Flange bolting is a vital part of plumbing. It is the process by which two pipes are connected via a flange and a bolt system often employing either Belleville or spring washers. Although flange bolting is most often employed in the construction industry, if you are building on your home or simply fixing a piping issue, the technique of flange bolting is essential to know and understand.
What is Flange Bolting?
A flange is a metal disk which protrudes from around the edge of a pipe opening. A flange has many holes designed for bolts organized in order around it. When two pipes must be connected, two flange-ended pipes are placed end to end; the flange holes are lined up and bolts are used to hold them in place. The problem therein is that a large amount of force must be consistently applied to waterproof the gap between the two pipes.
This is the only effective method of laying long stretches of pipe under roads, through factories and in homes. Transporting an entire pipe for a sewer or plumbing unit would be impractical, and pipes have to be adapted to geographical concerns such as the twists and turns in walls or large boulders in the ground. As such, pipes are manufactured in multiple shapes and lengths then assembled on-location with flange bolting techniques.
Coil Springs and Belleville Springs:
The massive pressure applied to a flange bolt must be prepared for; otherwise, weather changes, wear and tear or even a quick surge of water may cause leaking, or rupture the connection altogether. As such, the bolts are manufactured with built-in washers. This, however, is often not enough and spring fasteners have been developed to assist in taking the strain. A coil-spring fastener is, at its simplest, a spring placed on either side of the flange bolt to absorb the shock of increased water flow or weather provoked swelling and shrinking of a metal pipe.
The disadvantage of a coil-spring fastener is that, when under pressure, it heats up and may warp, therefore losing its tension, and can lead to leaking. To combat this, conical washers (or Belleville springs) have been developed. When a conical washer is fastened wide edge to wide edge with another conical washer it takes on the properties of a spring, the pocket of air created allows it to buckle and bend and its three-hundred and sixty degree contact means that it buckles in an even fashion. Multiple pairs of washers placed end to end can be used for higher pressure connections. Although most often used in heavy duty industries, Belleville springs have gained popularity with home owners due to their durability.
How Can Flange Bolting Help You?
Often, when building extensions on your house or when fixing a piping issue, you will find yourself required to attach two lengths of pipe together. Flange bolting is the mechanism by which this is achieved. If you understand flange bolting, then it is within your power to make judgment calls as to the type of spring, bolt and washer you require to make sure there are no leaks or that the leaking will not occur again.
Good luck to you in your home improvement.