THREAD TYPES FOR PIPE FITTINGS 1

[Alaa1992]

Hy All
I want to ask about the exact difference between the terms: SCREWED and THREADED for a given steel pipe fitting.
i have faced the two following technical nominations for a cap and the terms MALE (M) and FEMALE (F) are missed (at least to identify if that cap is either MALE or Female (Plug)):
1) CAP, THRD, 3000LB, A105
2) CAP, FS SCR'D, 3000LB, A105
So wath difference is supposed to be here in this case?
Thank you in advance

Alaa Edine SMAALI
Energy (Oil&Gas) Project Engineer

 

[MJCronin]

It has been my experience in the USA that the two terms are used interchangeably, regarding NPT piping systems.

Threads should comply with an ASME dimensional standard: ANSI/ASME B1.20.1 Pipe Threads, General Purpose

Do not mix up ISO and NPT threaded components ....

https://www.engineeringtoolbox.com/npt-national-pipe-taper-threads-d_750.html

MJCronin
Sr. Process Engineer

 

[mk3223]

The descriptions of #1 and #2 are equally correct. See ASME B16.11 for more threaded fittings.

 

[Alaa1992]

@mk3223@MJcronin

Thank you both for your answers
Regarding to this, how can i distinguish, in the abscence of an ISOMETRIC drawing(Symbols), and according to the nominations mentionned above, the thread side (Cap male or female)




Alaa Edine SMAALI
Energy (Oil&Gas) Project Engineer

 

[Artisi]

Cap is female thread, plug is male thread, just think in anatomical terms, a cap screws onto an externally threaded pipe, thereas, a plug screws into an internally threaded fitting - the very reason they are called male or female threads.


It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[Alaa1992]

@Artisi..
You mean that i should consider the first designation as a cap, The second as a plug/hex plug.?

Alaa Edine SMAALI
Energy (Oil&Gas) Project Engineer

 

[LittleInch]

The description should rule here, i.e. a CAP is a CAP, not a PLUG.

What is FS meant to mean?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Alaa1992]

@LittleInch
FS mean Forged steel (A105)..
Any way when you read #1 and #2 you will have doubt about cap or plug, especially, without indicating the thread side (Male/Female)
look at the attached PIC bellow.

Alaa Edine SMAALI
Energy (Oil&Gas) Project Engineer

 

[Artisi]

The fitting on the left is a cap, on the right a plug, where or what is the confusion?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[Alaa1992]

@ARTISI
Can you attribute please, to each of them, a technical description among #1 and #2 mentionned previously?

As Plugs and caps HAVE THE SAME FUNCTIONS, why many designers use these 2 (#1&#2) designations then? (I have faced them, not only for caps, but for also TEes and ECC/CONC reducers)

As you said, a cap is internally threaded, it is ok.
so when it becames externally threaded and screws into an internally threaded fitting, can we call it plug rather then cap? and instead of writing THRD, can we change it by SCR'D in the technical designation?




Alaa Edine SMAALI
Energy (Oil&Gas) Project Engineer

 

[LittleInch]

From ASME B 16.11

CAP

PLUG

@As per ASME B 16.11 the terminology is Threaded.

Internal threads or External threads.

"Screwed" does not appear in ASME B 16.11 and should not be used.

Unfortunately many designers don't actually read the actual code documents, but rely on word of mouth or years of doing it "their way"....


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Artisi]

Saying caps and plugs have the same function is a fairly meaningless statement, other than to say that a cap is used to close off the end of a threaded pipe, whereas a plug is used to close off a pipe fitting - both function as a termination point.
I am really at a loss trying to see what you are trying to establish, tradition is well established to what a cap is and what a plug is.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)