Pipe Threads

[Weseng]

I have a customer who is requiring NTP pipe threads. Specifically NTP3/4-14 and also NTP3/8-18. I suspect a typographical error so I checked Machinery's Handbook, 25 Edition and lo and behold, on page 1778, there is mentioned an NTPF thread. However, I suspect this is another typo??
Has anyone out there ever heard of an NTP thread?

 

[19488]

NATIONAL PIPE THREAD (TAP)
YES there is NPT and NPTF (fine thread)
Example:
3/8" NPT drill size=.5625 NPTF=.5781
Abreviation which you have used NTP should be NPT or is from Francophone.

 

[Weseng]

Dear 19488
I am well aware of the entire series of NPT, NPTR, NPSC, NPSM, NPSL, NPSH, NPTF, PTF-SAE SHORT, NPSF, and NPSI. However, I am looking for any reference to NTP. Pardon my ignorance, but what is Francophone?
Thanks.

 

[MintJulep]

NTP = National Tapered Pipe thread

Suffex of F at the end means female, M for male.

Fracnophone is "A French-speaking person, especially in a region where two or more languages are spoken."

However 19488 is refering to the difference in order of subjects and verbs in English versus French grammer. For example the "International Standards Organization" is abbrevated ISO in English but OIS in French for "Organization International du Standardization"

 

[mrainey]

Just for fun, I searched for 1/4-18 NTP thread on Google, and got several hits. NTP appears to be a valid designation for some threads associated with tube fittings.

 

[Cockroach]

The terms "francophone" and "anglophone" are Canadian and refer to the pluristic society between French and English speaking people(s). More specifically, francophone generally references people from the province of Quebec relative to the rest of english Canada. However, Canada is a bilingual country with both offical languages being French and English, so francophone may also apply to those who maintain the culture in other french speaking communities, Acadians on the East Coast for example.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[CoryPad]

Contrary to MintJulep's post, ISO is not an acronym. The International Organization for Standardization chose for its symbol the Greek word ISO because it means "same", which is what standardization is.


Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[MintJulep]

Cory is correct.

Excerpted from

http://www.iso.org:

Introduction

Why standards matter
Who ISO is
What ISO's name means
How it all started
What 'international standardization' means
How ISO standards benefit society
The hallmarks of the ISO brand
ISO and world trade
ISO and developing countries
How to recognize an ISO standard
The big, wide world of ISO standards
What makes ISO 9000 and ISO 14000 so special
What makes conformity assessment so important
Where to find information on standards
Who can join ISO
How the ISO system is managed
How the ISO system is financed
How ISO decides what standards to develop
Who develops ISO standards
How ISO standards are developed
When speed is of the essence
ISO's international partners
ISO's regional partners
Specialist liaisons
Special products


Why standards matter


What if standards did not exist?

If there were no standards, we would soon notice. Standards make an enormous contribution to most aspects of our lives - although very often, that contribution is invisible. It is when there is an absence of standards that their importance is brought home. For example, as purchasers or users of products, we soon notice when they turn out to be of poor quality, do not fit, are incompatible with equipment we already have, are unreliable or dangerous. When products meet our expectations, we tend to take this for granted. We are usually unaware of the role played by standards in raising levels of quality, safety, reliability, efficiency and interchangeability - as well as in providing such benefits at an economical cost.

ISO (International Organization for Standardization) is the world's largest developer of standards. Although ISO's principal activity is the development of technical standards, ISO standards also have important economic and social repercussions. ISO standards make a positive difference, not just to engineers and manufacturers for whom they solve basic problems in production and distribution, but to society as a whole.

The International Standards which ISO develops are very useful. They are useful to industrial and business organizations of all types, to governments and other regulatory bodies, to trade officials, to conformity assessment professionals, to suppliers and customers of products and services in both public and private sectors, and, ultimately, to people in general in their roles as consumers and end users.

ISO standards contribute to making the development, manufacturing and supply of products and services more efficient, safer and cleaner. They make trade between countries easier and fairer. They provide governments with a technical base for health, safety and environmental legislation. They aid in transferring technology to developing countries. ISO standards also serve to safeguard consumers, and users in general, of products and services - as well as to make their lives simpler.

