Hose

Hose► Product

Hose Barb to Male NPS Adapter.

Fitting, Pipe, Hose Barb, NPS, NPSM, NPSH

Hose► Book page

 Comparison of hose stock types

Chemical name

Neoprene

Nitrile (Buna-N)

Butyl

Hypalon

EPDM

CPE

ASTM-SE designation

SC

SB

R

TB

R

None

SAE J14 & SAE J200

BC

BG

AA

CE

AA

None

Flame resistance

Very good

Poor

Poor

Good

Poor

Good

Petroleum base oils

Good

Excellent

Poor

Good

Poor

Very good

Diesel fuel

Good to excellent

Excellent

Poor

Poor

Poor

Very good

Resistance to gas permeation

Good

Good

Outstanding

Good to excellent

Fair to good

Good

Weather

Good to excellent

Poor

Excellent

Very good

Excellent

Good

Ozone

Good to excellent

Poor for tube
Good for cover

Excellent

Very good

Outstanding

Good

Heat

Good

Good

Excellent

Very good

Excellent

Excellent

Low temperature

Fair to good

Poor to fair

Very good

Poor

Good to excellent

Good

Water-oil emulsions

Excellent

Excellent

Good

Good

Poor

Excellent

Water-glycol emulsions

Excellent

Excellent

Excellent

Excellent

Excellent

Excellent

Diesters

Poor

Poor

Excellent

Fair

Excellent

Very good

Phosphate esters

Fair for cover

Poor

Good

Fair

Very good

Very good

Phosphate ester based emulsions

Fair for cover

Poor

Good

Fair

Very good

Very good

American National pipe (NPT, NPS), Like British Standard Pipe (BSP), is designated by trade size, rather than actual diameter, as shown in the table below.

There are two basic types of National pipe threads:

  • NPT: National Pipe Taper
  • NPS: National Pipe Straight

NPT threads are also sometimes referred to as

  • MIP (Male Iron Pipe)
  • FIP (Female Iron Pipe)
  • IPT (Iron Pipe Thread)
  • FPT (Female Pipe Thread)
  • MPT (Male Pipe Thread)

Note that these references are somewhat casual, and might possibly be used in reference to NPS instead of NPT.

Both NPT and NPS have the same thread angle, shape, and pitch (threads per inch).  However, NPT threads are tapered and NPS threads are straight (parallel).  Both threads have a 60° included angle and have flat peaks and valleys (this is a Sellers thread form).

If you've worked with pipe much at all, you've probably noticed that the size of the pipe isn't really what size the pipe is.  Unlike tubing, which is generally specified by its OD, or hose, which is generally specified by its ID, pipe is specified by something else... its Trade Size.  So when you say "3/4 pipe," you're actually saying "pipe whose OD is a little more than an inch, and whose ID is about 53/64."  -that is, if you are talking about schedule 40 pipe, which is generally what is used for most plumbing applications.

Pipe dimensions are specified by trade size and schedule, according to the following table.  Note that while British Standard Pipe dimensions are similar, they are not equivalent to the American Standard Pipe Sizes.  See NPT vs. BSP Pipe for thread comparisons.

Hose► Fitment

NST (National Standard Thread) is a definition of actual diametral thread dimensions and pitches for various fittings for adapting nominal hose and pipe sizes.

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