Watkins Powis have a comprehensive range of copper pipe fittings and press systems for your plumbing and heating needs. In this article we explore how Press Fittings seal Copper Pipe Joints.
How the Fitting Works
Press fittings consist of a copper or gunmetal sleeve which has an O-ring fitted into a groove within the sleeve. The pipe is pushed fully into the fitting and then a pressing tool with jaws of the correct size for the pipe diameter applied to the outside of the fitting. As the tool is tightened the fitting wall is forced inward to lock tightly around the pipe.
The O-Ring’s Role
EPDM rubber O-rings are fitted into a groove within the fitting. When the fitting is pressed around the pipe, the O-ring is squeezed into the space between the fitting and the pipe wall. Because the O-ring is squeezed evenly all the way around the joint, a tight seal is created. Suitable for both hot and cold water systems, the EPDM O-ring is also resistant to many common chemicals and is therefore ideal for use in central heating systems.
The Pressing Action Itself
The pressing tool is used to permanently form the pipe fitting. This will create a strong and watertight joint. There are a variety of jaws that can be used with the pressing tool, each being designed for specific pipe diameters. A useful reference for Copper Pipe Fittings is /watkinspowis.co.uk/products/copper-pipe-fittings-and-press-systems/.
Checking the Joint Afterwards
Look for an indicator window or a tab on the fitting that will show how much the fitting has been deformed when it has been pressed correctly. Check every joint before pressurizing the system. CIPHE approved methods for pipework jointing include details of how to complete a joint and how to test systems.
Common Mistakes to Avoid
The most frequent error with press fittings is not pushing the pipe far enough into the fitting before pressing. If the pipe is not deep enough in the fitting then the O-ring will not be able to form a seal properly. Make sure that the pipe is pushed all the way to the depth mark on the fitting before applying pressure. Also make sure that the cut end of the pipe is clean of dirt or swarf to stop it damaging the O-ring on entry.
All correctly pressed joints are permanent, strong and do not require the use of heat – ideal for small, intricate spaces and sensitive applications.