A pipe union consists of three parts – a nut, a female end and a male end. To make an effectively working pipe fitting, both the male and female ends are sealed together with the help of nuts. A female threaded fitting has threads on the inside, while in the male-threaded fitting, the threads are on the outside.
Full Answer
What is a pipe union?
What are the applications of pipe unions?
What is a female threaded fitting?
What happens when you pull stress on a pipe?
What are the two types of pipe unions?
Why are nuts used in a joint?
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How does a plumbing union fitting work?
A pipe union consists of three parts – a nut, a female end and a male end. To make an effectively working pipe fitting, both the male and female ends are sealed together with the help of nuts. A female threaded fitting has threads on the inside, while in the male-threaded fitting, the threads are on the outside.
Which way does a union go on a pipe?
Unions, swivel joints, etc., do not have a preferred direction of flow. The common practice of using male to male or female to female union connecting subs gives certain confirmation.
What is the purpose of a union fitting?
Pipe unions and couplings are both types of fittings that allow you to repair breaks in plumbing lines, but there's an important difference between them: A coupling makes a permanent connection, while a union makes one that can be separated and reassembled repeatedly.
How does a union PVC fitting work?
0:323:32How To Use Union Repair Fittings - YouTubeYouTubeStart of suggested clipEnd of suggested clipIt creates a permanent connection between two pipes. These are unions this union is slip. And thisMoreIt creates a permanent connection between two pipes. These are unions this union is slip. And this one is threaded the Union allows you to make a connection that's capable of being taken apart.
Is there a flow direction on a union?
RE: Flow Direction Through a Pipe Union No. In some applications, it is common to flow from the nut side to the external thread side, but this is not required. There are also applications where it may make sense to flow the other direction.
What is the difference between a union and a coupling?
The basic difference between a coupling and a union is that a coupling is for joining pipe to pipe or pipe to a swedge. A union is made for joining and disassemble of a part of a piping system (a steam trap or control valve, etc) for maintenance or replacement.
When should a union in a piping system be used?
Unions shall be installed in the water supply piping not more than 12 inches (305 mm) of regulating equipment, water heating, conditioning tanks, and similar equipment that requires service by removal or replacement in a manner that will facilitate its ready removal.
What is the purpose of union fitting in water supply?
Unions facilitate the removal and repair of system components and consist of one fitting having a swivel nut which attaches to the other fitting which has a male threaded adapter with a flange or compression type seal.
How do you join two threaded pipes together?
0:001:43How to Make Threaded Pipe Connections - YouTubeYouTubeStart of suggested clipEnd of suggested clipWhen using liquid thread sealant brush the sealant all the way around the thread the sealant willMoreWhen using liquid thread sealant brush the sealant all the way around the thread the sealant will dry. And slightly expand to create an airtight seal between the pipe. And the fitting a combination.
How do you stop a union from leaking?
If the union is leaking from either solder joint, disconnect the union and heat the leaking joint to melt the solder. Slip the union off, spread new flux and re-solder it. If the union is joining copper and galvanized steel pipes, it should be a dielectric union.
How do you install PVC union fittings?
1:187:28Repairing Cracked PVC Pipe with a Union - YouTubeYouTubeStart of suggested clipEnd of suggested clipTo half turn to make sure the glue. Is spread out evenly inside the pipe until only take 30 secondsMoreTo half turn to make sure the glue. Is spread out evenly inside the pipe until only take 30 seconds or so to dry. And you're going to need to do that with the other side. So. Take your glue on.
Are PVC Unions water tight?
On their own, without any type of adhesives or lubricants, PVC fittings will fit fairly snugly. That being said, the connection between the pipe and the fitting will not be watertight.
How do you install a galvanized pipe union?
Place a 1/4-inch bead of liquid pipe dope around the center of the pipe threads on one side of a galvanized steel pipe.Place the end of the pipe into the top of the galvanized steel union fitting and turn the fitting clockwise until tight.Place a pipe wrench around the fitting and turn it clockwise until very tight.More items...
What is Union end?
Union. Union connections employ a female threaded collar nut that threads on to a male threaded end connection of the valve. Typically union connections fasten stubs of another connection type, like welded, glue, or threaded, onto the valve. Those connections then are attached to the pipe.
When should a union in a piping system be used?
Unions shall be installed in the water supply piping not more than 12 inches (305 mm) of regulating equipment, water heating, conditioning tanks, and similar equipment that requires service by removal or replacement in a manner that will facilitate its ready removal.
Where will you use union or flange Union joint?
And Pipe unions are generally used on threaded pipes and used on pipes with small pipe diameters. Larger pipe diameters are generally connected by means of flanges, etc., which are also easy to disassemble.
What is pipe fitting?
Pipe fittings are components used to join pipe sections together with other fluid control products like valves and pumps to create pipelines. The common connotation for the term fittings is associated with the ones used for metal and plastic pipes which carry fluids. There are also other forms of pipe fittings that can be used to connect pipes for handrails and other architectural elements, where providing a leak-proof connection is not a requirement. Pipe fittings may be welded or threaded, mechanically joined, or chemically adhered, to name the most common mechanisms, depending on the material of the pipe.
What is concrete pipe fitting?
Concrete pipe fittings are available in a variety of styles suitable to their application in large civil projects such as storm-water control. Aside from the typical wye connections, specialized fittings include utility hole portals and various styles of vaults. Typical connections use shouldered ends on the fittings which mate with counterparts on the receiving pipes. A rubber gasket provides for a leakproof joint.
What is a hubless pipe?
