Honeywell STF725 Flange Mounted Transmitter
Model：STF725-X1AC4A-J1F-A-AHS-11S-A-00A0
Manufacturer: Honeywell
Size: 50*50*45CM
Detail Specification: Differential Pressure Transmitter
Comment:Carton
Shipping Weight: 20Kg
Estimated Lead Time: 12 Weeks
Payment：T/T
HS CODE：9026201090
product details
Honeywell STF725 Flange Mounted Transmitter
Product Overview
The Honeywell STD735 Differential Pressure Transmitter is a high-performance DP measurement instrument from the SmartLine® ST700 family. Engineered for critical process applications, the Honeywell STD735 combines advanced piezoresistive sensor technology with on-chip static pressure and temperature compensation, delivering exceptional measurement accuracy and long-term stability across a wide range of process conditions-2.
The Honeywell STD735 belongs to the SmartLine® product family, fully tested and compliant with Experion® PKS, providing the highest level of compatibility assurance and seamless integration capabilities for modern automation systems-2. As a differential pressure transmitter, the STD735 is ideal for critical process loops and high-value applications such as custody transfer, energy and material balances, furnace combustion airflow rate measurement, and hydrostatic tank gauging-2.
Core Sensor Technology
The Honeywell STD735 is designed around a high-performance piezoresistive sensor that integrates multiple sensing elements within a single platform. This “three-in-one” sensor architecture combines differential pressure sensing, static pressure measurement, and temperature sensing, delivering a fully compensated output signal that maintains exceptional performance across varying operating conditions-6.
The STD735 features ion-implanted silicon technology that automatically corrects errors caused by process temperature variations and static pressure changes. This advanced compensation ensures that Honeywell STD735 transmitters deliver consistent, reliable measurements even in challenging industrial environments.
Technical Specifications
Performance Characteristics
| Parameter | Specification |
| Model Series | SmartLine ST700 |
| Model | STD735 Differential Pressure |
| Pressure Range | –100 to +100 psi (–7.0 to +7.0 bar) |
| URL (Upper Range Limit) | 100 psi (7.0 bar) |
| LRL (Lower Range Limit) | –100 psi (–7.0 bar) |
| Minimum Span | 1 psi (0.07 bar) |
| Maximum Span | 100 psi (7.0 bar) |
| Accuracy (Standard) | ±0.065% of calibrated span |
| Accuracy (Optional) | ±0.05% to ±0.04% of span |
| Stability | ±0.020% of URL per year for up to 10 years |
| Rangeability (Turndown Ratio) | Up to 100:1 |
| Response Time | As fast as 100 ms |
| Static Pressure Rating (MAWP) | 4,500 psi (310 bar) |
The Honeywell STD735 delivers standard accuracy of ±0.065% of calibrated span, with enhanced accuracy options available for applications requiring tighter measurement tolerances-6. Long-term stability is rated at ±0.020% of URL per year for up to 10 years, ensuring consistent performance over extended operational periods-5. The STD735 offers a turndown ratio of 100:1, providing exceptional application flexibility and reducing the need to stock transmitters with multiple ranges.
Electrical Specifications
| Parameter | Specification |
| Output Signal | 4–20 mA DC, two-wire |
| Communication Protocol | HART® version 7.0 (standard); FOUNDATION Fieldbus; DE protocol (optional) |
| Supply Voltage | 10.5 to 42.4 VDC |
| Turn-on Time | 2.5 seconds |
| Supply Voltage Effect | 0.005% of span per volt |
| Load Resistance | 250–600 Ω (HART, typical) |
| Polarity Protection | Insensitive to polarity connection |
Honeywell STD735 transmitters support bidirectional communication and configuration via HART protocol, enabling remote monitoring, diagnostics, and parameter adjustments without interrupting process operations. The STD735 can replace virtually any 4–20 mA transmitter currently on the market, offering seamless retrofitting capabilities-33.
