Masoneilan BR400 High Capacity Volume Booster Relay

Overview

The Masoneilan BR400 is the larger of the two Baker Hughes high capacity volume booster relays, designed for pneumatic control valve applications that need fast stroking. A booster of this kind sits between the output of a positioner or controller and the actuator and repeats the signal pressure at a much higher air flow, so a large diaphragm or piston actuator can fill and exhaust quickly instead of waiting for the small ports of the signal source. The Masoneilan BR400 is listed with a maximum supply Cv of 2.6 and an exhaust Cv of 2.4, roughly double the figures of the BR200, and it is suited to the larger actuator volumes in a plant.

Seven Star LLC is a trusted supplier for Masoneilan and supplies the Masoneilan BR400 to refineries, gas plants, power stations and water utilities across the Sultanate of Oman and the GCC. Our instrumentation team in Muscat helps customers decide whether a BR200 or a BR400 is right for a given actuator size and stroking time, and provides the Baker Hughes datasheet so that connection sizes, temperature limits and air quality requirements can be confirmed before an order is placed.

Operating Principle of the Masoneilan BR400

The Masoneilan BR400 works with a 1:1 ratio between input and output pressure. The input signal pressure acts on the upper diaphragm and produces a force that is opposed by the output pressure acting on the lower diaphragm through the seal plate orifice. When the signal rises, the upper diaphragm is depressed and opens the pilot valve, admitting supply pressure to the output until the output pressure rebalances the forces. When the signal falls, the exhaust valve opens and the output vents until it equals the new signal pressure.

A bypass valve allows a controlled flow of the input signal directly to the output, which gives stable control for small or slow-changing signals. Baker Hughes explains that the dynamic response of the booster can be tuned by adjusting this bypass valve, and that stable operation over a wide range of actuator sizes can be obtained in this way. A locking screw holds the adjustment, so the sensitivity set during commissioning does not drift in service. The BR400 is equally suitable for diaphragm actuators and for piston actuators.

Engineering Design of the Masoneilan BR400

The body and case of the Masoneilan BR400 are aluminium alloy die-castings, the upper and lower diaphragms are chloroprene and polyester, the seal plate, coil spring, plug and bypass valve plug are austenitic stainless steel, and the exhaust seat and plug cap are copper alloy. Assembly hardware is stainless, and the finish is corrosion resistant for use in corrosive atmospheres. Baker Hughes notes that the BR400 is also available in stainless steel for marine and offshore applications. A filter on the supply pressure port protects the pilot from particles in the air supply.

The larger BR400 body is about 127 mm in diameter and weighs approximately 1.4 kg, compared with 0.7 kg for the BR200. Supply and output connections are 1/2 inch NPT or Rc, against 1/4 inch on the smaller relay, and the signal connection is 1/4 inch NPT or Rc. Maximum signal and supply pressure are both 150 psi (10.3 bar). Standard temperature limits are -30 to +83 degrees Celsius, with a low-temperature version for -55 to +60 degrees Celsius and a high-temperature version for 0 to +100 degrees Celsius. Baker Hughes requires clean, dry air with a dew point at least 10 degrees Celsius below the lowest ambient temperature and an oil content below 1 ppm.

Key Features

The following capabilities explain when to select the Masoneilan BR400 rather than the smaller relay:

• Maximum Cv of 2.6 on supply and 2.4 on exhaust for rapid filling and venting of large actuators.
• Built-in bypass valve with a locking screw to adjust sensitivity and dynamic response.
• 1:1 input and output ratio, so the booster repeats the positioner signal without gain.
• Filter on the supply pressure port to protect the pilot from particles in the air.
• 1/2 inch NPT or Rc supply and output ports that suit larger tubing runs.
• Suitable for both diaphragm and piston actuators on rotary and linear valves.
• Corrosion-resistant finish and stainless assembly hardware, with a stainless steel body available for marine service.
• Standard, low-temperature and high-temperature versions from -55 to +100 degrees Celsius.

Industrial Applications

Baker Hughes lists the Masoneilan BR400 for power generation, refining, petrochemicals and midstream and upstream oil and gas, with applications that include steam turbines, gas turbines, compressors, distillation, pipeline systems and liquefaction facilities. Because the relay is selected for stroking speed rather than for the process fluid, it is specified wherever a large actuator volume would otherwise make the valve too slow, for example on the compressor and pipeline systems that Baker Hughes names among its applications. In Oman, typical sites include gas compression and processing plants and refinery units in Sohar and Duqm.

In Oman and the GCC, Seven Star LLC supplies the Masoneilan BR400 with the actuators it serves, such as Masoneilan Type 51/52/53 piston actuators and Masoneilan Type 87/88 spring-diaphragm actuators. For smaller actuators, the Masoneilan BR200 booster relay is usually sufficient. Our engineers compare actuator volume, required stroking time and supply pressure to recommend the correct model rather than leaving selection to trial and error.

Technical Specifications

The table summarises the published data for the Masoneilan BR400 from the Baker Hughes BR200/BR400 datasheet. BR200 values are shown only where they clarify the difference between the two models.

Related Masoneilan positioners and accessories include the Masoneilan 4411 I/P transducer, Masoneilan 4700P/4800P pneumatic positioner, Masoneilan 78 air filter regulator and Masoneilan SVi1000 digital valve positioner.

Request a Quote for Masoneilan BR400

To request pricing or technical support for the Masoneilan BR400, send a formal RFQ to the Seven Star LLC instrumentation division stating the actuator type and volume, supply pressure, ambient temperature range and whether a stainless steel body is required. We can advise on availability and lead time, confirm the correct booster size and provide the Baker Hughes datasheet from this page. In Oman and the GCC, Seven Star LLC delivers genuine products with manufacturer documentation and local engineering support.