Masoneilan 535V Series Microflow Pressure Regulator
Overview
The Masoneilan 535V Series is the microflow member of the Baker Hughes Masoneilan 500 Series regulators. It is built for very small flow rates that a conventional regulator cannot control well: Model 535V reduces downstream pressure of air, liquids, saturated steam and superheated steam, and Model 535V-50 maintains a differential pressure. The Masoneilan 535V Series uses a standard 28000 Series body with an integral bonnet in 1/2, 3/4 and 1 inch sizes (15, 20 and 25 mm), as listed in the body rating, flow coefficient, dimension and weight tables, and it is operated by the 10900 Series spring-diaphragm actuator. Ten different plug and seat ring assemblies provide rated Cv values from 0.004 to 3.8, a range that reaches well below the smallest trim in the larger 535H family.
In Oman and the GCC, Seven Star LLC proudly supplies the Masoneilan 535V Series to laboratories, packaged-skid builders and process plants in the Sultanate of Oman and across the GCC. We help engineers in Muscat convert a small-flow duty into the correct trim number and spring range, and provide genuine Masoneilan documentation and regional support with each regulator.
Operating Principle of the Masoneilan 535V Series
The Masoneilan 535V Series is a direct-operated regulator, so the controlled pressure itself moves the plug. The adjustable spring of the actuator is set to the desired pressure and holds the plug open; when the controlled pressure rises above the set point, it acts on the diaphragm and closes the plug, and variations in pressure produce the movement needed to restore the set point. The controlled pressure is piped from a convenient point 1.8 to 3 m (6 to 10 ft) from the regulator, or from the discharge line near the pump on pump applications, to the 1/2 inch NPT connection in the diaphragm case.
The 535V-50 differential version of the Masoneilan 535V Series holds one pressure above a reference pressure by an adjustable amount. Here the actuator spring holds the regulator open, and an increase in the differential above the set point closes it. The manual stresses that pressure must be raised on both sides of the diaphragm at the same time to avoid diaphragm failure, and recommends a needle valve and gauge in each control line, placed close enough together that both can be handled simultaneously. In the 535V these needle valves also act as adjustable chokes against cycling caused by pump pulsation.
Engineering Design of the Masoneilan 535V Series
The distinctive part of the Masoneilan 535V Series is its trim. Eight plugs and five seat rings combine into ten trims, numbered 0 to 9, with orifice diameters of 14.3, 9.55, 4.47, 1.63 and 2.03 mm. The four plugs for trims 6 to 9 differ only by the angle of the flat machined on the tip, sharing the same seat ring and spacer, which is how very fine Cv values are reached. For trims below Cv 0.10 the seat ring is a two-part assembly with a spacer. Travel is 2.54 mm (0.1 inch) on a 7.925 mm (5/16 inch) stem, the characteristic is linear and shutoff is metal seat Class IV. The finest trims use Stellite No. 6 seat rings and solid Stellite No. 12 plugs, which resist wear at very small orifices.
The body of the Masoneilan 535V Series is the standard 28000 Series design with an integral bonnet, except for the 102 mm flanged body. Ratings are ANSI Class 150, 300 and 600 flanged, NPT screwed and flangeless, with body materials of 316 steel and stainless steel. A packing quick-change method lets the whole actuator be removed without disturbing calibration on trims of Cv 0.6 to 3.8, although the manual advises against it for finer plugs. As on the other 500 Series regulators, hot services require the actuator to be mounted below the body centreline with a condensate barrier to protect the diaphragm.
Key Features
The following characteristics make the Masoneilan 535V Series the right choice for very small flows:
- Ten trims with rated Cv from 0.004 to 3.8 allow stable control of extremely small flows.
- The standard 28000 Series body gives compact, familiar dimensions and a range of end connections.
- A linear characteristic gives proportional flow change with plug travel.
- Direct-operated spring-diaphragm action needs no positioner, air supply or electrical power.
- The -50 differential version maintains one pressure above another by an adjustable amount.
- Flanged ANSI Class 150 to 600, screwed NPT and flangeless bodies cover most piping standards.
- Seat rings and plugs can be replaced in the field, and recommended spare parts are listed in the manual.
- The manual gives an estimated useful life of 25 years or more with annual inspection and routine maintenance.
Industrial Applications
The Masoneilan 535V Series belongs wherever a small amount of fluid must be held at a precise pressure: pilot and sample lines, analyser and laboratory supplies, chemical injection and dosing skids, small steam users and tracing, and purge or blanketing gas to instruments. In Oman such duties are common in oil and gas facilities, gas processing, pharmaceutical and food plants, desalination and power plants in Muscat, Sohar and Salalah, where the main process lines are large but the supporting lines are very small.
