Brand: Masoneilan

Masoneilan 31000 Series Rotary Control Valve Seal Kit

Name: Masoneilan 31000 Series Seal Kit – Manual & Price Quote
Brand: Masoneilan

Description

Overview

The Masoneilan 31000 Series is Baker Hughes’ PFA-lined eccentric rotary control valve, engineered specifically for highly corrosive chemical service where a conventional metal-wetted valve would be attacked by the process fluid itself. A cast iron body carries a perfluoroalkoxy (PFA) lining anchored by dovetail grooves for mechanical adhesion, so the corrosive fluid never contacts bare metal, but that same corrosion-resistant design places the entire sealing burden on a small set of non-metallic soft goods – PTFE/graphite chevron packing backed by a double O-ring follower – because a metal gasket or standard elastomer would fail in the same aggressive chemical environment the PFA lining is there to resist. Baker Hughes engineers each Masoneilan 31000 Series seal kit against the confirmed size and lining condition of the installed valve rather than a single stocked part number.

With fast quotation turnaround and technical support, Seven Star LLC proudly supplies this Masoneilan 31000 Series rotary control valve seal kit to chemical processing, water treatment, and corrosive-service facilities across Oman and the wider GCC. Seven Star LLC’s instrumentation division confirms the valve size and packing configuration against the customer’s nameplate before every order, ensuring the chevron packing and double O-ring follower hardware arrive matched to the actual installed valve and its process chemistry.

Operating Principle

The Masoneilan 31000 Series throttles corrosive fluid through an eccentric rotary plug riding inside the PFA-lined body, delivering the throttling accuracy, low dynamic forces, and tight shutoff typical of Masoneilan’s eccentric-plug rotary family while keeping the flow path entirely lined against chemical attack. Because the PFA lining cannot be relied upon to seal around a rotating stem the way it seals the flow path itself, Baker Hughes specifies PTFE/graphite packing in a chevron-ring configuration, chosen because chevron geometry maintains sealing contact across a wider range of compression than flat packing rings, which matters on a rotary stem that sees continuous partial-rotation cycling rather than the linear stroke of a globe valve.

Backing up the chevron packing is a double O-ring follower, a design specifically selected for corrosive service so that a single O-ring reaching the end of its chemical-resistance life does not immediately become the sole barrier to atmosphere; the second O-ring provides a functioning backup while the first is inspected or replaced, and both are renewed together at every rebuild rather than staggered, since PTFE/graphite packing and the O-ring compound age together under the same chemical exposure. Rebuilding a Masoneilan 31000 Series valve with a correctly matched chevron packing and O-ring set restores the stem seal without disturbing the PFA lining itself, which is engineered to outlast the soft-good seal components by a wide margin under normal corrosive-service conditions.

Engineering Design of the Masoneilan 31000 Series

The Masoneilan 31000 Series is built in compact sizes from 1 to 3 inches (25 to 80 mm) port diameter, rated to ANSI 150 and UNI-DIN 10–16 flange standards, and paired with a Model 35 spring-opposed rolling-diaphragm actuator that keeps the overall package lightweight and simple to maintain in the field. The linear flow characteristic and PFA-lined cast iron body are specifically suited to vacuum and high-temperature corrosive service, where the dovetail-grooved lining provides a guaranteed minimum wall thickness that resists chemical attack far longer than unlined valve of similar size.

Seven Star LLC packages the 31000 Series seal kit to the customer’s confirmed size and packing configuration, supplying the PTFE/graphite chevron packing rings and the double O-ring follower hardware as one traceable, chemically-compatible set, so plant technicians can complete a full stem-seal rebuild without introducing an elastomer or packing compound that is incompatible with the specific process chemical in service.

