Masoneilan 28000 EB Cryogenic Extended Body Varipak Microflow Control Valve

Overview

The Masoneilan 28000 EB is the cryogenic extended-body version of the Baker Hughes Varipak microflow control valve. The EB suffix in the Varipak numbering system denotes the cryogenic construction, and the technical specification lists it as the 28000 EB Series. It is built for processes that require thermal insulation, such as liquid nitrogen, oxygen, argon and LNG-related systems, where the valve body sits in a cold box at cryogenic temperature while the actuator and packing stay in the warm zone outside.

In Oman and the GCC, Seven Star LLC proudly supplies the Masoneilan 28000 EB to industrial gas, LNG and process customers across the Sultanate of Oman and the GCC. Our valve team in Muscat checks the minimum temperature, mounting angle and cold-box arrangement with you before an RFQ is raised, because cryogenic valves are not simply standard valves with a longer neck.

How the Masoneilan 28000 EB Extended Body Works

The principle of the Masoneilan 28000 EB is separation of the cold and warm zones. An insulating interface sits between the valve body, which is the cold zone, and the body extension, which reaches into the higher temperature warm zone. The valve body and its thermal extension are installed inside the cold box, and the plug can be removed and inspected through the extension without disturbing the valve body. Baker Hughes states that this eliminates complicated preliminary dismounting and prevents any interference with the cold box, which is the main maintenance advantage of the design.

Three details keep heat out and cryogen in. The bonnet is located away from the cryogenic fluid, so the body gasket is not inside the cold zone and a leak of the cryogen into the insulated space is prevented. Thin-walled metal tubes form the body extension and coupling sleeve to reduce heat inflow by conduction, and the annular space is kept small to exclude convection currents. Finally, the plug is designed so that its working parts are accurately centred in relation to the seat and the guiding runs in a uniform temperature zone, which avoids sticking as the metal contracts.

Engineering Design of the Masoneilan 28000 EB

The body and extension of the Masoneilan 28000 EB are made from ASTM A182 grade F316L, and for cast bodies up to Class 600 the technical specification lists ASTM A351 grade CF3M, a material that keeps its ductility at low temperature. A plug extension stem and a pin are added for the cryogenic extended body, and the seat gasket listed on the EB construction page is an O-ring in PTFE, whereas the standard materials table lists a Grafoil gasket bonded to 316 stainless steel for the seat ring (trims 1 to 9), so the gasket for a given order is confirmed from the order data. For trims 1 to 5 the seat is ASTM A564 grade 630 condition H900, which is 17-4 PH stainless steel, while the trim 0 parts use the standard material. The rated Cv range is 3.8 down to 0.10, covering trim numbers 0 to 5.

The rated range on the EB construction page is -320°F to +300°F (-196°C to +150°C), and that is the range quoted here. The general temperature table of the same document gives a wider -321°F to +650°F for the cryogenic extended type (and -148°F to +650°F for gaseous hydrogen service), so any duty above +300°F is referred to Baker Hughes before an order is placed. The body rating is ASME Class 150 to 600 (ISO PN 20 to 100), except that trim 0 is limited to ASME Class 150 to 300 (ISO PN 20 to 50). Seat leakage is Class IV. The body can be mounted to suit the piping as long as the angle between the valve axis and the vertical does not exceed 60 degrees.

Key Features

The following points summarise the benefits of the Masoneilan 28000 EB:

• Insulating interface between the cold-zone body and the warm-zone extension protects the actuator and packing.
• The plug of the Masoneilan 28000 EB can be removed and inspected without disturbing the body inside the cold box.
• The bonnet and body gasket sit outside the cold zone, so cryogen cannot leak into the insulated zone.
• Thin-walled extension tubes and a reduced annular space limit conduction and convection heat inflow.
• Body and extension of the Masoneilan 28000 EB in ASTM A182 grade F316L stainless steel for ductility at -320°F.
• Rated Cv from 3.8 to 0.10 for trim numbers 0 to 5, with 17-4 PH seat on trims 1 to 5.
• The Masoneilan 28000 EB is rated ASME Class 150 to 600 (ISO PN 20 to 100) with Class IV seat leakage.
• Mounting up to 60 degrees from the vertical to suit the cold-box piping.

Industrial Applications

The Masoneilan 28000 EB suits low-flow control in cold boxes: nitrogen and oxygen purification, argon recovery, helium and liquid natural gas systems, and cryogenic sampling or let-down lines. In Oman the relevant duties are LNG facilities and their utilities, industrial gas production serving the Sohar and Salalah economic zones and the cryogenic equipment used in air separation, where a long-neck valve with an accessible plug saves a cold-box shutdown.

Seven Star LLC, the trusted supplier for Masoneilan, distributes the Masoneilan 28000 EB to EPC contractors and operators throughout Oman and the GCC. Customers who need only a standard-temperature valve should look at the Masoneilan 28000 Series Varipak valve; the 28000 Varipak seal and O-ring kit supports every Varipak construction, and the Masoneilan SVI3 digital valve positioner belongs to the digital positioner family named for the warm-zone actuator.

Technical Specifications

The table sets out the cryogenic data that the Baker Hughes Varipak technical specification (Rev. C, 12/2025) publishes for the Masoneilan 28000 EB. Complete data and materials are in the official document.

Related Masoneilan valves with cryogenic construction include the Masoneilan 21000 Series globe valve with cryogenic bonnet and Masoneilan 36005 V-Max ball valve.

Request a Quote for Masoneilan 28000 EB

An RFQ for the Masoneilan 28000 EB should give the fluid, minimum temperature, flow rate, pressure and cold-box dimensions, so that the trim number and the extension length can be confirmed. Our Muscat instrumentation division checks availability and lead time and provides the technical specification and fact sheet for download from this page. Seven Star LLC is the trusted supplier for Masoneilan in Oman and the GCC, with manufacturer documentation and local support behind every valve.