Etiket Arşivleri: elbows

Pipe Fittings

Pipe Fittings
Purpose of Pipe Fittings
Plumbing fittings have different shapes which allow rigid straight pipe to change both direction and diameter.
Elbows
Used to change the angle or direction of the pipe run.
The most common elbows come in 90 degree and 45 degree turns.
The sweep of the fitting describes how fast a transition or change in direction is made.
Street Elbows
One end of the fitting has male threads and the other end has female threads.
Street elbows are common in galvanized steel and copper pipe.
They are convenient because they do away with the need for a nipple and work well in tight quarters.
Tee or T-fittings
Allow for branch lines.
They are shaped like the letter T.
DWV tees are known as waste or sanitary Ts.
In these fittings the intersection is slightly curved in order to avoid clogs. Gradual bends are best for smooth flow of waste.
Couplings
Used to join two straight pieces of pipe of the same diameter.
Reducers
Used to join pipe of different diameters.
Galvanized steel reducers are called bell reducers because they look like a bell.
All reducers make a gradual transition between different diameters of pipe and therefore they take up considerable space
Bushings
Used to make the diameter of a pipe fitting smaller.
They differ from reducers in that they make abrupt changes in diameter and take very little space.
Two examples of galvanized steel bushings are
face bushings, which take the least amount of space, and
hex bushings which can be tightened with an adjustable wrench.
Unions
Used to join pieces of pipe where pipes cannot be turned or when a piece of equipment may have to be removed for maintenance or replacement.
Adaptor fittings
are used to change the end of a non-threaded pipe to male or female threads as needed.
Adaptors are commonly used in copper and plastic plumbing jobs.
For example adaptors are used to convert from a PVC glue connection to a threaded connection or
from a copper soldered connection to a threaded connection.
Male adapters and female adapters are both common.
Caps
Used to close the end of a dead end pipe.
Plugs
Close an opening on a pipefitting normally used for inspection and cleanout.
Nipples
Short lengths (under 12″) of pipe threaded at both ends.
Wyes
Pronounced like the letter Y
Used primarily to gain inside access to DWV systems.
Valves
Devices that control the flow of liquid or gas through or from a pipe.
Types of plumbing valves are:
compression valves,
ball valves,
sleeve-cartridge valves,
ceramic disc valves
and more
PVC Fittings
PVC fitting come in a wide variety of configurations.
They many be glued (S) or threaded (T) or both.
Glued fittings are referred to as “slip” fittings.
When specifying a PVC fitting the size and type of connection are specified. Some examples are:
¾” x ½” ST Ell – A reducing ell with a ¾” slip x ½” thread
¾” x ¾” x ½” SST Tee – A reducing tee with a threaded outlet
¾” x ½” SS Bushing = A bushing with slip connections.
Copper Tubing Fittings
Copper tubing use compression fittings.
Fittings are available to adapt from compression to IPS and from compression to soldered fittings.
Common fittings include couplings, ells, and tees.
Valves and Hose Bibs
Valves are used to control the flow of water or other fluids in a plumbing system.
Common types of valves include the following:
A gate valve is a valve situated between the point of connection and the rest of the plumbing system.
It usually remains wide open, but can be shut down in case repairs or additions have to be made to the system.
A gate valve is not designed to be opened and closed on a regular basis.

A check valve allows the fluid in the pipe to flow in one direction only.
Check valves are used in water wells to prevent the backflow of water.
There are two basic types: swing or flapper and lift check valves. Both work automatically.

A globe valve is a valve used when frequent adjustment of the flow rate is necessary.
It is a compression-type valve with a disk or washer that is compressed into a seat to form a tight seal. Repair is made by replacing the stem washer or disk.

A hose bib is a threaded exterior faucet that allows for the attachment of a garden hose or appliance hose.


Friction Loss in Piping System

In this experiment we have tried to understand how the pipe length, fluid flow rate, bending, elbows, and valves are affecting the head of the fluid that is flowing in side a particular type of pipe such as steel.

In that experiment we have seen that the flow rate causes head change, also the head losses are changing on a particular fitting or in a straight pipe. This is the case that was expected by looking the head loss equations, that is caused by the interaction of the fluid molecules with the inner side of the pipe surface molecules. In the experiment we have found that the friction factor or the fanning factor and the K values are changing by the change of the fluid flow rate by inversely. That is caused by the interaction of the fluid molecules and the pipe surface molecules as mentioned previously, when the fluid moves faster and faster the interaction between them is getting lower and by the consequence of this the factors values getting lower, but in the other hand the head losses are getting larger than the slower flow rates, that is caused by the velocity which is effect by the power of 2, and that is why the flow rates cause larger changes in head losses. For the flowing fluids velocity change cause change of Reynolds’s number, that determines the type of flow, weather it is laminar or turbulent, which is directly effects the characteristics of the flow, and changes all values, constants and other variables that are effecting the flow, and the flow regime. If we look for the overall changes in head losses while friction factor is getting smaller, since velocity getting larger by the square power the head losses getting larger when the flow rates increase. Other factors for the head losses in a piping system are the minor factors that are caused affecting the head loss while a fluid flows in a pipe, but not so much effectively changes the head of the fluid. They caused small head losses in the system, that is why they are called minor factors. Also by looking our experiment we can also figure out the effects of these fitting on the system. For the elbows, expansion or contraction parts, bends there is not so much head loss, but this is not the mean of that we can neglect the effect of these. When the number of these fittings are much enough, they can cause very effective head losses. The valves are much effective for the head loss than the bending or expansion, but in our data there is an inconsistency for the gate valve versus different flow rates, this can be occur by the U tube which was connected to the each end of the gate valve, there can be excess air, which can change the pressure of the water, and can make us to read incorrectly the value of the piezometer.

In conclusion we have make some observations during the experiment, and have taken some notes about the experiment, also after the experiment, by calculating the required values we have get an idea about how the friction effects the flow, and also the effects of pipe types and the fittings on the flow. Moreover we have learned how the flow type and the flowing material’s viscosity affecting in a flow.