How to connect the hdpe pipe with a crane

Without exception, all pipelines, whether plumbing or heating, are mounted with the installation of valves. The crane is necessary to disconnect a separate section of the pipeline from the main line.

There are many types of cranes, differing in their device and principle of operation. Many models are designed for certain pipes. In this article, we will look at the types of valves and fittings, learn how to connect the HDPE pipe to a crane and what types of valves are used when installing the pipeline.

Cranes for pipes PND

For pipes HDPE special cranes are used, characterized by ease of installation. The choice of model of the crane depends on the type of the substance through the pipeline, its diameter, location and method of installation. Some models are selected for pipeline design. The valve is installed at the junction of the pipe to adjust the flow, as well as its overlap. A ball valve is used in the plumbing system. Its use is possible in the gas industry. Ball valves have not only an external difference (for hot water valves are painted red), but also differ in the composition of the material from which it is made. If we consider the design of the crane, then we can distinguish three types: the entrance, the corner and multi-pass.

The design of cranes for polyethylene pipes is diverse, and depends on the drive mechanism:

• The design of a ball valve with manual control is installed on the pipeline with a small diameter pipes. It works by manually turning the handle, so it must always be freely accessible. Such taps are installed on domestic pipelines, for example, home plumbing.
• Well proven in the work of cranes, equipped with a gearbox. The operation of this mechanism ensures the rotation of the crane with the least effort. Thanks to the gearbox, the crane body has a compact size.
• On large pipelines with a pipe diameter above 150 mm, valves are installed not only mechanically but also with automatic actuators. Three types of mechanisms are used to control them: pneumatic, hydraulic or electric. The control of the crane mechanism is carried out from a long distance, or they are generally automated and operate from the installed sensors. For example, the presence on the automation of a temperature sensor allows you to adjust the position of the crane mechanism depending on the temperature, without human intervention.

Crane installation

The connection of the ball valve with the pipe PND performed by different methods. Let's look at them in order:

1. The simplest and most hermetic type of installation is obtained by butt welding. However, the connection of the pipe with the crane is obtained one-piece and, if necessary, its dismantling, the crane will have to throw away. Reapply it is no longer possible.
2. The flange connection is carried out by welding to the HDPE pipe sleeve with cap metal flanges. The union flange is connected to the flange of the crane by a bolt joint, and a rubber gasket is placed between them. The flange valve is designed for two turning positions, and its body is cast from cast iron or stainless steel. Some models have a collapsible case, consisting of two parts. Such collapsible models of cranes can be repaired. The crane is installed on HDPE pipes of large diameter.
3. In gas pipelines, heating systems and water pipes with a pipe diameter of up to 45 mm, valves with a coupling connection are used. Such a connection is also considered simple and easy to use.
4. Cranes with reusable fittings are mounted with nuts and nipples. For the seal, install a gasket at the junction.
5. The combined method of installation of the crane includes a flange connection and butt welding.

Welding HDPE Pipe with Crane

The most common method of joining HDPE pipe with a ball valve is butt welding. It is performed by a special installation in which both edges of the welded blanks are fixed. The surface being welded is cleaned from dirt and degreased. The heating element heats the polyethylene edges of the pipe and tap to a viscous state, and by the mechanism of the apparatus they are squeezed together. The welded joint is allowed to cool. A properly welded joint should have an even seam of the same height.

Disadvantages of cranes for HDPE pipes

The main disadvantage is the limited diameter of the model. With the increase in the diameter of the pipe, it is very difficult to find a crane of the required size. Plastic ball valves have a higher cost than their counterparts, but their quality of work justifies its cost.

Tip! With frequent use of the valve with incomplete closure, for example, for adjustment, the locking ball is deformed and depressurization occurs.

But, despite these shortcomings, ball valves for HDPE pipes create convenient conditions for operating the pipeline. And the correct installation will ensure its reliable connection with the pipe.

Video

In this video you can see how to connect the HDPE pipes using couplings, bends, tees, as well as how to connect the pipe to the ball valve or make a flange connection with a metal valve:

This is an animated video about a saddle for tapping into the HDPE pipe under pressure: