Product Specification Level PSL-2 or PSL-3 API coupling specification As we told, one of the important figure of API coupling, that it shall be made of seamless, another is the same grade as the casing or tubing pipe body, and these materials are used for manufacturing the blank coupling.
Coupling should be processed from coupling blanks or from coupling stock, including manufactured in hot forging. Except Grade C and Q couplings shall not be in hot forging.
These two grades material are typically different from other grades, so if you are purchasing couplings in this grades, should pay more attention to read regulations in API 5CT spec. Coupling Mechanical Properties Mechanical properties of casing or tubing coupling shall comply to the clauses 7 and 10, covers test frequency, retest provision, etc. And this test records could be shown to third party inspector assigned from the client. How many types for the API couplings There are several types covered in API 5CT standard for coupling specifications, classified in regular couplings, special clearance couplings, combination couplings, reducing couplings, seal ring couplings, and special bevel tubing regular couplings.
Coupling bearing contact face inside and outside edges shall be rounded or broken, but shall not significantly reduce the width of the bearing face dimension b , since less thickness will not be safe to support the pipe weight.
The ends of couplings shall be faced exactly at right angles to the axis. Special clearance couplings In case specified in the contract, special-clearance reduced outside diameter Wc couplings for buttress BTC connection casing and external upset EUE connection tubing shall be furnished.
Unless otherwise specified, special-clearance external upset tubing couplings shall have a special bevel on both ends. The inside and outside edges of the bearing face shall be rounded or beveled.
The ends or root face when beveled of couplings shall be faced at right angles to the axis. Special-clearance coupling dimensions and tolerances shall comply to as given in Tables C. Color identification see clause Combination couplings Combination couplings with different types of thread of the same specified size shall be furnished when specified on the contract.
The minimum length and minimum OD of this coupling shall be sufficient to work with the specified size specified threads. Reducing couplings Reducing coupling is also kind of pup joint, used to connect two pipes of different diameter with the same or different types of thread on the two ends.
Same with combination coupling, minimum length and minimum diameter of reducing couplings shall be sufficient to support the specified size and threads. Seal-ring couplings Sealing-ring couplings conforming to the requirements shall be furnished when specified in the PO.
Grooves and threads shall be free of fins, wickers and ribbons that are loose or can become loose and fold into the thread dorm. Couplings shall be inspected after final machining of the groove. Special clearance coupling When specified in the order, special-clearance reduced outside diameter couplings for buttress casing and external upset tubing shall be furnished.
Combination coupling Reducing coupling are used to connect two pipes of different diameter with the same or different types of thread on the two ends, and shall be furnished when specified on the agreements. The minimum length and minimum diameter of reducing couplings shall be sufficient to accommodate the specified size and type of threads. Differences between Casing coupling and tubing coupling There are couplings for casing and couplings for tubing, the function is the same that to connect the pipe each other.
On the other hand, still there are some differences between the two. Because of the end of the tubing is thickened upset , the connecting stress is better than buttress coupling. Features The oil tubing coupling can solve the problem of fatigue fracture in the existing coupling due to stress concentration.
Oil tubing end is connected to the inside wall of the coupling in a tapered thread. The coupling body end and oil tubing are connected with same thread pitch flat thread. The coupling is not easy to produce fatigue fracture, and has good connection effect. It can prevent the accident of oil well pipe string break effectively. The oil casing coupling is a necessary piece used to connect the two casing.
The coupling manufacturing method is the same as seamless pipe. The steel pipe ends with internal thread to connect with the upper and lower casing. In order to ensure the joint tightness, the precision of screw thread is strictly required. Couplings shall not be expanded to provide required threads taper under API specifications. NOTE Couplings with API threads may not have a leak resistance as high as the internal yield pressure of the pipe body, due to inadequate bearing pressure between the coupling and pin.
Threading and Gauging API 5B covers dimensions, tolerances, and marking for API threads and the gauges that control the acceptance criteria for the threads. It includes thread element gauges, instruments, and requirements for the inspection of threads for line pipe, casing and tubing round threads , and buttress casing connections. Thread dimensions shown without specifications or shown as NA are not subject to inspection of diameter, ovality, and addendum.
Thread dimensions shown without tolerances are related to the basis for connection design and are not subject to measurement to determine acceptance of product. Coverage—Inspection Thread inspection is taken at the point of production before shipment, including inspection at some point of intermediate, at destination, or by third party inspection company from buyer or the manufacturer.
