What does NH mean in pipe thread?

National Standard Thread
NH/NST. NH stands for National Hose and NST stands for National Standard Thread. This is often referred to as “fire hose thread” because fire departments use it the most. It’s popular on many fire hydrants and accessories.

What is a NH coupling?

The most common thread type in use by fire departments today is NST or National Standard Thread. It is often referred to as “fire hose thread”. NST also goes by the initials NH or National Hose. This allows a female coupling to thread onto a NPT fitting without being a permanent connection.

What is an NH fitting?

National Hose (NH) is considered a “straight” thread which means the threads are consistent from tip to collar and the seal is made with the gasket inside the female coupling mating against the square face of the male coupling. The threads do not make the seal, they merely hold the two fittings tightly together.

What is the difference between NST and NH threads?

NST also goes by the initials NH or National Hose. It can even be referred to as NHT or National Hose Thread but NST or NH is more common these days. NH = NST. Fire hoses with National Pipe Straight Hose Thread (NPSH) has the same threads per inch as National Pipe Thread (NPT) but the threads do not taper.

Can NPT and NPS be used together?

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). While NPT and NPS threads will engage, they do not seal properly with each other.

Are Fernco couplings code?

It is my understanding that flexible PVC couplings (e.g. Fernco) meet the definition of Mechanical Joint in the international residential code. The 2015 IRC prohibits the use of Mechanical Joints on PVC couplings above ground “unless otherwise approved”.

What is the difference between IPT and NPT?

NPT or IPT pipe threads are tapered, Compression Fitting Threads are Parallel. NPT (National Pipe Threads) also abbreviated as IPT (Iron Pipe Threads) are tapered so that as you tighten NPT male and femal fittings the threads wedge themselves ever more-tightly together.

What are the two main types of fire hydrants?

For most intents and purposes, there are two types, wet and dry barrel hydrants, in addition to standpipes. These have a different structure and mechanism depending on the surrounding conditions.

What is hydrant and its types?

A fire hydrant is a pipe that allows water to flow from a water main with the control of a valve in order to put out a fire. Fire Hydrant Protection System is designed to fight fire of huge proportions, in all classes of risks. Dry barrel and wet barrel are the two kinds of Fire Hydrants.

What is the difference between NPT and NPS thread?

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. While NPT and NPS threads will engage, they do not seal properly with each other.

What are the coupling threads for NH and NPSH?

      National Standard         National Standard              National Pipe Straight Hose             National Pipe Straight Hose      NH or NST NPSH or IPT NPSH or IPT NPSH or IPT Size ODM TPI ODM  TPI 3/4″ 1.375 8 1.035  14 1″ 1.375 8 1.295  11.5

What are the dimensions of a NHR coupling thread?

NPSH, NH and NHR Nipples and Coupling Swivels Hose Coupling Threads – Dimension Chart *** All dimensions are given in inches. Nom. Size of Hose

What kind of threads are compatible with NH / NST?

NH/NST (National Hose/National Standard) threads are only compatible with other NH/NST threads. Male NPSH (National Pipe Straight Hose) threads are compatible with female NPSH threads. Female NPSH threads are compatible with male NPSH, NPT, NPTF, and NPSM threads. For technical drawings and 3-D models, click on a part number.

What’s the difference between NH and NST in fire hoses?

It is also called National Standard Thread (NST) or National Hose Thread (NHT). It is often referred to as “fire hose thread”. NH, NST and NHT are different abbreviations for the exact same thread. The female and male side of a fire hose coupling with NH threads will only connect to fittings, nozzles or hoses with the same threads.