|Swarf, Mostly!||17/09/2021 19:41:14|
|646 forum posts|
I understand that gas pipe is colloquially referred-to as 'barrel' because the original town gas networks re-used the barrels from Government-surplus musket barrels from the Napoleonic Wars. (Or is this an urban myth? )
So, question #1: is it improper to also refer to water pipe as 'barrel' ?
Question #2: is galvanised water pipe galvanised on its interior as well as its exterior?
Engineering history can be obscure but interesting. For instance, why is the outside diameter of nominal 1½" pipe actually 1 and 29/32 inches?
Edited By Swarf, Mostly! on 17/09/2021 19:42:57
|Dave S||17/09/2021 19:47:02|
|363 forum posts|
I think this one is because pipe sizes are measured for the bore.
Makes sense if you need to know how much stuff will flow down a pipe I think
|662 forum posts|
If you know of a safe way to hot dip galvanise only the exterior, run down to the Patent Office and register the idea.
2422 forum posts
From memory of purchasing , the only barrel word I used was for barrel nipples. Thread each end .
|Paul Lousick||17/09/2021 23:42:32|
|2018 forum posts|
I am in Australia and never heard of pipe being referred to as barrel. The pieces of old water pipe that I have are galvanized on the inside as well as the outside. Otherwise they would rust.
Pipe is sized by its bore and as mentioned, originally used for calculating the flow of liquid thru it. The outside of pipes are a constant diameter to allow pipes with different wall thicknesses to screw into a common threaded hole (tees, elbows, valves, etc) Therefore the designation of a nominal bore size, not an exact bore size. Thicker walled pipes are required for higher pressures. Pipe is sized by its nominal bore and a schedule that specifies its wall thickness. Schedule 40 is the size used for common water pipe for homes.
Tube is specified by its OD and wall thickness (gauge size).
Edited By Paul Lousick on 17/09/2021 23:45:44
|Martin Connelly||18/09/2021 08:52:22|
2125 forum posts
British Standard Pipe (BSP) has a standard wall thickness, it is the size where the bore most closely matches the nominal size. It also came in lightweight. Both schedule 40 pipe and standard pipe were generally the minimum wall thicknesses to use for threaded pipes. Lower wall thicknesses were used to save weight and cost when they could be welded. For some ANSI standards (eg ANSI B36.10) schedule 40 is sometimes referred to as standard and sometimes the equivalent of schedule 80 is X Strong, there is also XX Strong. Pipe is designated as NPS or NB which are nominal pipe size and nominal bore which lets you know what to expect to some extent but you need tables to know exactly what you are going to get with any of these pipe designations.
The term barrel nipple only seems to apply to a nipple with an unthreaded centre section with a tapered thread either side, the result being a barrel shape to the side view. When there is no unthreaded centre section what you have is called a close taper nipple, you also get parallel nipples.
|Nicholas Farr||18/09/2021 09:15:28|
3329 forum posts
Hi, I agree with Martin with regards to barrel nipples. All the galvanized pipe that I've ever seen has been galvanized both inside and outside (That is when it is new)
Anyone remember running joints in pipework?
Edited By Nicholas Farr on 18/09/2021 09:19:45
|Jim Nic||18/09/2021 11:58:32|
378 forum posts
A little ampification on the nature of pipes:
1) Pipe is made of a long hole surrounded by metal or plastic centred around the hole.
|larry phelan 1||18/09/2021 18:44:52|
|1172 forum posts|
Makes more sense than many other posts !
1346 forum posts
Jim is right.
Once you have a hole you can do anything with a pipe, or tube. You can make it smaller, larger and even turn it in side out (if the material allows you to do so). The latter was a party trick at the BSC Corby research labs.
A couple of comments: Pipe, tube, can be made from welded strip (seamed) or bar that has had a crack induced up its centre (seemless). The high pressure boiler tube we produced was actually made from strip (it was beautful stuff). Seemed tube has a very consistent wall thickness but the control on diameter can be poor. The converse is true for seemless tube.
|Russell Eberhardt||18/09/2021 19:53:11|
2728 forum posts
Just be careful how you ask for pipe in France!
|Chris Gunn||18/09/2021 19:55:13|
|429 forum posts|
JA, just seen your reference to working at Corby, did you work in the DR&TD? if so which department? did you know anyone in the Control Systems section?
Chris Gunn, DR&TD, 1969-73.
|1697 forum posts|
Ha Ha yes.😊
1346 forum posts
I have sent you a PM.
|448 forum posts|
Not so much as a peep from me.
|Peter Ellis 5||19/09/2021 22:34:58|
|101 forum posts|
I was intrigued to discover that, in otherwise all metric Croatia, when I wanted pipe to make up pipe clamps, I had no difficulty, as it was all clearly marked 1/2 ¨ 3/4¨, etc. None of it was metric.
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