Environmental and Mechanical Specifications
| Parameter | Specification |
| Ambient Temperature Range | –40°C to +85°C |
| Process Temperature Range | –40°C to +110°C (meter body) |
| Storage Temperature Range | –50°C to +120°C |
| Enclosure Rating | IP66, IP67 standard; IP68 optional |
| Housing Material | Polyester powder-coated aluminum (low-copper), meets NEMA 4X and NEMA 7 |
| Process Head Material | 316 Stainless Steel; Carbon Steel (Zinc-plated); Hastelloy® C-276 |
| Barrier Diaphragm Material | 316L Stainless Steel; Hastelloy® C-276 |
| Fill Fluid | Silicone Oil DC200; CTFE (Fluorinated Oil) optional |
| Process Connection | 1/4″ NPT female (standard); 1/2″ NPT adapter optional |
| Electrical Connection | 1/2″ NPT conduit entry; M20 optional |
| Net Weight | Approximately 4.1 kg |
| Static Pressure Tolerance | 31.5 MPa |
The Honeywell STD735 is designed for durability in harsh industrial environments. The housing is made of pure polyester powder-coated low-copper aluminum alloy, meeting NEMA 4X (waterproof) and NEMA 7 (explosion-proof) standards. A stainless steel housing option is also available-7-32.
Materials of Construction
| Component | Standard Material | Optional Materials |
| Process Heads | 316 SS | Carbon Steel, Hastelloy C-276 |
| Barrier Diaphragms | 316L SS | Hastelloy C-276, Monel, Tantalum |
| O-Ring Gaskets | PTFE (Teflon, glass-filled) | Viton®, Graphite |
| Meter Body Bolting | Carbon Steel (Zinc-plated) | 316 SS, NACE A286 SS, Super Duplex |
| Vent/Drain Valves | 316 SS | Hastelloy C-276 |
Complete Model Number Examples
The Honeywell STD735 ordering code allows extensive customization. Below are actual complete part numbers:
STD735-E1AC4AS-1-A-AHS-11S-A-10A0-F1.02-0000 – 316 SS wetted materials, Silicone Oil 200 fill, 1/4″ NPT process connection, HART output, standard display with internal buttons
STD735-E1AC4AS-1-0-AHS-11S-A-10A0-00-0000 – Standard configuration, polyester powder-coated aluminum housing, 1/2″ NPT electrical connection, carbon steel mounting bracket
STD735-E1HC4AS-1-C-CH0-11S-B-00A0-00 – High-static pressure configuration, custom approvals, enhanced accuracy calibration
STD735-J1HS4AS1-11S-A-10A0-F1-F5 – Alternative configuration with specialized wetted materials and additional options-
STD735-E1AN4AS-1-C-EHT-11C-B-10A6-F1,FE,02 – Custom configuration with high-temperature fill fluid and enhanced diagnostics-14
Model Number Code Breakdown
| Position | Code Element | Options for STD735 |
| 1 | Model | STD735 (Differential Pressure) |
| 2 | Wetted Materials | E (316 SS/316L SS/Hastelloy C-276); J (Other) |
| 3 | Fill Fluid | 1 (Silicone Oil 200); 2 (CTFE Fluorinated Oil) |
| 4 | Process Connection | A (None, 1/4″ NPTF std); G (1/2″ NPT); H (Other) |
| 5 | Head Material/Bolts | C (Carbon Steel); 0 (Other) |
| 6 | Vent/Drain Type | 4 (Dual Ended, Standard Vent) |
| 7 | Gasket Material | A (Teflon/PTFE) |
| 8 | Static Pressure Rating | S (Standard, 4,500 psig) |
| 9 | Head Orientation | 1 (Standard, High Left/Low Right) |
| 10 | Approvals | A (FM); G (NEPSI); 0 (None) |
| 11 | Housing/Electrical | A (Aluminum, 1/2″ NPT) |
| 12 | Output/Protocol | H (4–20 mA with HART 7) |
| 13 | Customer Interface | S (Standard w/ internal buttons) |
| 14 | Display | A (None); S (Standard LCD) |
| 15 | Language | 1 (English, Russian) |
| 16 | Application Software | 1 (Standard Diagnostics) |
| 17 | Output Limits/Failsafe | 1 (Disabled, High>21.0 mA) |
| 18 | Configuration | S (Factory Standard) |
| 19 | Accuracy/Calibration | A (Standard, Single Calibration) |
| 20 | Mounting Bracket | 1 (Angle Bracket, Carbon Steel) |
| 21 | Customer Tag | 0 (None) |
| 22 | Conduit Plugs | A0 (None) |
| 23 | Additional Options | 00 (None) |
| 24 | Factory Identification | 0000 |
Display and User Interface
The Honeywell STD735 features a modular alphanumeric LCD display with the following capabilities-6:
Display size: 2 lines, 6 digits PV (9.95H x 4.20W mm), 8 characters
Position adjustments: 0°, 90°, 180°, and 270° rotatable
Configurable screens: Four programmable display screens
Measurement units: Pa, kPa, MPa, kg/cm², torr, atm, inH₂O, mH₂O, bar, mbar, inHg, ftH₂O, mmH₂O, mmHg, psi
Square root output indication: Calculated flow (square root) value display
Write protect indication: Standard
Languages: English, Russian
External configuration buttons: Zero, span, and configuration capability without removing housing cover
The display module is modular and can be added or removed in the field. Internal configuration buttons enable basic device setup including range/engineering unit selection, loop test, loop calibration, and zero/span setting-8.
