QFF3 Three Valve Manifold

QFF3 Three Valve Manifold

The SIYelectric QFF3 Three Valve Manifold is designed for differential pressure transmitter installation, isolation, equalizing, bleeding, and calibration in industrial process measurement systems.

The QFF3 three valve manifold typically integrates two block valves and one equalizing valve into one compact valve body. The two block valves isolate the high-pressure and low-pressure sides from the process line, while the equalizing valve balances pressure across the transmitter during zero adjustment, commissioning, calibration, or maintenance.

It is commonly used with differential pressure transmitters, pressure transmitters, pressure gauges, and other process instruments for flow measurement, level measurement, filter differential pressure monitoring, pressure difference measurement, and general process control applications.

Applications

Oil & Gas Industry

Differential pressure and process pressure monitoring
Used in drilling, production, pipeline transmission, gas processing, and refinery systems where DP transmitters are applied for flow, level, or pressure difference measurement.

Flow measurement support
Suitable for DP flow measurement loops using orifice plates, flow nozzles, venturi tubes, and other primary flow elements.

Isolation, equalizing, and venting
The QFF3 three valve manifold allows operators to isolate both pressure sides, equalize pressure across the transmitter, release trapped pressure, and perform zero checks or calibration more safely in high-pressure service.

Chemical and Petrochemical Plants

Process differential pressure measurement
Applied in reactors, pumps, filters, distillation columns, storage tanks, and chemical pipelines where stable differential pressure or process pressure monitoring is required.

Safer maintenance in demanding media
The manifold helps isolate instruments from corrosive, toxic, flammable, high-pressure, or high-temperature media before inspection, replacement, or calibration.

Power Generation

Steam and water systems
Used in boiler systems, turbine auxiliary systems, feedwater lines, condensate systems, and steam pipelines where DP transmitters are used for flow, level, and pressure difference measurement.

Instrument protection and calibration
The three valve structure helps protect the transmitter during commissioning, shutdown, zero adjustment, and routine calibration work.

Pharmaceutical and Biotechnology

Clean utility and auxiliary process lines
Suitable for auxiliary differential pressure measurement in water systems, clean utility lines, filtration skids, fermentation equipment, mixing systems, and process skids.

Clean process isolation
For hygienic or sanitary applications, material selection, connection type, sealing structure, and surface requirements should be selected according to the actual process medium and cleaning requirements.

Water Treatment and Distribution

Flow and differential pressure monitoring
Used in filtration systems, pumping stations, membrane systems, treatment equipment, and distribution pipelines to support pressure measurement, flow monitoring, and differential pressure control.

Filter pressure drop measurement
Suitable for monitoring differential pressure across filters, membranes, and treatment units, helping operators identify clogging, fouling, or maintenance requirements.

HVAC Systems

Differential pressure measurement
Applied in chilled water, heating water, air handling units, filter sections, pump systems, and heat exchangers where pressure difference needs to be monitored.

Maintenance isolation
The QFF3 manifold allows technicians to isolate and equalize the transmitter locally, making inspection, zero adjustment, calibration, and replacement more convenient.

Laboratories and Research Facilities

Controlled DP measurement lines
Used in laboratories, test benches, pilot plants, and research systems where gases or liquids require stable differential pressure monitoring.

Compact instrument connection
The manifold body supports transmitter mounting, pressure balancing, isolation, calibration, and pressure line management in experimental or small-scale process systems.

Advantages

• QFF3 three valve structure supports differential pressure transmitter installation and maintenance.
• Two block valves plus one equalizing valve provide safe isolation and pressure balancing across the transmitter.
• Suitable for flow, level, filter, and DP monitoring in process instrumentation loops.
• Compact manifold body helps simplify instrument piping and reduce installation complexity.
• Non-rotating stem design helps reduce seat wear and extends valve service life.
• Improved locking gland structure helps maintain stable stem operation and reliable sealing.
• 100% pneumatic pressure testing before shipment helps verify sealing performance.
• Tested at 1.5 times the design pressure to support reliable operation in demanding industrial applications.
• Hastelloy tip available as standard configuration for improved corrosion resistance and longer service life.
• Precision-machined valve body helps ensure accurate dimensions, smooth operation, and consistent sealing performance.