In Oman and the GCC, Seven Star LLC supplies the Masoneilan 535V Series with its related products, including the Masoneilan 28000 Series Varipak valve that shares its body design, the Masoneilan 28000 Series seal and O-ring kit and the Masoneilan 172 Series regulator for larger direct-operated duties. Our team can help decide between them.
Technical Specifications
The table below summarises the main data of the Masoneilan 535V Series from the Baker Hughes technical specification and manual. Dimensions, weights and actuator limits are in the official datasheet.
| Parameter | Specification |
|---|---|
| Model | Masoneilan 535V (pressure reducing, microflow) and 535V-50 (differential pressure) |
| Service | Air, steam, gas, liquids |
| Sizes | 1/2, 3/4 and 1 inch (15, 20, 25 mm) per the data tables; the foreword names only 3/4 and 1 inch |
| Body | Standard 28000 Series with integral bonnet, flow to open, single seat |
| Ratings and ends | ANSI Class 150, 300, 600 flanged; NPT screwed; flangeless |
| Body material | 316 steel, stainless steel |
| Trim | Ten trims (0 to 9); Stellite No. 6 seat ring and Stellite No. 12 plug on trims 6 to 9 |
| Rated Cv | 0.004 to 3.8 (3.8 on the 1 inch body only; 2.3 is the highest on 1/2 and 3/4 inch) |
| Characteristic | Linear |
| Travel and stem | 2.54 mm (0.1 inch); 7.925 mm (5/16 inch) |
| Seat leakage | Metal seat, Class IV |
| Actuator | 10900 Series spring-diaphragm |
Face-to-face dimension and body weight
| Body style | Face to face (mm) | Body sub-assembly weight (kg) |
|---|---|---|
| Flanged, ANSI Class 150, 300 and 600 RF | 160 | 7.5 to 9.5 |
| Threaded NPT | 102 | 5 |
| Flangeless | 102 | 5 |
Rated Cv by body size and trim number
| Trim number | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 inch (25 mm) | 3.8 | 2.3 | 1.2 | 0.6 | 0.25 | 0.1 | 0.05 | 0.025 | 0.01 | 0.004 |
| 1/2 and 3/4 inch (15, 20 mm) | – | 2.3 | 1.2 | 0.6 | 0.25 | 0.1 | 0.05 | 0.025 | 0.01 | 0.004 |
The foreword of the Baker Hughes specification names only the 3/4 and 1 inch bodies for the 535V, while the body rating, flow coefficient, dimension and weight tables all include the 1/2 inch size. Seven Star LLC follows the tables, so the Masoneilan 535V Series datasheet data above applies to 1/2, 3/4 and 1 inch bodies. For differential duty see the 535V-50 page, and for back pressure duty see the 536V page, which has its own instruction manual and actuator ranges.
Request a Quote for Masoneilan 535V Series
To request pricing or technical support for the Masoneilan 535V Series, send a formal RFQ to the Seven Star LLC instrumentation division with your fluid, set pressure, inlet pressure and required flow in Cv or flow units. We confirm trim and spring range, advise on regional warehouse availability and supply the Baker Hughes technical datasheet from this page. In Oman and the GCC, Seven Star LLC delivers genuine products with manufacturer documentation and local support.
Masoneilan, a Baker Hughes brand, is a global leader in the design and manufacture of control valves, pressure regulators, and valve automation systems. With over a century of engineering excellence, Masoneilan products are trusted for precise flow control, durability, and performance across critical industrial processes.
Its extensive product portfolio includes spring-loaded regulators, globe control valves, positioners, and digital valve controllers designed to optimize efficiency and ensure safe, stable operation in oil & gas, chemical, and power generation applications.
Seven Star LLC supplies authentic Masoneilan valves and regulators across the Middle East, providing clients with high-quality process control solutions backed by Baker Hughes’ global expertise and local support.
About Masoneilan: Company and Product Range
Masoneilan is a control valve brand in the Baker Hughes valves portfolio. According to Baker Hughes, it was founded by William Mason in 1882 and began with steam regulators; an automatic governor for steam pumps was patented in 1883. The brand is credited by its owner with the first eccentric rotary control valve and with developing the Cv method for calculating valve flow capacity.
The range covers globe control valves (21000, 28000, 41005 and 80000 series), rotary valves such as the 35002 Camflex and 31000 series, severe-service designs with Lo-dB noise-reducing trim, pressure regulators (171/172, 525/526 and 535H/536H series), actuators, SVI digital valve positioners and 12800 series pneumatic level instruments. Typical applications are in oil and gas, refining, chemical and power generation plants.
Browse Masoneilan products by category: Control Valves, Valve Actuator, Regulators, Valve Positioner, Level Transmitter.
Related products
Reviews
There are no reviews yet.