Fittings for cast iron pipe fall under hubless and bell-and-spigot styles. Hubless designs rely on elastomeric couplers that are secured to the outer diameters of the pipe or fitting by clamps, usually a stainless steel band clamp that compresses the elastomeric material and forms a seal. These hubless or no hub designs are sometimes referred to as rubber pipe couplings or rubber plumbing couplings and are especially popular for transitioning from one material to another—from copper to cast iron, for instance. Bell-and-spigot, or sometimes, hub-and-spigot, fittings are joined today primarily with elastomeric gaskets that fit inside the bell and accommodate the insertion of the plain pipe end or fitting. Older systems before the 1950s were caulked using a combination of molten lead and a fibrous material such as oakum. Cast iron pipe is sometimes joined with bolted flanges, or in some cases, mechanical compression connections. Flanged joints employed in underground applications can subject the pipe to settlement stresses unless the pipe is adequately supported.
What is threaded flange?
The threaded flange is suitable only for low- to medium-pressure applications.
What is aluminum pipe used for?
Aluminum pipe is also a popular choice for use in creating handrails, and a host of fittings for structural applications are available, both weldable and slip on/clamp-on varieties.
What is a bell and spigot?
Bell-and-spigot, or sometimes, hub-and-spigot, fittings are joined today primarily with elastomeric gaskets that fit inside the bell and accommodate the insertion of the plain pipe end or fitting. Older systems before the 1950s were caulked using a combination of molten lead and a fibrous material such as oakum.
What are the different ways flanges seal faces?
Flanges can incorporate several different methods to seal adjoining faces, including O-rings, seal rings, and gaskets. Seal rings provide an especially tight joint and for the same bolt stress applied to a flat-face gasket, can resist a higher pressure.
Why use pipe unions?
They can be used when it comes to inserting regulating and metering devices regardless of the plumbing application. Great for managing water usage efficiency, for example. Perhaps the most important aspect of pipe unions is that they are versatile enough to join different sizes.
What is the difference between a pipe union and a pipe coupling?
What is the difference between a pipe union and coupling? It all comes down to the method of sealing. A union makes use of a seal ring between a pair of joints. The coupling, meanwhile , has either a socket or thread used to create that connection.
What is a Pipe Coupling?
A pipe coupling is essentially a short tube, also known as an outer joint. The coupling connects two pieces of piping together, retaining the integrity of both pipes. The good news is that pipe couplings can be used to join pipes that are either equal or different in size.
How long do pipe couplings last?
Given how easily they can mount and dismount, one may assume that they wear down more quickly. But when properly installed, pipe couplings can last years with little to no issue. Compare no hub couplings to flexible couplings.
What are pipe unions made of?
It depends on the situation and use of the pipe unions. The most common metals used are stainless steel, aluminum, brass, copper, cast iron, and bronze. ...
What is the good thing about a split pipe?
The good thing about these connections is that they allow these pipes to detach for future repair or replacement . Should one side of the pipe go bad, it can be split from the connection without causing a deformation in the pipes.
Why do flexible couplings rotate?
A flexible coupling, meanwhile, connects two shafts that are end-to-end in the same line. The reason is to transmit torque from one shaft to the other, which causes them to rotate in unison. The other is to compensate for the little bit of random movement and misalignment that can occur between the two shafts.
What is the difference between a coupling and a union?
But there is a difference between a coupling and a union in terms of black and galvanized pipe. A coupling is a solid fitting with female threads on the inside of both ends. It is used for joining two lengths of pipe together that are not locked in place and can be turned. A union is used when you are trying to join two pipes together ...
How is a union similar to a coupling?
A union is very similar to a coupling, except that it can be unscrewed into two separate pieces and then screwed back together when both separate ends are attached to the two pipe ends that need to be joined.
How to loosen a union?
Loosen the union by spinning the nut in the middle holding the two ends together.
Can you use a coupling to repair a black pipe?
If dealing with black pipe, make sure to check all your connects to ensure that there are no leaks. Using a coupling or a union to repair plumbing is fairly simple. But there is a difference between a coupling and a union in terms of black and galvanized pipe.
What is a pipe union?
Pipe Union is a type of fitting equipment designed in such a way to unite two pipes which can be detached without causing any deformation to the pipes. Any kind of small diameter piping connections requiring a positive seal and easy assembly as well as disassembly are made with the help of pipe union. In other words, the pipe unions can disjoint ...
What are the applications of pipe unions?
Applications of pipe unions: Pipe unions are used in various municipal and industrial applications like as follows: Fire protection. Process piping system. Water and wastewater etc. Advantages of pipe union: There are various advantages of pipe unions like: To provide a leak-proof disconnection point in any piping system.
What is a female threaded fitting?
A female threaded fitting has threads on the inside, while in the male-threaded fitting, the threads are on the outside. As the pairing ends of the union can be interchanged, these pipe fittings can be easily changed in a short span of time. With the joining of the female and male ends, the nuts are used to provide the necessary pressure ...
What happens when you pull stress on a pipe?
When severe pulling stress is applied onto the pipe union from the outside, the locking screw breaks and removes the two parts of the union, which in turn separates together with the pipes to which they are attached. Under normal conditions elastically stressed sealing objects ensure maintenance of watertightness between the union parts.
What are the two types of pipe unions?
Types of pipe unions: There are two basic types of pipe unions: Ground Joint Union : A ground joint union comprises of an angle that is cut into the union to make the two sections meet. It increases the surface area at the joint allowing seating properly.
Why are nuts used in a joint?
With the joining of the female and male ends, the nuts are used to provide the necessary pressure to seal the joint.
