Brand: Masoneilan

Masoneilan™ Type 87/88 Pneumatic Spring-Diaphragm Actuators

Name: Masoneilan 87/88 Pneumatic Spring-Diaphragm Actuators
Brand: Masoneilan

Description

The Masoneilan Type 87/88 Pneumatic Spring-Diaphragm Actuators are highly reliable and versatile actuators engineered for a wide range of globe control valve applications in industrial environments. Designed with precision and durability in mind, these actuators deliver consistent mechanical spring fail-safe operation, ensuring optimal performance and safety in demanding process control conditions.

One of the main advantages of the Masoneilan Type 87/88 Pneumatic Spring-Diaphragm Actuators is their adaptability across different pressure drop scenarios, from low to high, making them a preferred choice for industries such as power generation, refining, petrochemicals, and oil & gas operations. With the ability to incorporate manual override for precise mechanical valve positioning, operators can maintain control and efficiency even during critical system adjustments.

These actuators are built to perform in challenging industrial applications. In power generation, they are commonly found in steam turbine generators, condenser systems, cooling towers, turbine buildings, and reactor facilities. In refining and petrochemical sectors, they are essential for processes such as distillation, hydroprocessing, reforming, cracking, blending, and quenching. Their robust design allows them to handle the demanding conditions of midstream and upstream oil & gas operations, including pipeline integrity management, dehydration, liquefaction, and regasification.

The Masoneilan Type 87/88 Pneumatic Spring-Diaphragm Actuators also offer outstanding flexibility in installation and integration with various control valve systems. Their simple yet effective pneumatic spring-diaphragm mechanism ensures low maintenance requirements while delivering high reliability over long service periods. This reduces operational downtime and minimizes lifecycle costs, which is a key consideration for industrial operators.

In addition, the actuator’s ability to maintain performance under high temperature and pressure conditions makes it ideal for balance-of-plant operations, gas turbine control, and heat recovery steam generator applications. Whether in auxiliary systems, separation units, refrigeration processes, or liquefied natural gas (LNG) handling, these actuators deliver stable, precise control that meets stringent safety and efficiency standards.

With a proven track record of performance, ease of operation, and maintenance-free reliability, the Masoneilan Type 87/88 Pneumatic Spring-Diaphragm Actuators remain a trusted solution for process control in complex and demanding industries.

Technical Specifications

Parameter	Value
Manufacturer	Masoneilan (Baker Hughes)
Model	Type 87 / Type 88
Product Type	Pneumatic spring-diaphragm actuator for sliding-stem globe control valves
Sizes (Effective Diaphragm Area)	Size 6 (60 sq.in.), Size 10 (100 sq.in.), Size 16 (160 sq.in.), Size 23 and 23L (230 sq.in.)
Maximum Air Supply	60 psi (4.1 bar)
Stem Travel	0.8 in. (20 mm) to 4.0 in. (102 mm)
Action	Type 87 air-to-extend (direct-acting); Type 88 air-to-retract (reverse-acting)
Standard Materials	Carbon steel with zinc plating, cast iron and stainless steel; Buna-N/Polyester diaphragms; PTFE bushings

Technical Overview

The Masoneilan (Baker Hughes) Type 87 and Type 88 are pneumatic spring-diaphragm actuators used to operate Masoneilan sliding-stem globe control valves, providing simple, reliable fail-safe throttling actuation without requiring an electrical or hydraulic power source. Per Baker Hughes’ official technical specification (Doc BHMN-87-88-TS-19711B-0820), the actuator platform is offered in five effective diaphragm areas to match different valve sizes and thrust requirements: Size 6 (60 sq.in. / 387 sq.cm), Size 10 (100 sq.in. / 645 sq.cm), Size 16 (160 sq.in. / 1,032 sq.cm), Size 23 (230 sq.in. / 1,484 sq.cm), and a long-stroke Size 23L variant (also 230 sq.in. / 1,484 sq.cm effective area but with extended travel). Maximum air supply pressure across all listed sizes is 60 psi (4.1 bar). Stem travel ranges from 0.8 in. (20 mm) up to 4.0 in. (102 mm), with the longest travel available on the Size 23L.

