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Brand
Masoneilan
Masoneilan is a control valve brand of Baker Hughes with roots going back to 1882. Its Camflex eccentric plug rotary valve, 21000 series globe valve and SVI digital positioners are fixtures in refineries, gas plants and power stations. Every valve carries a serial number and a long model number that define the actuator, body and trim. Seven Star LLC is an independent supplier listing Masoneilan control valves, actuators, regulators, positioners and level instruments for buyers in Oman and the GCC. We source complete valves as well as Masoneilan spare parts against that nameplate data.
Read the full brand profile- 144 products
- 6 categories
Brand profile
About Masoneilan
- Founded
- 1882
- Speciality
- Control valves
- Listed with us
- 144 products in 6 categories
Masoneilan is a control valve brand of Baker Hughes with roots going back to 1882. Its Camflex eccentric plug rotary valve, 21000 series globe valve and SVI digital positioners are fixtures in refineries, gas plants and power stations. Every valve carries a serial number and a long model number that define the actuator, body and trim.
Seven Star LLC is an independent supplier listing Masoneilan control valves, actuators, regulators, positioners and level instruments for buyers in Oman and the GCC. We source complete valves as well as Masoneilan spare parts against that nameplate data.
Masoneilan at a glance
| Origin | Mason Regulator Company, Boston area, USA (1882). It acquired the Neilan Company of California in 1931, and the two names became Masoneilan. |
|---|---|
| Ownership | Dresser Industries from 1985, then GE Oil & Gas, now Baker Hughes |
| Milestones the company cites | Cv flow coefficient introduced (1944), spring-diaphragm actuators (1955), Camflex rotary globe valve (1968), Lo-dB low-noise trim (1975), LincolnLog axial-flow letdown valve (1982), Varipak (1984), V-Log (1998), SteamForm steam conditioning valve (2002) |
| Product families | Globe, rotary, butterfly and severe-service control valves, actuators, digital positioners, self-operated regulators and displacer level instruments |
| Typical duty | Throttling control of steam, gas, hydrocarbons and water, high-pressure letdown, anti-cavitation and low-noise service |
Masoneilan control valves and actuator series
| Series | Type | Typical use |
|---|---|---|
| 21000, 21009 | Top-guided and cage-guided globe valves | General process control. Cryogenic (21000 C), bellows seal (21000 BS) and API 6A versions are also made |
| 41005 | Cage-guided globe valve | Higher pressure drop and larger sizes, up to 30-36 inch extended sizes; VRT anti-cavitation and API 6A versions |
| 35002 Camflex II | Eccentric plug rotary control valve | Erosive, flashing and dirty service; HC high capacity, DVD low noise and GR globe replacement versions |
| 37002 MiniTork II, 39003/39005, 33000 | Butterfly control valves, high-performance and triple-offset | Large flows at low pressure drop, and tight-shutoff duty |
| 28000 Varipak | Microflow control valve | Very small flows, with adjustable Cv |
| 78400/18400 LincolnLog, 77000, 49000 V-Log | Severe-service multi-stage valves | High-pressure liquid letdown, anti-cavitation and gas noise reduction |
| 84000/84003 SteamForm, DSH | Steam conditioning valves and desuperheaters | Turbine bypass and steam pressure and temperature reduction |
| 87/88, 37/38, 51/52/53 | Spring-diaphragm and piston actuators | Linear and rotary valve actuation; diaphragms and soft-goods kits are listed separately |
| SVI3, SVI II AP, SVi1000, SVI FF | Digital valve positioners | HART or FOUNDATION Fieldbus positioning with valve diagnostics; the SVI II ESD adds partial stroke testing |
| 4700/4800, 8013 | Pneumatic and electro-pneumatic positioners | Older installed base. Many sites move to SVI positioners at overhaul |
| 525/526, 535/536, 171-174 | Self-operated pressure regulators | Pressure reducing and back-pressure control without external power |
| 12400, 12800 | Displacer level transmitters and controllers | Digital (12400, HART, SIL 2 version 12420) and pneumatic (12800) level control on separators and vessels |
Where Masoneilan valves are used
Throttling duty on steam, hydrocarbons, gas and water is the daily work of these valves. Typical services are feedwater and steam conditioning in power plants, separator and compressor loops in gas processing, high-pressure-drop letdown, cryogenic service in LNG and air separation, and general flow, pressure and level control in refineries and chemical plants.
Ordering Masoneilan valves and spare parts: what we need
For spare parts the serial number decides the order, because the factory record behind it lists the trim, materials and actuator. Send a clear nameplate photo with the serial number, model number, size and pressure class. For a new valve, add the process data: fluid, inlet and outlet pressure, temperature, minimum, normal and maximum flow, required leakage class, fail position, air supply and control signal. When an older positioner or valve series is no longer made, we quote the successor that Baker Hughes names and list the mounting kit it needs.
Facts checked against Baker Hughes Masoneilan product information and the company’s published timeline, October 2026.
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Smart Valve Positioner Guide: HART Diagnostics, Partial Stroke Testing, Calibration and Troubleshooting
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Looking for Masoneilan parts not listed here, or pricing for a project? Send us the part numbers and quantities. Seven Star LLC sources genuine Masoneilan products for customers across Oman and the GCC and replies with a formal quotation.
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Frequently Asked Questions
How do I read a Masoneilan model number?
The number on the nameplate is built in blocks. The leading digits describe the actuator type and its action, the digits that follow give the body series and the trim and design options. In 35002, for example, the body series is the Camflex II. Send the whole string with the serial number so the valve can be identified without guesswork.
What do you need to identify Masoneilan spare parts such as trim, packing or diaphragms?
The valve serial number from the nameplate is the starting point, because Masoneilan parts are selected from the original build record. Add the model number, valve size, pressure class and the part you need (plug, seat ring, cage, packing set, gasket set, diaphragm). If the nameplate is unreadable, send body markings and photos of the valve and actuator.
Can a Masoneilan SVI positioner be fitted to an older Masoneilan valve?
SVI digital positioners are mounted on both rotary and reciprocating Masoneilan actuators using a mounting kit specific to the actuator type and size. To check the fit we need the actuator model, stroke or rotation angle, the control signal and communication protocol required, and the hazardous area approval for the site. We confirm kit and positioner version from the manufacturer's documentation.
Which documents does the manufacturer issue with a Masoneilan control valve?
That depends on what is specified in the order. Material certificates for pressure-containing parts, hydrostatic and seat leakage test reports and the valve datasheet are the usual set, and positioners carry their own hazardous area certificates. Requirements such as NACE compliance or third-party witness testing must be stated in the inquiry, because they cannot be added after manufacture.
Is Seven Star LLC a distributor of Masoneilan valves?
No. Seven Star LLC is an independent supplier that sources Masoneilan valves, actuators, positioners and spare parts through commercial channels. We check the model number and serial data against the manufacturer's documentation, propose the manufacturer's successor when a series is obsolete, and provide the datasheet and the certificates the manufacturer issues with the order on request.