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Casing And Tubing Coupling

Product:Casing and Tubing Coupling, Casing Coupling, Tubing Coupling Application:Used for connect 2 joints of tubing or casing Size:Tubing Coupling : 1.9'' - 4-1/2'' Casing Couping : 4-1/2'' - 13-3/8'' Pipe Standard: API 5CT and 5B PSL1/PSL2 J55,K55,N80-1,N80-Q,API 5CT and 5B L80-1,C90, C95,T95, P110, Q125 Surface:Whole Phosphating or inside phosphating and outside coating Thread:NUE, EUE, STC, LTC, BTC etc



About Tubing coupling

Normally tubing coupling OD maximum is 4 1/2”, as the tubing pipe is applied for the drilling activities (Inside the tubing is the sucker rod to drill/pump the oil), couplings type is more various and rigorous than casing, mostly used is thicken type upset coupling (Internal upset and external upset), for short is EUE coupling, it is the most favorable in tubing connections. Tubing with EU end (EUE) coupling connection also called UPTBG. Because of the end of the tubing is thickened (upset), the connecting stress is better than buttress coupling.

Buttress coupling another type used for tubing connections, it has the same thickness of the pipe body, called NU end (NUE)tubing or TBG.


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.

About Casing coupling

Casing coupling is for the dimensions more than 4 1/2 inch. Differently than tubing coupling is, casing coupling normally does not need to be thickened (Non-upset), which means no upset casing coupling, so it has following types:

• BTC: Buttress coupling

• LTC: Long buttress coupling

• STC: Short buttress coupling

All three types has same thickness of the casing pipe body, just have different lengths.

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.

Seamless and ERW Casing




K55, N80, L80, C95, P110, Chrome, J55(Modified), J55 (API), PS80

Special Grades

For sour services and for deep well with high collapse properties


OD 4" - 26" WT - 0.2 -0.5"

Length range

1, 2 or 3

Thread connections

API (STC and LTC), BTC, extreme line, etc.

Seamless and ERW Tubing




J55 (API) J55(Modified), N80, L80, L80 13Cr, P110, Q125, H40 (API)

Thread connections

API 5B - Last Edition or Premium, EUE, NUE, special seal, metal-to-metal seal and VAGT


Casing Couplings Short Thread Specifications:

Casing Couplings
Short Thread

Casing Size OD (inches)

Coupling Size OD (inches)

Length (inches)

Weight per Coupling (lbs)

Palletized Carton Quantity







Packing and shipping

 Now the main business scope of our company covers various kinds of Stainless steel and carbon steel materials , such as hot rolled / cold rolled stainless steel coils / sheet , Seamless / welded stainless steel pipe ( tube ).






Warehouse Storage

As a steel supplier in Shandong Province, Zhongyilian Steel (Shandong) Co., Ltd. has its own factory.


Customer conversation

We have advanced technology and equipment, and we have a highly qualified management team with energy and service consciousness. So far, we have more than 1000 regular customers and we have ISO,CE certification.


Application field

We promise to provide the right products at the right time. The products are exported to Southeast Asia, the Middle East, North America, South America, Europe, Africa, Australia and other regions, forming a global marketing network.




Q: Do you accept the third party inspection?

A: Yes absolutely we accept.

Q: Do you provide the samples? Free or Extra?

A: The cost of the samples is according to the value.The cost of the freight is necessary.

Q: About the complaint,quality problem,etc after-sales service,how do you handle it?

A: We will have certain colleague to follow our order accordingly for each order with professional after-sales service. If any claim happen, we will take our responsibility and compensate as per contract. For better serve our client, we'll keep tracing feedback of our products from clients and that's what make us different from other suppliers. We're customer care enterprise and our mission is to add honor to Made in China.

Q: How can you ensure the quality of your product?

A: All products have to go through three checks in the whole manufacturing process,it includes production and Random Testing in warehouse and Before Shipping.

Q: What is your delivery time and the supply ability?

A:The delivery time normally within 15~28working days,we can supply about 10,000tons every month.

Q: Do you have large amount of steel products in stock?

A: Yes , we have a large-scale indoor warehouse with perennial spot stocks totally above 5000 tons.

Q: How to order?

A: Buyer sends the enquery --> Buyer gets the quotation --> Order confirmation --> Buyer send the deposit --> Seller prepares goods --> Seller makes the strict inspection --> Buyer Arranges Balance Payment --> packing and delivery

Q: Can I get your best price?

A: Price is different based on steel grade, size and quantity. Our goal is to provide you the best price with great quality assured in a long run. Please leave your contact information for the best quotations, we will get back to you with the best solutions as soon as we can. Please give those info. for price checking. If the required is sheet metal fabrication, please send drawing.