Key Features

This Masoneilan 31000 Series kit is engineered to restore full containment on an in-service PFA-lined rotary control valve. Key features include:

PTFE/graphite chevron packing rings sized to the confirmed port diameter of the customer’s Masoneilan 31000 Series valve.
Double O-ring follower hardware supplied as a matched pair for reliable backup sealing in corrosive service.
Chemically compatible packing and O-ring compounds selected against the customer’s confirmed process fluid.
Designed to be installed without disturbing the PFA lining’s mechanical anchoring to the cast iron body.
Compatible with the Model 35 spring-opposed rolling-diaphragm actuator interface used on this platform.
Covers the full 1–3 inch (25–80 mm) port diameter range across ANSI 150 and UNI-DIN 10–16 ratings.
Kit contents cross-checked against the current Baker Hughes 31000 Series documentation before dispatch.
Supplied with reassembly guidance covering chevron ring orientation and follower compression sequence.

Industrial Applications

The Masoneilan 31000 Series is specified across Middle East chemical processing, water and wastewater treatment, and corrosive-service utility systems wherever a PFA-lined flow path is required to resist chemical attack that would degrade an unlined valve within a short service life. Facilities around Muscat, Sohar, and the Salalah free zone that operate chemical dosing, effluent treatment, or corrosive process lines schedule Masoneilan 31000 Series chevron packing and O-ring rebuilds into planned maintenance, since the lightweight lined body and rolling-diaphragm actuator make this platform easy to service in place without a full valve removal.

With engineering support in Muscat, Seven Star LLC supplies this Masoneilan 31000 Series seal kit to reliability and instrumentation teams across the Sultanate of Oman and the broader GCC, supporting chemical processing and water treatment facilities that rely on this platform’s PFA-lined construction for corrosive fluid handling. Seven Star LLC’s manufacturer-verified sourcing ensures the packing and O-ring compounds supplied are chemically compatible with the confirmed process service.

Technical Specifications

Representative build data for the Masoneilan 31000 Series platform this kit is engineered to match:

Parameter	Specification
Model	Masoneilan 31000 Series
Valve Type	PFA-lined eccentric rotary control valve
Sizes Covered	1–3 inch (25–80 mm) port diameter
Pressure/Flange Ratings	ANSI 150; UNI-DIN 10–16
Packing Type	PTFE/graphite chevron rings
Backup Sealing	Double O-ring follower
Body Construction	Cast iron with dovetail-grooved PFA lining
Actuator	Model 35 spring-opposed rolling diaphragm
Flow Characteristic	Linear

Request a Quote for Masoneilan 31000 Series Rotary Control Valve Seal Kit

Seven Star LLC invites facility engineers, procurement leads, and maintenance planners across Oman and the GCC to submit a formal RFQ for the Masoneilan 31000 Series rotary control valve seal kit with the valve’s confirmed size and process fluid, so the correct chevron packing and O-ring compound are engineered without guesswork. Seven Star LLC supplies common 31000 Series soft-good variants on request, can furnish the current Baker Hughes technical datasheet on request, and can connect customers with its instrumentation division for turnaround planning.

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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

Is there one fixed part number for the 31000 Series seal kit?

No. The packing and O-ring compound are engineered against the confirmed size and process chemistry, so Seven Star LLC verifies nameplate data and service fluid before quoting.

Why does the 31000 Series use chevron packing instead of standard flat rings?

Chevron-ring geometry maintains sealing contact across a wider range of compression, which suits the continuous partial-rotation cycling of a rotary stem better than flat packing rings.

Why is a double O-ring follower used on this valve?

The double O-ring follower provides a functioning backup seal in corrosive service, so a single O-ring reaching the end of its chemical-resistance life does not immediately become the sole barrier to atmosphere.

Does the seal kit affect the PFA lining?

No. The kit renews the chevron packing and O-ring follower only; the dovetail-grooved PFA lining is engineered to outlast these soft-good components under normal corrosive-service conditions.

Is Seven Star LLC an experienced supply partner for Masoneilan products?

Yes. Seven Star LLC is an experienced supplier of Masoneilan in Oman and the GCC, supplying genuine seal kits, spares, and valves with part-number traceability.

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