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Tubing Head Adapters

tubing head adapter (n.) - Equipment used to adapt the uppermost connection of the tubing head to the lowermost section of the tree.

Providing a transition from the wellhead to the tree, the tubing head adapter is used for both single and multiple completions. FMC’s standard tubing head adapter product line consists of nine models, each designed to work with a set group of tubing heads and hangers. With threaded, flanged, or studded-top connections, most adapters can be machined with a hydraulic supply inlet for downhole control lines.


A-4 & A-4-M
A simple transition piece between the wellhead and the tree, the adapter hangs no load nor provide a controlled seal bore. The smooth seal bore on a tubing head is used when tubing is suspended from the tubing hanger. For low-pressure completions, these tubing hangers are not designed for tubing string manipulation or control lines.

The A-4-M uses a metal seal, whereas the A-4 uses elastomer sealing technology; and is used with the TC-1A-EMS hanger. The A-4 adapter can be used with virtually any tubing hanger configuration. 

B-2/P, B-1, & A-4-D
Considered "seal bore adapters" these products have the inside diameter (ID) machined to provide a controlled seal bore for an "extended-neck" tubing hanger or seal nipple. Capable of possessing a test port and/or a hydraulic supply inlet for control lines, seal bore adapters are more commonly used in advanced applications.

The B-2/P adapter fits with the TC-1A tubing hanger family, whereas the B-1 can be used with or with out a coupling. The A-4-D is intended for use with a dual completion, most often using the wedge tubing head, the TC-WD-ET.

BO-2 & BO-10
Known as the coupling-type adapters, the BO-2 and BO-10 provide a means to suspend the tubing in conjunction with a special coupling. Creating a lower connection for the tubing head and an upper connection for the tree, the coupling also accepts a BPV.

High-pressure completions requiring tubing manipulation through a wrap-around packoff, needing a BPV, or an inlet for control lines, work well with a coupling adapter. With an ACME thread machined into the adapter’s bottom ID to be utilized in conjunction with the coupling, the adapter can be installed. In addition, when a tree is trimmed for critical service (H2S, chlorides), using the coupling adapter with a coupling nut prevents galling of threads between the adapter and coupling on makeup, a feature provided by FMC.

The BO-2 is installed as an entire assembly by rotating it onto the coupling, and is used as a studded top connection only. The BO-10 installs without the rotation of the tree, and is also solely a studded top connection.

A-3-EC & A-5-EC
The Electro-submersible Pump (ESP) adapters, designed with seal bores, accommodate both a tubing hanger neck seal and an electrical power feed-through device. Standard ESP adapters are equipped with rotating flanges to makeup to the tubing head, to minimize alignment concerns. By nearly eliminating the concern for proper alignment, the ESP hanger and tubing head flange are much simpler to install. The ESP product family is available for 3,000 – 5,000 psi applications.