100% Original Samson 3730 Electropneumatic Positioner with Hart Communication 3730-3

• Customization: Available
• Customized: Customized
• Certification: CE
• Model NO.: SAMSON 3730
• Power: Pneumatic
• Pressure: Low Pressure
• Brand: Samson
• Work Temperature: Normal Temperature
• Material: Aluminum
• Place of Origin: China
• Brand Name: Samson
• Customized Support: OEM, ODM
• Warranty: 1 Year
• Model Number: 3730-3
• Body Materials: Aluminium Extrusion
• Supply Media: Air CO2
• Input Signal: 4-20mA DC
• Nominal Trave,Adjustable: 3.6 to 30 mm
• Signal Range: 4 to 20 Ma
• Minimum Current: 3.6 Ma for Display
• Supply Air: 1.4 to 6 Bar (20 to 90 Psi),
• Hysteresis: ≤ 0.3 %
• Temperature: - 20 to +80 °C
• Supply Voltage: 12 to 30 V DC
• Transport Package: Original and New
• Specification: 30X30X30 cm
• Trademark: SAMSON
• Origin: China
• Production Capacity: 1000 Piece/Year
• Package Size: 30.00cm * 30.00cm * 30.00cm
• Package Gross Weight: 4.000kg

Product Description

Product Description

Samson 3730-3

In the landscape of industrial process control, valve positioners serve as the "brain" of control valve systems, bridging the gap between digital control signals and mechanical valve movement. Among the industry's most reliable and versatile offerings, the Samson 3730-3 stands out as a smart electro-pneumatic valve positioner designed to optimize the performance of linear and rotary control valves. Developed by Samson Controls, a global leader in process control solutions with over a century of engineering expertise, the 3730-3 is engineered to meet the demanding requirements of modern industries—from oil and gas to pharmaceuticals, power generation, and chemical processing.
Unlike basic positioners, the Samson 3730-3 integrates advanced digital technology, robust mechanical design, and flexible communication capabilities to deliver precision, reliability, and ease of use. Its core mission is to ensure that control valves respond accurately to input signals from distributed control systems (DCS) or programmable logic controllers (PLCs), even in harsh operating environments. By minimizing positioning errors, reducing energy consumption, and enabling remote monitoring, the 3730-3 plays a critical role in enhancing process stability, product quality, and operational efficiency.

1. Product Overview of Samson 3730-3

1.1 Samson Controls: A Legacy of Innovation
To contextualize the 3730-3, it is essential to first recognize Samson Controls' role in the process control industry. Founded in 1907 in Frankfurt, Germany, Samson has grown into a global enterprise specializing in control valves, actuators, and positioners. The company's commitment to innovation is evident in its portfolio of products, which are designed to address evolving industry needs—such as stricter environmental regulations, increased demand for digitalization, and the need for reliable performance in extreme conditions.
Samson's expertise in fluid dynamics, materials science, and digital control systems has positioned it as a trusted partner for industries where precision and safety are non-negotiable. The 3730-3, launched as part of Samson's "Smart Positioner" lineup, builds on this legacy by combining time-tested mechanical design with cutting-edge digital features.
1.3 Product Variants and Customization Options
Samson offers several variants of the 3730-3 to address specific industrial needs:
3730-3 Standard: The base model, designed for general-purpose applications with analog (4–20 mA) and HART communication.
3730-3 Fieldbus: Equipped with Foundation Fieldbus or Profibus PA for integration into digital control networks, enabling advanced diagnostics and remote configuration.
3730-3 Ex: Certified for hazardous areas (ATEX Zone 1/21, IECEx Zone 1), featuring explosion-proof enclosures and intrinsic safety.
3730-3 Low-Temp/High-Temp: Modified with specialized materials (e.g., silicone seals for low temperatures, heat-resistant plastics for high temperatures) to operate in extreme thermal conditions.
Additionally, Samson provides customization options such as:
Alternative pressure ranges (e.g., 0.1–0.6 bar for small actuators).
Specialized coatings (e.g., nickel-plated enclosures for corrosive environments).
Custom cable entries (e.g., M20, NPT) to match site-specific wiring standards.

3. Operating Principles of Samson 3730-3

The Samson 3730-3 operates on the principle of electro-pneumatic conversion, where an electrical input signal is translated into a pneumatic output that drives the valve actuator. This process involves three core stages: signal reception and processing, feedback monitoring, and pneumatic output adjustment. Below is a detailed breakdown of each stage.
3.1 Signal Reception and Processing
The 3730-3 begins by receiving an input signal from a higher-level control system (e.g., DCS). This signal can be either analog (4–20 mA) or digital (via HART, Foundation Fieldbus, or Profibus PA).
Analog Signal Processing: For a 4–20 mA signal, the positioner's internal analog-to-digital converter (ADC) converts the continuous electrical current into a digital value. This digital value is then mapped to a desired valve position (e.g., 4 mA = 0% open, 20 mA = 100% open for linear valves).
Digital Signal Processing: For digital signals (e.g., HART), the positioner decodes the signal to extract not only the desired position but also additional commands—such as parameter adjustments, diagnostic requests, or calibration instructions. HART 7, the latest version of the protocol, enables two-way communication, allowing the positioner to send real-time data (e.g., current valve position, temperature) back to the control system.
Once the desired position is determined, the positioner's microcontroller compares it to the actual valve position (obtained via the feedback mechanism, discussed in Section 3.2). This comparison generates an "error signal"—the difference between the desired and actual positions.
3.2 Feedback Mechanism: Ensuring Precision
The feedback mechanism is critical to the 3730-3's accuracy, as it provides real-time data on the valve's current position. Samson uses two primary feedback technologies, depending on the valve type:
3.2.1 Non-Contact Hall-Effect Sensors (Linear Valves)
For linear valves (e.g., globe valves with linear stem movement), the 3730-3 uses a non-contact Hall-effect sensor. This sensor consists of a magnet attached to the valve stem and a stationary Hall-effect transducer mounted in the positioner. As the stem moves up or down, the magnet's position relative to the transducer changes, altering the magnetic field detected by the transducer.

