC systems use this principle to create the intended direction of airflow between controlled areas.

Where product protection is required, a cleaner room is commonly maintained at higher pressure than its adjacent space. When a door opens or minor leakage occurs, air tends to flow outward, helping reduce the entry of uncontrolled air.

For containment applications involving dust, chemicals or other materials that should remain inside the process area, selected rooms may operate under negative pressure.

There is no single differential-pressure target that is suitable for every cleanroom.

The required pressure relationship depends on the manufacturing process, room tightness, door-opening frequency, supply airflow, return airflow and contamination-control strategy.

A differential pressure gauge gives operators a practical indication of whether the intended pressure relationship is being maintained.

Room-pressure monitoring

Factories in Tan Duc Industrial Park may install differential pressure gauges between production rooms and corridors, between cleanrooms and airlocks or between areas with different environmental requirements.

The gauge display is normally installed near the entrance so that operators can inspect the reading conveniently.

Pressure taps should be located where they represent room static pressure.

They should not be installed directly in a strong supply-air stream or too close to a fan, where dynamic pressure may influence the measurement.

If differential pressure falls unexpectedly, possible causes include an open door, damaged door seals, reduced supply airflow, increased return airflow, unstable fan performance or changes in damper position.

An unusually high pressure difference may also indicate restricted return airflow, increased supply volume or changes in door conditions.

Pressure readings should therefore be evaluated together with the operating status of the HVAC system.

Monitoring HEPA filter pressure drop

Differential pressure gauges are widely used to monitor resistance across HEPA filters.

One pressure tap is installed upstream of the filter and another downstream.

As air passes through the filter media, resistance creates a measurable pressure difference.

As dust and particles accumulate during operation, filter resistance generally increases. Monitoring this trend provides useful information for maintenance planning.

When a new HEPA filter is installed, its initial pressure drop should be recorded at normal operating airflow. This provides a baseline for future comparison.

However, a high differential pressure does not automatically mean that the HEPA filter has failed.

Increased airflow, filter loading or blocked pressure tubing can all influence the reading.

Similarly, a low pressure drop does not prove that the filter remains effective. Filter damage, poor gasket sealing or bypass leakage may reduce resistance while compromising particle-retention performance.

HEPA filter condition should therefore be evaluated using differential pressure together with integrity or leakage testing and airflow measurements.

AHU and HVAC applications

Air-handling units commonly include several filtration stages such as prefilters, intermediate filters and fine filters. Some systems may also incorporate HEPA filtration.

Each filtration stage has its own initial pressure drop and recommended final resistance.

The same gauge range should not automatically be used for every filter.

If the measuring range is too wide, meaningful changes may be difficult to observe. If the range is too narrow, the instrument may operate near or beyond full scale.

Pressure taps must be installed correctly upstream and downstream of the filtration stage being monitored.

Pressure tubing should be protected against leaks, kinks, blockages and condensation.

After a new filter has been installed, the initial pressure drop should be recorded at normal operating airflow.

Trend-based monitoring allows factories to move toward condition-based maintenance rather than relying only on fixed replacement schedules.

Applications on cleanroom equipment

Differential pressure gauges can also be installed on Dynamic Pass Boxes, Air Showers, Laminar Air Flow units, Fan Filter Units, Dispensing Booths, Sampling Booths and HEPA Boxes.

On dispensing booths and LAF units, gauges commonly monitor HEPA filter resistance.

On a Dynamic Pass Box, a differential pressure gauge may monitor filter pressure drop or pressure inside the chamber.

On AHUs with several filtration stages, individual gauges can be installed across each filter stage to make maintenance monitoring easier.

Because airflow rate, filter area and design resistance differ between equipment types, the gauge range should be selected using actual equipment data.

Common differential pressure ranges

For room-pressure monitoring, ranges such as 0–30 Pa, 0–60 Pa, 0–100 Pa and 0–125 Pa may be considered.

Where both positive and negative pressures need to be displayed, bidirectional ranges such as -30 to +30 Pa or -60 to +60 Pa may be suitable.

For HEPA filters, LAF units, dispensing booths, HEPA Boxes and other filtered-air equipment, ranges such as 0–250 Pa, 0–500 Pa, 0–750 Pa or 0–1,000 Pa may be considered depending on design resistance.

