What is a Pipe Union

Pipe Union

A pipe union is a secure and semi-permanent connection between two pipes. Most pipe unions consist of two pipes connected together via a third piece. All three are threaded to make a firm connection. While unions are similar to couplings, they are generally easier to take apart and allow pipes of different metals to come together safely. This joining method is common in household and commercial pipe systems.
At first glance, a pipe coupling and a pipe union seem very similar. They both connect two pipes together using a male and female threading system. The main difference between the systems comes from the actual method of joining. Two coupled pipes screw together directly, one inside the other. To take the pipes apart, every pipe that connects to the coupled pipe needs to turn. In a full pipe system, this would mean the entire system needs to come apart to remove one pipe.
With a pipe union, the two pipe ends don’t screw into one another—they each screw into a third piece. When one pipe needs to come apart from the other, the union piece simply screws onto one of the two pipes completely. If both ends of a pipe are attached using a union, the pipe may be removed on its own without unscrewing the other pipes in the system.

Materials used:

  • Stainless steel
  • Cast iron
  • Aluminum
  • Nickel
  • Copper
  • Brass
  • Bronze
  • Alloy
  • Plastic
  • Rubber etc.

Buyer’s guide

Important features that buyers should look for:

  • Type
  • Standard
  • Material
  • Size
  • Durability
  • Easy to install
  • Corrosion resistance

Three parts of pipe union:

  • A nut
  • A female end
  • A male end

With the joining of the female and male ends, the nuts are used to provide the necessary pressure to seal the joint.
The parts of the pipe union are normally locked together by at least one radial screw or nut with sized cross section. 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.

Types of pipe unions:
There are two basic types of pipe unions:

  • Ground Joint Union
  • Flange Union

The difference between the two is that the former consists of three pieces while the latter two pieces.

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.
  • Used for inserting metering and regulating devices into any plumbing application.
  • Can connect piping system to vessels.
  • Can join two pipes of different size together.
  • Can easily remove the join between two pipes.
  • Easy to install.
  • Economical.

Related News

العربيةБългарски简体中文繁體中文DanskNederlandsEnglishFrançaisDeutschBahasa IndonesiaItaliano日本語한국어LatinPortuguêsРусскийEspañolதமிழ்ไทยTürkçe