Bray Series 70 Electric Actuator

Overview

The Bray Series 70 is a compact quarter-turn electric actuator designed to automate butterfly valves, ball valves and other rotary valves that travel through ninety degrees. Bray built the family for on/off duty, modulating duty and network control, and the range covers output torques from 300 lb-in (34 Nm) up to 18,000 lb-in (2,034 Nm). Bray describes the Bray Series 70 as the lowest profile and lightest weight actuator in its class, which matters wherever a valve sits in a tight pipe rack, a crowded plant room or a pit with limited headroom.

Seven Star LLC supplies the Bray Series 70 to plant owners, EPC contractors and maintenance teams across the Sultanate of Oman and the wider GCC. As a trusted supplier with engineering support in Muscat, we help buyers choose the right torque size, voltage and controller, and we match the actuator to the valve that it will drive, so that the package arrives on site ready for installation and commissioning.

Operating Principle

Inside the Bray Series 70 enclosure, a reversible single-phase motor drives a train of spur gears that feeds a self-locking worm shaft and worm gear. The 120 and 230 VAC versions use a permanent split capacitor induction motor, while the 24 V versions use a permanent magnet brushed DC motor. The worm gear set multiplies motor torque and turns the output drive through a quarter turn. Because the worm drive is self-locking, the valve stays exactly where the actuator stopped it, even when line pressure or flow tries to push the disc or ball back toward another position. No brake and no holding current are needed to keep the valve in place.

Travel on the Bray Series 70 is controlled by two cams on the indicator shaft. Each cam trips a mechanical SPDT limit switch at the open and closed ends of travel, which stops the motor and gives a dry contact for remote indication. Mechanical travel stop bolts sit behind the electrical limits and prevent over-travel during manual operation, allowing five degrees of over-travel. On modulating units, the Servo NXT controller compares the command signal with the position feedback from a gear-driven potentiometer and drives the motor in short steps until the valve reaches the requested position. The result is a simple, robust electromechanical drive that suits clean water, chilled water, air, gas and many process duties.

Engineering Design of the Bray Series 70

The Bray Series 70 housing is ASTM B85 pressure die-cast aluminum with a polyester powder coat, and a Nylon 11 coating is available as an option for more aggressive atmospheres. Bray designed the actuator like a junction box: once the cover is removed, the terminal strip, the cams and the switch assemblies are all directly reachable without having to work around other parts. Captive stainless steel cover bolts sit outside the O-ring sealing area, so the cover can be removed and replaced without losing hardware. Most models are rated NEMA Type 4, Type 4X, IP65 and IP67, except that the largest S70-130/131 and S70-180/181 units are not rated IP67.

Two conduit entries on the Bray Series 70 keep power and control wiring separate: 2 × 1/2 inch NPT or 2 × M20 on the S70-E03 to S70-E08 sizes, and 2 × 3/4 inch NPT or 2 × M25 on the S70-E12 to S70-180 sizes. A declutchable handwheel is standard on every model. Pulling the handwheel out exposes a yellow stripe on the shaft, engages manual drive and opens a switch that interrupts power to the motor, which protects the operator. An Oldham coupler corrects small misalignment between valve and actuator, and the mounting interface follows ISO 5211 so that the actuator can be fitted directly onto standard valve top flanges with the right drive bushing.

Key Features

The following points summarize why engineers select the Bray Series 70 for quarter-turn valve automation:

• Output torque from 300 lb-in to 18,000 lb-in (34 to 2,034 Nm) at 120 and 230 VAC, with 24 V versions rated at 600, 800, 2,000 and 5,000 lb-in.
• Low profile, light weight die-cast aluminum enclosure with a corrosion, impact and ultraviolet resistant polyester powder coat.
• A large, high visibility position indicator dome, colored yellow for open and red for closed, showing valve position through the full stroke.
• Patented green and red limit switch cams that can be set by finger or with a screwdriver, with no special tools required.
• Two SPDT mechanical limit switches as standard, with room for up to six switches in total and optional torque switches.
• A standard declutchable manual override with a motor cut-out switch for safe hand operation during maintenance or power loss.
• Self-locking chromoly worm and aluminum bronze worm gear that hold the valve in position without a brake.
• Optional Servo NXT modulating controller, On/Off NXT controller, EtherNet/IP communication, 5 W PTC heater and 10 kOhm potentiometer.

Controls and Configuration Options

The standard Bray Series 70 on/off control for 120 and 230 VAC units is the interposing relay board, which lets a plant control system open and close the valve with simple contacts. For 24 VAC/VDC supplies, the On/Off NXT controller provides the same function. Where the valve must throttle, the Servo NXT controller accepts configurable 4-20 mA, 0-10 V, 2-10 V or 0-5 V command signals and can retransmit the valve position as 4-20 mA, 0-10 V or 0-5 V. It offers one touch automatic calibration, adjustable proportional band and dead band, automatic pulsing mode for fine positioning, self diagnostics, action on loss of command signal and go to position commands. A Servo NXT EtherNet/IP version connects the actuator directly to plant networks.

The Bray Series 70 duty rating follows EN 15714-2: Class A for on/off applications and Class C for modulating applications. The ambient operating range is -29 °C to +65 °C (-22 °F to +150 °F). The motor insulation is Class F on the AC versions, with a thermal trip that protects the winding, while the 24 V motor is Class B and fused. Standard 1/4-turn speeds are about 30 seconds on most AC units and 60 seconds on the 24 V units, while the large S70-130/131 and S70-180/181 sizes run at about 110 seconds.

Industrial Applications

In Oman and the GCC, the Bray Series 70 is a practical choice for water and wastewater treatment plants, pumping stations, desalination pretreatment, district cooling plants, commercial HVAC systems and data center cooling loops, where many butterfly valves need dependable remote operation. The low profile helps in valve chambers, and the weatherproof enclosure suits outdoor skids exposed to sun, dust and humidity in Muscat, Sohar, Duqm and Salalah. Bray also lists oil and gas, chemical and petrochemical, power generation, food and beverage, mining and metals, and pulp and paper among the industries that use the Series 70.

Seven Star LLC supplies the Bray Series 70 as a stand-alone actuator or as part of an automated valve package. A typical pairing is a Bray Series 30/31 resilient-seated butterfly valve for water service. For heavier process duty, buyers often compare the Bray Series 70 with a Limitorque LQI quarter-turn electric actuator, and for high pressure process isolation it can be considered alongside a XOMOX Type 800 high-performance butterfly valve package. Our engineering team in Muscat checks valve torque, voltage, control signal and environment before quoting, so the Bray Series 70 selected for your project is sized correctly the first time.

Technical Specifications

The data below summarizes the Bray Series 70 electric actuator according to the Bray datasheet and technical sales manual. Please confirm the exact model and options with our team before ordering.

How to Order

To order the Bray Series 70 electric actuator for a project in Oman or the GCC, send a formal RFQ to Seven Star LLC with the valve type and size, required torque, supply voltage, control mode and any network or hazardous area requirement. Our instrumentation division in Muscat will confirm the correct size and part number, check availability and lead time, and send a complete technical offer. The datasheet and technical sales manual are available for download on this page, and our engineers are ready to support every Bray Series 70 installation from selection through commissioning.