The next few paragraphs will go over the different ways we, as plumbers join pipe and fittings together. In each description we will list the different plumbing systems and which pipe joining methods apply and finally, the benefits and drawbacks of each.
Pipe Joining Methods
This is the process of joining pipe by melting a filler metal with a low melting point into a joint. When the filler metal cools it bonds the two pieces of metal together. In plumbing this technique is mostly done with copper piping. Soldering is used on all three plumbing systems water, waste and vent piping.
- 1The science behind soldering is very old and has literally stood the test of time.
- 2There is a learning curve but it isn't steep by any stretch so it's fairly easy to learn.
- 3The joints are fairly strong and water tight if done properly.
Brazing is very similar to soldered joints in that a filler metal with a melting point lower than the metal being joined is used to fill a joint between two base metals. Brazing is done primarily on water piping and more specifically on water services or larger diameter piping. It is a much more forgiving technique.
- 1As with soldering the technology is mature.
- 2The joints end up being stronger than the filler metal because of the way it reacts to the metal being brazed and are significantly stronger than a soldered joint.
Threaded pipe and fittings as they relate to galvanized water piping is a dying joining option. It will always be used for repairs or on specialized fittings i.e, flange fittings but it is not a preferred installation.
- 1We can't think of a single realistic benefit of installing galvanized pipe and fittings.
(Polypropylene piping) Although this technology has been around since the 60s it's had an extremely tough time gaining widespread use. Fusion technology is used when the plastics being joined can't be joined using cement. The basic procedure is as follows, a device/tool is used to heat the fitting and piping to a certain temperature melting a thin layer of the polypropylene plastic, the pipe is inserted into the fitting making sure the pipe hits home. After a certain time, usually around 15 to 20 seconds the pipe and fitting can no longer be manipulated and the fitting cures. The pipe and fittings actually fuse into one piece along the area of contact ensuring a positive seal.
- 120% material savings versus copper.
- 2There is a learning curve with the preparation and joining process however it is far more forgiving than it's copper counterpart. You will realize a labor savings once the technicians become proficient at the joining method.
- 3It is naturally acid resistant so neither hard water nor soft water has any affect.
- 4It has little expansion or contraction. No worries with freezing and thawing or pouring in a concrete deck.
- 5It is not an efficient conductor of hot or cold temperatures therefore there is very little condensation or sweating.
- 6Aqua Therm polypropylene gives you a 10 year (yes 10 years) insurance policy against product failure or incidental breakage. You can drop something on it and if it breaks it's covered.
- 7Some of the new materials being offered are green in the way the pipe and fittings are joined and in the material itself.
- 8There is zero electrolysis and a negligible amount of electrical conductivity.
A mechanical joint is any method joining piping or fittings by way of a coupling that uses compression of a rubber gasket to ensure a water tight seal. Two examples of mechanical joints are flanged pipe and fittings, grooved pipe with couplings or fittings that have a rubber gasket which sits inside the groove and the rubber is compressed filling the groove and sealing the joint.
- 1In theory the repairs on these applications are easier to perform.
- 2These are high pressure fittings so their tolerances are high. You can install very large diameter pipe and fittings.