What is a threadolet?

What is a threadolet?

A threadolet is the same basic design as a “weldolet.” However the main difference is the fitting has a female threaded connection to mate to the branch connection. This makes a 90° branch and comes in full size or reducing for a straight piece of pipe. It typically is in the size range of 1/2″ to 2″ and is welded over a hole either drilled or burned in the pipe. 

You use a “weldolet” when you want to weld a steel pipe or pipe fitting directly to the branch fitting and a “threadolet” when you want to screw the connecting pipe or fitting (e.g. valve) to the branch connection.

I believe there is a ANSI standard for the dimensions and pressure rating of these type of fitting. 

Depending of the relative size of the olet and the main pipe run the affect can vary from no affect to causing the header to bow or warp due to the heating and cooling of the weld. A good run of thumb is to never use an olet that is larger that 1/2 the size of the main pipe run. Size in this case being the nominal size.

Threadolet Dimensions Charts

Thredolet – Reducing and Flat, ANSI Class 3000, FCS
Thredolet – Size to Size and Flat, ANSI Class 3000, FCS
Thredolet – Reducing, ANSI Class 6000, FCS

Thredolet – Reducing And Flat, ANSI Class 3000, Fcs

  • Class 3000 – For Use With Sch. 80 Pipe.
  • Dimensions And Tolerances In Accordance With ANSI/ASME B16.11 And MSS SP-97.
  • Specifications For Carbon Steel Forgings In Accordance With ASTM A105.
  • Threads In Accordance With ANSI/ASME B1.20.1.
  • This Is A Threaded Connection Used For Making 90 Degree Branching From The Main Run Of Pipe.
  • Flat Thredolets Are Used On Welding Caps, Elliptical Heads And Flat Surfaces.
  • Each Outlet Size Is Available To Fit Any Run Curvature.
  • Outlet Combinations Fit A Number Of Run Pipe Sizes, And Fittings Are Marked Accordingly.

20190210023534 77142 - What is a threadolet?

Outlet Size (NPS) A B C Approx. Weight (lb)
1/8 3/4 1 5/8 0.10
1/4 3/4 1 5/8 0.10
3/8 13/16 1 1/4 3/4 0.20
1/2 1 1 13/32 15/16 0.25
3/4 1 1/16 1 23/32 1 5/32 0.35
1 1 5/16 2 1 7/16 0.60
1 1/4 1 5/16 2 9/16 1 3/4 0.90
1 1/2 1 3/8 2 27/32 2 1.00
2 1 1/2 3 15/32 2 9/16 1.75
2 1/2 1 13/16 4 1/16 3 3.00
3 2 4 13/16 3 11/16 4.35
3 1/2 2 1/8 5 7/32 4 5.75
4 2 1/4 5 31/32 4 3/4 7.10
5 2 5/8 7 5/16 5 9/16 12.00
6 2 3/4 8 5/8 6 11/16 15.30

Thredolet – Size To Size And Flat, ANSI Class 3000, Fcs

20190210023753 93158 - What is a threadolet?

Outlet Size (NPS) A B C D Approx. Weight (lb)
1/2 1 1 3/8 15/16 5/8 0.15
3/4 1 1/16 1 5/8 1 3/16 13/16 0.25
1 1 5/16 2 1 7/16 1 1/16 0.45
1 1/4 1 5/16 2 3/8 1 3/4 1 3/8 0.70
1 1/2 1 3/8 2 7/8 2 1 5/8 0.90
2 1 1/2 3 1/2 2 9/16 2 1/16 1.40
2 1/2 1 29/32 4 1/16 3 2 1/2 2.50
3 2 4 13/16 3 11/16 3 1/16 4.30
3 1/2 2 1/8 5 3/8 4 7/16 3 9/16 4.50
4 2 1/4 6 1/16 4 3/4 4 1/16 6.80
5 2 7/16 7 1/4 5 1/4 5 1/4 9.20
6 2 3/4 8 11/16 5 3/4 5 3/4 15.70

Thredolet – Reducing, ANSI Class 6000, Fcs

  • Class 6000 – For Use With Sch. 160 Pipe.
  • Dimensions And Tolerances In Accordance With ANSI/ASME B16.11 And Mss Sp-97.
  • Specifications For Carbon Steel Forgings In Accordance With Astm A105.
  • Threads In Accordance With ANSI/ASME B1.20.1.
  • This Is A Threaded Connection Used For Making 90 Degree Branching From The Main Run Of Pipe.
  • Flat Thredolets Are Used On Welding Caps, Elliptical Heads And Flat Surfaces.
  • Each Outlet Size Is Available To Fit Any Run Curvature.
  • Outlet Combinations Fit A Number Of Run Pipe Sizes, And Fittings Are Marked Accordingly.

20190210023753 93158 - What is a threadolet?

Outlet Size (NPS) A B C Approx. Weight (lb)
1/4 1 1/8 1 11/32 9/16 0.30
3/8 1 1/8 1 11/32 9/16 0.30
1/2 1 1/4 1 23/32 3/4 0.45
3/4 1 7/16 1 61/64 1 0.75
1 1 9/16 2 7/16 1 5/16 1.25
1 1/4 1 5/8 2 23/32 1 1/2 1.60
1 1/2 1 11/16 3 1/4 1 15/16 1.95
2 2 1/6 4 1/32 2 3/4 5.00

How to order a threadolet?

Specify Size

  • Outlet size
  • Run or Header

Indicate Class or Schedule/Pipe Wall

  • Class 3000 or 6000 – Threaded or Socket
  • STD, XS, Sch 160/XXS, ect. – Buttweld

Select Material

  • Carbon steel
  • Stainless steel
  • Other

Specify Design Code (if available)

Weldolet VS Threadolet

A “weldolet” when you want to weld a pipe or fitting directly to the branch fitting and a “threadolet” when you want to screw the connecting pipe or fitting (e.g. valve) to the branch connection.
Source: China Threadolet Manufacturer – Yaang Pipe Industry Co., Limited (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

If you want to have more information about the article or you want to share your opinion with us, contact us at sales@steeljrv.com

Please notice that you might be interested in the other technical articles we’ve published:

References:

  • https://www.yaang.com
  • http://www.piping-designer.com/index.php/disciplines/mechanical/stationary-equipment/pipe-fittings/1608-branch-connection-fitting

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