Key Features
Diagnostic Capabilities
Honeywell STD735 transmitters offer comprehensive on-board diagnostic capabilities that provide digital access to device health monitoring. These diagnostics deliver advanced warning of possible failure events, minimizing unplanned shutdowns and reducing overall operational costs. The self-diagnostic function continuously monitors sensor integrity, electronics performance, and communication status-6.
Safety and Compliance
The Honeywell STD735 incorporates an integral dual seal design based on ANSI/NFPA 70-202 and ANSI/ISA 12.27.0 standards, ensuring maximum safety in process applications-6. Key certifications include:
SIL 2/3 compliance – full compliance as standard configuration
ATEX explosion-proof and intrinsically safe (Ex d IIC T5/T6, Ex ia IIC T4/T5/T6)
FM approval – explosion-proof, intrinsically safe, non-incendive, dust-ignition proof
CSA certification
CE marking
NEPSI certification for Chinese hazardous area requirements
Overpressure Protection
The STD735 provides world-class overpressure protection as a standard configuration. The static pressure rating is 4,500 psi (310 bar) maximum allowable working pressure (MAWP), though this can vary depending on the approval agency and transmitter materials of construction-5.
Modular Design
Honeywell STD735 pressure transmitters feature a fully modular construction that enables easy field maintenance and configuration-6:
Replaceable sensor module – removable without de-pressurizing the process
Replaceable electronics module – field-swappable without recalibration
Optional display module – add or remove in the field
Interchangeable housing options – explosion-proof and weatherproof variants
This modular design eliminates the need to stock transmitters with multiple ranges or electronic modules, allowing users to redefine range or replace electronics without purchasing additional transmitters.
Configuration Tools
The Honeywell STD735 can be configured using multiple methods:
External two-button configuration – suitable for all electrical and environmental requirements, enabling configuration of all basic parameters-6
Internal two-button configuration – accessible when display module is fitted
MCT202 Multi-Protocol Communicator – field configurable for HART transmitters
SCT3000 Configuration Toolkit – PC-based configuration for DE protocol transmitters
Field Device Manager (FDM) – manages HART and Fieldbus device configurations
HART DTM – organizes parameters under Configuration, Monitoring, Diagnostics, and Maintenance
Applications
The Honeywell STD735 is ideal for a broad range of differential pressure measurement applications:
Flow Measurement
Orifice plate flow measurement (furnace combustion airflow rate)
Venturi and nozzle flow monitoring
Annubar and pitot tube flow systems
Custody transfer flow applications
Level Measurement
Hydrostatic tank level gauging
Boiler drum level monitoring
Open channel flow measurement
Interface level detection
Critical Process Applications
Energy and material balances
Refinery distillation column pressure monitoring
Chemical reactor differential pressure
Filter monitoring and control
Industrial Processes
Water and wastewater treatment
Pulp and paper manufacturing
Food and pharmaceutical industries
Power generation
Installation Considerations
The Honeywell STD735 is designed for flexible installation:
Mounting: 2-inch pipe mounting using angle bracket (carbon steel or stainless steel) or flat bracket. The bracket can be installed in almost any position and is designed for both vertical and horizontal pipe mounting.
Process connections: 1/4″ NPT female standard, with 1/2″ NPT adapter available
Electrical connections: 1/2″ NPT conduit entry standard; M20 optional
Wiring: Accepts up to 16 AWG (1.5 mm diameter)
For optimal performance, mount the transmitter in a location with minimal vibration, ensure ambient temperature remains within specified limits, use appropriate conduit seals for hazardous area installations, and allow sufficient access for external zero/span adjustment buttons.
Ordering and Availability
Honeywell STD735 differential pressure transmitters are available through authorized Honeywell distributors worldwide. Standard lead times range from 6–8 weeks for standard configurations. Custom configurations with specialized materials, extended warranties, or enhanced accuracy options may require additional lead time. Extended warranty up to 15 years is available upon request.
For pricing, availability, and configuration assistance, contact your local Honeywell representative or authorized distributor. Stock configurations may be available for immediate shipment.
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