Fitting Selection Guide
Pipe fittings are available in various shapes, sizes and materials. Used
to connect pipes of different lengths and sizes, these pipe fittings and
flanges should make the right connections. Pipe and pipe-fittings are
produced from a various materials for the transport of wide variety of
solids and fluids. The wrong pipe fittings can lead to many problems
- unwanted flow restrictions and
- extra cost
The proper pipe fittings and flanges let your equipment do the work
that you intend it to do. The various types of pipe fittings include
adapters, bulkhead fittings, plugs, rigid couplings, flexible couplings,
90 degree elbows, 45 degree elbows, reducing elbows, flanges, nipples,
concentric reducers, eccentric reducers, side outlet tees, standard
tees, reducing tees, bullhead tees, unions, standard wyes, reducing wyes
and many more. You should select the right fitting for your application
among the wide range of fitting types and sizes offered.
Common points to consider:
The integrity of any fitting for proper functioning depends upon the
Selecting Your Pipe Fittings:
- Selection of correct components or fittings appropriate for the
- Careful preparation and cleaning
- Careful installation and assembly
- Correct tightening and loading
The points to consider are as follows:
Some popular fitting types:
- Consider the Tubing Used: For instance, barbed fittings
work better in flexible tubing while compression fittings work best
with rigid tubing.
- Determine Material Compatibility: Material selection
plays a vital role in the proper working of fittings. There are
certain fluids which are not compatible with fitting material and
these fittings cause leakage or system damage. It is very essential
to check the material compatibility of your fluid with any
- Check Temperature and Pressure Conditions: Appropriate
temperature and pressure ratings are needed for proper operating
conditions. It is necessary to know whether the fittings are capable
of performing at their maximum temperature and maximum pressure
ratings because most fittings cannot perform both the task
Pipe Thread Sizes:
They slide into soft tubing. For
low-pressure installations, tubing elasticity holds the tubing onto
Threaded Pipe Fittings:
These are the most commonly used
fittings based on certain standards. For instance, there are
threaded fittings of pipes in BSP (British Standard Pipe), NPT
(National Pipe Taper), UNF (Unified Fine Thread) sizes for
permanent, high-pressure pipe connections.
They are considered to be
quick-disconnecting fittings which are used with pipes and hoses.
For instance, you can connect a female coupler to a male adapter and
for a secure connection, pull down the arms. These fittings are
capable of withstanding high-pressure applications.
Quick Disconnect Fittings:
These fittings make and break
tubing connections without separating tubing from fitting.
These fittings are designed for
HPLC and other high-pressure applications and they can withstand
pressures as high as 1000 psi.
These fittings have a nut that
compresses rigid tubing against fitting body and are mainly used for
This is a very important consideration for any pipe fitting. All pipes
were manufactured with specification of a standardized outside diameter
(OD) and wall thickness which in turn implies that the nominal pipe size
is approximately equal to the inside diameter (ID). Nowadays, various
thread configurations are used. We give below an example of British
Standard Pipe (BSP) fittings for connecting systems that use both NPT
and BSP thread configurations. The table shows a comparison of these two
To sum up: Selection criteria for buyers:
Threads per inch
- Pressure Ratings
- Design and operation
- Safety information
Before purchasing pipe fittings and flanges, certain questions need to
be answered for that particular pipe fitting and the manufacturer who is
manufacturing that particular fitting. Some of these questions are as
- Can it handle pressure?
- Can it handle high temperature?
- Does it have proven long-term performance?
- Are the joints or seals reliable?
- Can it be fitted properly?
- Does it have confidence of manufacturers?
- Can it withstand outdoor storage and ultraviolet rays?
- Can it resist punctures and abrasion?
- Does it have widespread approval and acceptance from inspectors
- Does it have quality and value?
The more the number of YES, the better is your product.