The key functional difference between the two type designations is the fail-safe action: Type 87 is configured as "air-to-extend" (direct-acting), while Type 88 is configured as "air-to-retract" (reverse-acting). This allows the same actuator platform, differing only in spring and air-connection arrangement, to be specified as either fail-open or fail-closed depending on the process safety requirement of the specific control valve application — a critical decision point when specifying a control valve for a safety-critical process line. Exact thrust output at a given air pressure depends on the specific spring range selected for the application; Seven Star LLC recommends consulting the full Baker Hughes technical specification or our engineering team for the precise thrust-versus-pressure figures for a specific size/spring-range combination rather than relying on a single generic number, since Masoneilan publishes detailed thrust tables per size and spring range rather than a single figure per actuator size.

Standard-temperature units are constructed from carbon steel with zinc plating, cast iron, and stainless-steel components, with Buna-N/Polyester diaphragms and PTFE bushings as standard. Extended-temperature and ultra-low-temperature variants substitute silicone-rubber diaphragms and alternate alloys suited to their respective service temperature ranges, per the manufacturer’s materials table.

Applications

Type 87/88 spring-diaphragm actuators are used across process industries — oil and gas, refining, power generation, and chemical processing — to actuate Masoneilan sliding-stem control valves in general throttling service where a simple, robust, fail-safe pneumatic actuator is preferred over more complex piston or electric actuator types. Their broad range of diaphragm sizes and spring ranges allows them to be matched precisely to the thrust and travel requirements of a wide variety of valve sizes and process pressure conditions.

Why Seven Star LLC

Correctly specifying a Type 87 vs. Type 88 actuator — along with the right diaphragm size and spring range — is essential to achieving the intended fail-safe behavior of a control valve on a critical process line. Seven Star LLC works directly with customers across Oman and the GCC to confirm the correct actuator configuration for their specific valve and process safety requirement, sourcing genuine Masoneilan/Baker Hughes hardware with full documentation.

Request a Quote for Masoneilan™ Type 87/88 Pneumatic Spring-Diaphragm Actuators

Contact Seven Star LLC to request a quotation for the Masoneilan Type 87 or Type 88 pneumatic spring-diaphragm actuator. Our engineering team can help confirm the correct size, spring range, and fail-safe action (air-to-extend vs. air-to-retract) for your control valve application, and support reliable delivery across Oman and the wider GCC region.

Ordering Notes

When requesting a quotation, please specify the valve model and size the actuator will be mounted to, the required fail-safe action (fail-open or fail-closed), and the process service temperature, so Seven Star LLC can confirm the correct actuator size, spring range, and materials of construction for your application.

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About brand

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.

Browse Masoneilan products by category: Control Valves, Valve Actuator, Regulators, Valve Positioner, Level Transmitter.

Frequently Asked Questions

How does the Type 87/88 actuator achieve fail-safe operation?

It uses a mechanical spring-diaphragm design, so on loss of instrument air or control signal, the spring force drives the valve stem to its predetermined fail-safe position without relying on any electronic or stored-energy backup.

Can the valve be positioned manually during maintenance or an air-supply loss?

Yes, the Type 87/88 can be fitted with a manual override, allowing operators to position the valve mechanically for precise adjustment or emergency control when instrument air is unavailable.

What globe valve series does this actuator typically pair with?

It's the standard actuator for Masoneilan globe control valves such as the 10000 and 80000 Series, matched to the valve's stem thrust requirements across low to high pressure-drop applications.

What kind of process conditions is it built to handle?

It's designed for demanding, high-temperature and high-pressure duty in applications like steam turbine and heat recovery steam generator systems, distillation and hydroprocessing units, and LNG liquefaction/regasification trains.

What are the main maintenance advantages of a spring-diaphragm actuator versus a piston actuator?

The spring-diaphragm mechanism is mechanically simple with few moving parts, so it requires minimal routine maintenance while still delivering long-term reliable, repeatable positioning over extended service periods.

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