Specification

Input Signal	Analog: 4–20 mA DC; Digital: HART 7, Foundation Fieldbus, Profibus PA
Output Signal	Pneumatic: 0.2–1.0 bar (3–15 psi) for single-acting actuators; 0.2–1.0 bar (3–15 psi) for double-acting actuators
Positioning Accuracy	±0.5% of full scale (FS) for linear valves; ±1% FS for rotary valves
Response Time	<0.5 seconds (for 90% step response with standard actuators)
Operating Temperature Range	-40°C to +80°C (-40°F to +176°F); optional extension to -50°C to +120°C
Protection Class	IP66/IP67 (dust-tight, waterproof); ATEX, IECEx, and certifications for hazardous areas
Power Supply	24 V DC (from DCS/PLC); optional 12 V DC for specialized applications
Mounting Compatibility	Direct mounting to Samson actuators (e.g., 3277, 3520) or ISO 5211-compliant actuators

Company Profile

KeRui (Weifang) Automation Equipment Co. Ltd. Has maintained a cooperatve relationship with Rosemount for 15 years, and our purchase quantity has reached 20,000 units.

We supplied the tuning fork level gauge to the Rosemount factory and have been well received by the Beijing factory. We have cooperated with Yokowaga and maintained a cooperative relationship for 8 years, and our purchase quality has reached 7000 units.

The companies we have cooperated with:

1. Awarded "Outstanding Supplier by Yanchang Petroleum in 2008

2. In December 2012, our company was awarded the "Excellent Equipment Service Award" for the expansion project of units 6 and 7 of the Guangdong Guohua Yuedaishan Power Plant

3. Awarded "Outstanding Supplier by Yaxing Group in 2013

4.200 transmitters for Haihua Group's ethylene debottlenecking transformation project in 2015.

5. In 2018, we were rewarded as a National Nuclear Power Instrumentation Industry Measurement and Testing Alliance member.

6.160 transmitters and 20 electric autuators for the Shandong Laigang Yongfeng Steel expansion project in 2019

7.In 2022, Jinneng Chemical (Qingdao) Co., Led/ Jinneng 2x450,000 tons/ year high-performance polypropylene project (newly built) equipped 460 transmitters from our company.

8. In 2022, Shandong Qinghe Chemical Technology Co., Ltd.s hydrogen peroxide method epoxy propane device and supporting hydrogen peroxide device expansion project used 253 pressure transmitters.

9.In 2022, the Wanhua Chemical HTN project NPG installed 320 transmitters and 50 sets of valve positioners.

Our Service

OEM / ODM services
To meet the user diversified requirement, Holykell have established a set of customer service and technical support system with OEM / ODM order as the center, and responded and Handle the customer's requirements in a timely manner to ensure accurate delivery time and product quality.
Order services
Fastest reply:Professional sales engineers 7/24 online services
Payment terms:T/T ,Western union, Paypal, Credit Card, L/C others
Fast delivery: within 24 hours release the cargo (normal spec.), Customized 7-12 days after payment .
 
MAINTENANCE & AFTER-SALES SERVICES
Customer Feedback:  Sales engineers and technical engineers will be one-on-one service for you to exclude all obstacles when use our sensors.
Warranty period: 12 months
Product life-long maintenance: Holykell can provide you with the maintenance of the whole life of the sensors

Packaging & Shipping

FAQ

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Q1: How long will it take you to give me the reply?

A: We will reply to you as soon as we see the information

Q2: What is the delivery time?

A: Our delivery time is within 3- 7 days after we get your payment; for large qty mass orders, the time should be confirmed again for you

Q3: How about your package? 

A: Do not worry about the package. We have a lot of experience in packing, and all our packages are wooden case packages.

Q4: How about the payment terms?

A: You can choose T/T.

Q5: Do you provide samples? 

A: Yes, we have materials in stock to help you get the samples as soon as we can.

Q6: What is the MOQ?

A:1PC.

Q7: Can I get a lower price if I order large quantities? 

A: Yes, cheaper prices with larger orders.

Q8: Why choose us?

We have a perfect customization, not only to provide you with quality products, but also to have a professional customer service team available at any time to provide you with support. We pay more attention to establishing a long-term cooperative relationship with you to achieve continuous business growth.

Q9: How can we guarantee quality?

We have strict requirements on the quality of our products, and we will conduct a final inspection of our products when we ship them.