Malleable Iron 291 Plain Plug NPT Thread

Size: 1/4”-6”
aterial: ASTM A197/A197M
Dimension: ASME B16.3, B16.14
Union Dimension:B16.39
Thread: ASME B1.20.1
Pressure Rating: 363PSI,CLASS150
Surface Treatment: Black
Certificate: UL Listed / FM Approved / NSF 61
Application: Fire Protection,Waterworks,HVAC,Plumbing,GAS,Irrigation,or other piping systems

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Product Description

Products Details

How to distinguish beaded plugs and Plain plugs?

the edges of beaded plugs are more obvious and protruding, while plain plugs do not have such edges, so it is easy to distinguish beaded plugs and plain plugs from the appearance.

From the point of view of the use effect, the appearance effect of plain plugs is better than beaded plugs, because oplain plugs are easier to make the end of the pipe very smooth and integrated.

But from the installation point of view, beaded plugs are better than plain plugs, because beaded plugs have a protruding edge, so it can avoid too many plugs into the pipe and can not rotate out, or broken teeth, excessive rotation problems, so installers prefer beaded plugs when installing, and consumers prefer the appearance of ordinary plugs.

Finally, choose which pipe plug to purchase, and you also need to distribute and purchase according to market demand.

Product Drawing

Size L B S PCS/ Size L B S PCS/
mm mm mm CTN. mm mm mm CTN.
1/4” 15.5 10 6 2400 1   1/2” 31 21 22 200
3/8” 17 10 7 2200 2” 36 25 26 120
1/2” 22.5 13 10 1400 2   1/2” 40.5 26.5 30 72
3/4” 24 14 12 800 3” 45.5 29.5 34 64
1” 27 16.5 15 500 4” 57 38 44 36
1 1/4” 30 20 18 300 6”


What are the types of threads?

NPT is a general purpose American standard tapered pipe thread with a 60° tooth shape angle.

PT teeth are imperial tapered threads with a tooth angle of 55°, which is most commonly used in seals.

Inch pipe threads are fine threads, because the depth of the teeth of the coarse thread will seriously reduce the strength of the cut thread outer diameter pipe.

PF teeth are tubes with parallel threads. G is a 55 degree non-threaded sealed pipe thread, belonging to the Wyeth thread family. Marked G stands for cylindrical thread, G is the general term for pipe thread (Guan), and the division of 55 and 60 degrees is functional

ZG is commonly known as pipe cone, that is, the thread is processed by a conical surface, and the general water pipe joint is like this, and the old national standard is marked as Rc
Metric threads are represented by pitch, and US imperial threads are expressed by the number of thread teeth per inch, which is their biggest difference,

Metric threads are 60 degree equilateral shapes, imperial threads are isosceles 55 degree tooths, and American threads are 60 degrees. Metric units are used for metric threads, and imperial units are used for US imperial threads.
The pipe thread is mainly used to connect the pipeline, and the internal and external threads are closely matched, and there are two kinds of straight pipe and main pipe. The nominal diameter refers to the diameter of the pipe to which it is connected, and obviously the thread diameter is larger than the nominal diameter.
1/4, 1/2, 1/8 is the nominal diameter of the imperial thread in inches.

Application and Case

Products are used in fire protection system, water system, HVAC system, plumbing, gas system, irrigation system, etc.These products are used in many projects , such as Beijing Airport, Shanghai World Trade Center, Canton Tower and other famous landmark projects.