Fitting Types

Rc

Meaning: 
Same as BSPT, R
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The Rc thread is a designation for BSPT (British Standard Pipe Taper).  For example,

Rc 1/4

refers to the threaded end of a fitting or pipe which is 1/4 inch trade size (not actually 0.25 inches), and having British Standard Tapered Pipe threads.

Rp

Meaning: 
Same as BSPP, G
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The Rp thread is a designation for BSPP (British Standard Pipe Parallel).  For example,

Rp 1/4

refers to the threaded end of a fitting or pipe which is 1/4 inch trade size (not actually 0.25 inches), and having British Standard Parallel Pipe threads.

Ballcock

Meaning: 
A float-style fill valve
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Ballcock

From Wikipedia:

A ballcock (also balltap or fill valve) is a mechanism for filling water tanks, such as those found in flush toilets, while avoiding overflow. It was invented by Thomas Crapper.

It consists of a valve connected to a float by means of a lever, mounted near the top of the tank. The valve is connected to the incoming water supply, and is opened and closed by the lever which has the float mounted on the end. When the water level has risen to a preset fill line, the float forces the lever to close the valve and shut off the water flow.

When a toilet's handle is turned, a flapper valve is pulled upward by means or a rod or chain. It is designed to sink more slowly than the water, which will exit to the toilet bowl below, so that the tank may empty. As the tank water level drops, the float descends and actuates the fill valve. Water is fed to the tank to replenish its supply, and a smaller flow is directed into the overflow tube to refill the bowl.

Once the flapper valve closes, the water flow from the fill valve continues until the tank level again reaches the fill line. Should the float or valve fail and allow the water level to exceed the fill line, the water will pour into the overflow tube and out to the bowl.

These devices are sold at most hardware, plumbing supply, and home improvement stores.

Storz

Meaning: 
Sexless fire hose coupling
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Storz

The following is from Wikipedia

Storz is a type of hose coupling invented by Carl August Guido Storz in 1882 comprised of interlocking hooks and flanges. It is sometimes referred to as a sexless coupling, because rather than having a male and female end connected by screw threads, either identical end can be joined to any other end of the same size. This is also called hermaphroditic or two-way connection. Amongst other uses, it has been widely employed in firefighting applications.

To couple a Storz connection, the two opposing couplings are pressed together such that the hooks of each one are inserted into the slots in the flange of the other. Then they are rotated in opposite directions until they are tight, or latches engages. This creates a water-tight connection between the internal packing gaskets. To uncouple them, the latches are released and the couplings are turned in the opposite directions from coupling, and then separated when the hooks and slots are aligned. Special wrenches are designed for assisting with Storz connectors.

In the United States, fire engines typically carry LDH (large diameter hose) with Storz couplings on both ends for connections between fire hydrants and pumps. However, hydrants in the USA usually have threaded couplings and require an adapter to use with Storz. This is not the case in many other nations.

Guido Storz patented his coupling in Switzerland in 1890, and it soon became a standard for fire hydrants throughout much of Europe. However, it took nearly one hundred years before steamer ports on fire hydrants started to be converted to the Storz type in the United States. All major U.S. hydrant manufacturers now offer Storz as original equipment on their hydrants, to match the Storz couplings used by firefighters.

NAS

Meaning: 
National Aerospace Standard
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NAS

NPS

Meaning: 
National Pipe Straight
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NPS

NPS (National Pipe Straight) is a straight thread used for mechanical joints or where fluid sealing is accomplished by an o-ring or washer at the base of the threads.  NPS is a U.S. standard.

MIP

Meaning: 
Male Iron Pipe
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MIP

MIP is a comonly used shorthand designation for Male Iron Pipe (Male NPT).

AND

Meaning: 
Air Force-Navy Design Standard
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AND

AND is a sometimes-used synonym for AN.  An AND fitting is an AN fitting.

MPT

Meaning: 
Male Pipe Taper (NPT)
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MPT

MPT is a comonly used shorthand designation for Male Pipe Taper (Male NPT).

AS

Meaning: 
Aerospace Standard
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AS

The AS standards are authored by SAE (Society of Automotive Engineers).

AS standards cover a very broad range of hardware, tubing and pipe fittings being a small subset thereof.  One example of an AS standard document:

AS4395B  Fitting End, Flared, Tube Connection, Design Standard

 
Pipe Size
Pitch  (Threads/Inch)
NPT/NPS
BSP
 1/16"
27
---
 1/8"
27
28
 1/4"
18
19
 3/8"
18
19
 1/2"
14
14
 5/8"
---
14

 
Pipe Size
Pitch  (Threads/Inch)
NPT/NPS
BSP
 3/4"
14
14
1"
11 1/2
11
1 1/4"
11 1/2
11
1 1/2"
11 1/2
11
2"
11 1/2
11
2 1/2"
8
11

 
Pipe Size
Pitch  (Threads/Inch)
NPT/NPS
BSP
3"
8
11
3 1/2"
8
11
4"
8
11
5"
8
11
6"
8
11
8"
8
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