When things go well - for example, when systems, machinery and devices work well and safely - then often it is because they conform to standards. And the organization responsible for many thousands of the standards which benefit society worldwide is ISO.



Who ISO is


ISO is a network of the national standards institutes of 147 countries, on the basis of one member per country, with a Central Secretariat in Geneva, Switzerland, that coordinates the system.

ISO is a non-governmental organization: its members are not, as is the case in the United Nations system, delegations of national governments. Nevertheless, ISO occupies a special position between the public and private sectors. This is because, on the one hand, many of its member institutes are part of the governmental structure of their countries, or are mandated by their government. On the other hand, other members have their roots uniquely in the private sector, having been set up by national partnerships of industry associations.

Therefore, ISO is able to act as a bridging organization in which a consensus can be reached on solutions that meet both the requirements of business and the broader needs of society, such as the needs of stakeholder groups like consumers and users.



What ISO's name means


Because "International Organization for Standardization" would have different abbreviations in different languages ("IOS" in English, "OIN" in French for Organisation internationale de normalisation), it was decided at the outset to use a word derived from the Greek isos, meaning "equal". Therefore, whatever the country, whatever the language, the short form of the organization's name is always ISO.

I wonder how long it took them come up with the concept of an acronym that is not an acronym?


However, my example is adequate to illustrate the point.

 

[metalonis]

1. The designation NTP is a colloquialism for NPT taper pipe threads.

2. An F suffix refers to a Dryseal pipe thread. It does not designate female thread.

3. An M suffix refers to a mechanical pipe thread. It does not designate a male thread.

 

[f100]

I think Metalonis is right.
In the early 1990ties I used NPTF in my offshore designs.
I had two good American Handbooks from ca 1980.
I first overlooked the pipe fitttings suppliers techical notes on threads, which I later found to be very useful.
By chance I stumbled over the NPTF in a "narrow" paper called "Strictly IC"- a society for non professional internal engine builders. I found the NPTF explined there.
From my handbooks I found:
N=American (National) Standard
P=Pipe
T=Taper
C=Coupling
S=Straight
M=Mechanical
L=Locknut
H=hose coupling
R=Railing fitting
But no F.
They denote the thread as "American Standard Dryseal Pipe Threads" and "Dryseal Pipe Thread" without stating it in short-form, the NPTF.
So where how did this F enter?
Well I could buy the standard. Better leave that discussion.
Before I come to the point,
Note that the British use P=parallel, not S for straight.
BSP=Britsh STANDARD PIPE
With no extra letter it is assuemd to be BSPP. (Normal for hydraulic oil fittings catalogs)
The BSPT is the brother of NPT. But still different.
The BSPT (T for Taper) is equal to the German R)
Both are based on the Whitworth Pipe Threads.
So is the Scandinavian National Standards too.
Especially be aware of the ANSI B1.1 UNF 7/8"-14 thread which is nearly equal to the BSPP 1/2 -14".
A fitting with the BSPP will enter the UNF with ease - and destroy it. You then need a new housing.
The UNF 7/8"-14 is a common drain port for pump/motor housings. The BSPP 1/2"-14 is even more common as a fitting's thread.
The BSPP 1/4"-19 and the M14 is another disaster pair.
Be aware.
Back to my point.
I am fed up with all the abbreviations used ouside the communities where it is more or less obvious.
Even in special trades/groups, the some abbreviations should be restated in form of writing. What do we have Word Processors for. Take for example what many of us sees daily. "Based on NT Technology". Read out it says:
"Based on New Technology Technology". Or did I miss something?
So in the next technical description we write: 1/2" NTPF (American Standard Dryseal Pipe Threads). Once at least when space allows. Yes, I did not explain ANSI or UNF.
ANSI= American National Standards Institute.
UNF= Unified National Fine, A fine machine thread according to ANSI standard B1.1-1974.
English is not my native language and this is not well proof read. It might not be perfect.
This was a few thoughts from Norway, the metric country where all carpenters order "two by four" (In Norwegin writing: "to tom fire&quotat the lumber yard and the bill says 48x98 (mm. When plained). "Tom" is hort for tomme=thumb.
Our inch is 26.3mm compared to the English of 25.4mm.
And we say "tomme" which means thumb. Why say inch when you mean a thumb's width. A foot is a foot long. Or?
I hope I have not exceded the limits for aceptable topics.
I can't help thinking we could make our profession more likeable and understandable to those outside who by chance might happend to come accross our conversations. And rethink the daily obviousness for our own sake.