These values are reference ranges rather than universal requirements.

Final selection should be based on expected operating pressure, filter data and required reading resolution.

The widest available range is not necessarily the most suitable choice.

Mechanical or digital differential pressure gauge

Mechanical differential pressure gauges are suitable where simple local indication is sufficient.

They are easy to read and normally do not require an electrical power supply for their basic display function.

Digital gauges and differential pressure transmitters are more suitable where continuous monitoring, alarms or data transmission are required.

Depending on the model, outputs may include 4–20 mA, 0–10 V, relay contacts or communication protocols.

For routine visual inspections, a mechanical gauge may provide a simple and economical solution.

For critical pressure points requiring alarms, trend monitoring or central-system integration, digital instruments generally provide greater functionality.

Selecting a supplier in Tan Duc Industrial Park

A suitable supplier should first determine where the differential pressure gauge will be installed and what it is intended to monitor.

For cleanroom room-pressure applications, the supplier should understand pressure cascades, airlocks, room tightness and supply-return airflow balance.

For filter applications, the supplier should consider initial pressure drop, recommended final resistance, operating airflow and filter characteristics.

Selecting an instrument only according to dial size or purchase price may result in an unsuitable measuring range and poor measurement usefulness.

Vietnam Cleanroom Equipment, also known as VCR Cleanroom, supplies differential pressure gauges and other cleanroom equipment to cleanroom contractors, MEP companies, system integrators and industrial factories.

Products are selected according to actual application, measuring range, operating conditions and project-documentation requirements.

Vietnam Cleanroom Equipment can also support contractors with related equipment such as Pass Boxes, Air Showers, FFUs, HEPA Boxes, HEPA filters, Laminar Air Flow units and dispensing booths, supporting better equipment coordination within cleanroom projects.

Calibration and commissioning

Calibration is particularly important where differential pressure is treated as a monitored or controlled parameter.

A calibration certificate should clearly identify the instrument model, serial number, measuring range, calibration points and measurement errors.

A manufacturer's quality certificate does not necessarily replace an individual calibration certificate when measurement traceability is required.

Before commissioning, the contractor should verify the model, range, engineering unit, mounting position, pressure-port connections and zero indication.

For digital instruments, the power supply, output signal, alarm thresholds, display and connection to the control system should also be tested.

Even a calibrated gauge may provide an incorrect field reading if the pressure tubing leaks, becomes blocked, contains condensation or is connected incorrectly.

Commissioning should therefore evaluate the complete measuring loop rather than only the gauge itself.

Frequently asked questions

Where can factories in Tan Duc Industrial Park buy differential pressure gauges?

Factories should choose a supplier with practical experience in cleanrooms and HVAC systems that can support range selection, accessories, installation methods and calibration documentation. Vietnam Cleanroom Equipment supplies differential pressure gauges to factories and cleanroom contractors serving projects in Tan Duc Industrial Park.

Can a room-pressure gauge be used across a HEPA filter?

Only if its measuring range and maximum pressure limit are suitable. Room-pressure applications normally require considerably lower ranges than HEPA filter resistance monitoring.

Can differential pressure determine when a HEPA filter should be replaced?

Differential pressure is an important indicator of filter resistance, but it should not be the only replacement criterion. Airflow, manufacturer recommendations, leakage testing and overall filter condition should also be evaluated.

Is a gauge defective if it does not return to zero?

Not necessarily. Both pressure ports should first be exposed to equal pressure. The pressure tubing, condensation, mounting position and zero adjustment should then be checked.

Can a differential pressure gauge determine cleanroom classification?

No. A differential pressure gauge only measures pressure difference. Cleanroom classification is determined through airborne particle concentration measurements and other applicable tests.

Differential pressure gauge consultation for Tan Duc Industrial Park

When requesting technical advice or a quotation, factories and contractors should provide the installation location, expected pressure range, display type, signal requirements, quantity and required technical documentation.

Vietnam Cleanroom Equipment supplies differential pressure gauges for cleanrooms, AHUs, HVAC systems, HEPA filters, Dynamic Pass Boxes, dispensing booths, LAF units and other controlled-air equipment for projects in Tan Duc Industrial Park.

Correctly defining the application from the beginning helps select the appropriate model, minimise installation changes and improve commissioning, project acceptance and long-term maintenance.