The manufacturer also has right to use other instruments or methods to control manufacturing operations; But material shall be accepted or rejected in case the inspection result complied to the standard or not. Thread inspection is performed using instruments designed to measure either the functional relationship of multiple thread elements or measure an individual thread element.
The inspection requirements include measurements of standoff, diameter, ovality, addendum, taper, lead, height, and thread angel. Ring and plug gauges are designed to measure the functional size of an internal or external thread.
Individual thread elements listed in API 5B are measured with one or more specific instruments. Premium coupling and threads type Premium connection is a higher class connection type for used to connect casing or tubing pipelines. Premium couplings and premium threads are the patent product that only with manufacturer authorization it can be produced or sold.
Below are common brands or models for the premium connections. For Group 4: Not only internal machining could be done to Coupling, external machining also could be done to.
Except API couplings and threads shall comply to C. Appearance quality According to API 5CT specification, the internal and external surface of coupling shall not have folding, cracks, separation, scaling and other defects. Test methods Tests for making couplings is similar with the casing and tubing, which includes: Tensile test, flattening test, hydrostatic pressure test, sulfide stress corrosion cracking test, grain size determination, transverse impact test and hardness test.
Octal supplies API couplings for casing and tubing connections, feel free to contact us for any of the request refer to the API or premium connections.
Tubings are screwed together through connections, which could either be: By means of integral joint the most common type of connection on small diameter pipe , Or by using a coupling the most common connection ; a collar with internal threads used to join two sections of threaded pipe.
Selection of tubing connections: The type of tubing connections selected for a completion will depend mainly on the well characteristics. The connection must be able to contain the produced fluids safely and at the maximum pressures anticipated. The basic requirements of a tubing string connection are: Strength compatible with the operational requirements of the string during, and after running; Sealing properties suitable for the fluid and pressures expected; Ease of stabbing during make-up, and safe breakout when pulling the tubing; Resistance to damage, corrosion, and erosion.
API threads have a taper of 6. They are triangular and rounded on top. The seal is made by grease trapped between the threads, which is sufficient for low-pressure oil wells. API connections are perfectly well adapted and sufficient for most oil wells. Premium connections: Premium connections are proprietary connections that offer premium features not available on API connections. Most offer a metal-to-metal seal e.
VAM joint and Hydril joint for improved high pressure seal integrity. Premium connections exist with features such as flush connections, recess free bores, and special clearance. This type of connection is preferred for gas wells, high-pressure wells, as well as for wells producing corrosive effluents.
An example of a premium thread is shown in the following Figure. References: Well Completion and Servicing, D. Perrin Editions Technip.
Postman: Disqus API Case Study (1) – List Discussions and Get Thread Details
API Coupling and Threads for Casing and Tubing
With the Postman, you can quickly test the API endpoints and your parameters and then generate the codes for your prototype app. This article contains two beginner-level exercises. The first one is to get the discussion threads of a specific Disqus forum. The second one is to try querying the thread details by a thread ID, an identifier, or a source URL, respectively.
3 LP API thread gauge-3″ Line Pipe Ring Plug Gage
Click on the Register new application button. In the registration form, fill in the name and description of your application as well as your organization and website. After that, you can find the API key for your registered application in its Details page.
When in doubt, send a sample to the manufacturer to be sure.
API Thread Chart
The first step is to determine the threads per inch red column. Threads per inch is an important characteristic when trying to identify rotary shouldered connections. The photo shows 5 threads per inch. I like using the female or box threads to take my measurements. Here we measure the Counterbore — yellow column. Please note the following: 1 This is a tapered area and you want to take your reading as close to the box face as possible.
There might also be a bevel. The threads are listed by size. See the Qt Concurrent module documentation for details on the individual functions. Each WorkerScript instance can have one.
Tubing connection basics
When WorkerScript. When the script finishes running, it can send a reply back to the GUI thread which will invoke the WorkerScript. Using a WorkerScript is similar to using a worker QObject that has been moved to another thread. Data is transferred between threads via signals. See the WorkerScript documentation for details on how to implement the script, and for a list of data types that can be passed between threads.
Choosing an Appropriate Approach As demonstrated above, Qt provides different solutions for developing threaded applications. The right solution for a given application depends on the purpose of the new thread and the thread's lifetime. Below is a comparison of Qt's threading technologies, followed by recommended solutions for some example use cases.