 

[Cockroach]

....f100....5th line from the bottom:

I missed something, are you saying that "your inch" is 26.3 mm, not 25.4 mm as in the English/American system? You're messing with my mind now!

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[Neilmo]

No, no, Cockroach, I think what f100 is saying is, that because he only gets 98mm of timber when he actually ordered 101.6 (4" x 25.4), his inch has effectively become = 101.6x25.4/98 = 26.3mm. Thats my take on it anyway!

Regards,
Neilmo

 

[Cockroach]

Check out the website, "

http://www.onlineconversion.com".

Noting one American foot as an international standard which equals 1.0765373 ft (Norway), and the same American/Int'l foot of 304.8 mm then:

(1.0765373 X 304.8)/12 = 27.34405 mm/in(Norway)

I guess this sort of explains why Norweigen women smile so much!

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[Weseng]

Thank you all for the interest and information on my Query. I just got notification from my customer. The NTP is, as I suspected, a typo and should have been NPT.
Thanks again.

 

[f100]

Thanks to Hueston and Neilmo for their interest.
Good point made about getting less than expected!
Sorry but I have to admit that I was depending on my memory which failed me a little.
I have not checked the official figure, but is pretty sure now the the Norwegian Inch (Tomme)is 26.15 - twentysix point fifteen. That destroys the Neilmo ratio of 101.6/98. Sorry.
The anoying side of this for weekend carpenters, at least, is that since they quit making the 4x4 tomm =(26.15mm x 26.15mm), they also quit making the "box" as such. Now they deliver as standard ony the 48mmx98mm. Two of these make 98mmx96mm, Not 98x98. So we are left with 2mm les on one side. I had expected a 50mmx100mm to be the standard. They sure have some explaination I expect.
The "tomme" formally was abandoned in favor of the matric system in 1910+/-5. But was used in the building industry together with the meter well into the 70ties.
Standard lengts were made to units of 300mm, starting at 1.8m. This was an adjustment from the foot.
Altough tape measures have been around since the 50ties, many still use the old "tommestokk" or "Thumb/Inch Stick".
This is folded together in 6 parts and has 5 hinges.
It is 5/8" wide and 3/8" thick made of wood or plastic.
One half used to be cm and the other Norwegian inch or Enlgish inch. So the inch side was printed London or inch for the English inch and NORSK for Norwegian inch/tomme to state the difference. The Meter side says METER.
The Norwegian inch/tomme units are still around. When I line up the millimeter marks I read 993.7mm at the 38tomme mark on my "just like new" Norwegian thumb stick. This makes one tomme=26.15mm. Compared to this 38"x25.4mm=965.2. So why bother with this outdated stuff.
As I said. They are still around in drawers and tool boxes. And if you happened to get the wrong one, it will make a difference. I checked my local hardware store. They only have the the English inch/meter or the meter and the two meter only. The one or two meter sticks are often more handy than a tape. I use all three.
Not sure the folded stick type is used in America/Canada.
So this is meant as a warning.
Mechanical shops today use English inches only and know the difference. But a visitor from abroad just there to check a few measurements before hurrying off, might be handed a nice and clean spare tumb stick from the foremans drawer as it shows inches of some kind. It could lead to a bad fit.
Even with about 100 years with the meter, we buy an outboard with an 15" pitch propeller and a 26" TV. And the wheel rims are still 13-14-15-..inches in diameter.
And the TV news informs us that the plane was at 10000 feet, when allmost all other distances are in meter or km.
And for those with lots of money: A Norwegian Billion is 1000000 millions as "Milliard=1000xMillion". The American Billion is our Milliard. So we have no Billionaires. This really could make a difference!!.
As I said: The intension was good.