PVC Pipe Technical Information

The subtle difference between the two jointing methods with any type of pvc pressure pipe (eg pvc pipe, pipe coupling and pipe connectors) is that one creates a permanent joint that cannot be disassembled and the other either a semi-permanent or temporary joint which can be disassembled.

The first and most popular method is by solvent welding, or more commonly referred to as gluing, utilising solvent ‘cement’ or ‘glue’. This method requires a low skill capability.

The second method utilises a simple threaded connection system where interchangeable male threaded fittings (threaded on the outside) are connected or are screwed into female threaded fittings (threaded on the inside) this method does not require any skill capability.

Both methods are relatively quick and uncomplicated providing the correct preparatory work is carried out before any joint is attempted.

Below we have listed the key elements to the joint preparation required to ensure a leak free connection, let’s take a quick look at both methods…

 

The Solvent Cement/Glue Jointing System

PVC ‘solvent cement’ or ‘glue’ are commonly used references that mean the same thing. This in essence is the chemical mix that when applied to the mating surfaces of the PVC pipe, fitting or valve connection, welds them both together by chemical reaction creating what is technically known as an ‘homogenous bond’ i.e. the two separate surfaces are now chemically fused to become one.

You can see a range of PVC cement products on our accessories page.

 

Top Tips for PVC Solvent Welding with PVC Pressure Pipe

* We highly recommend that you double check all of the actual measurements of the physical structure to be assembled against any drawings, sketches or samples before cementing anything together. If possible test your structure first with a dry-fit to ensure everything fixes together nicely and is dimensionally correct.
* To ensure an effective joint, make sure the area is free from all dust and debris and is dry before you apply your cement.
* Prepare and clean your materials before cementing them using our MEK Cleaner, available in our accessories section. Always check the tin of solvent cement for details of the recommended curing times per system size that is being assembled and adhere to these instructions. Also ensure that the correct PPE (Personal Protective Equipment) is used during assembly.
* Always ensure any empty tins, used glue brushes and PPE are disposed of in the correct manner.

 

The Threaded Fittings Jointing System

This is the simplest method of joining pvc pressure pipework system components together which requires little or no skill, special equipment or tools.

However, like other jointing systems the correct checks and preparation will ensure the best joints. Some simple checks need to be made before attempting any connection.

You can see a range of PVC threaded fittings on the Imperial threaded section of our website.

 

Top Tips for PVC Threaded Jointing

* First and foremost is to ensure that the thread types e.g. BS, NPT etc are the same for both the mating male and female fittings.

* Threaded fittings can be supplied in both TAPER and PARALLEL type threads. The threaded male and female fittings supplied by eeziflo generally both have PARALLEL threads. This usually means that the connections are easy to make, feeling loose on both assembly and disassembly. The fittings generally mate 100%. If TAPER threaded fittings are used, the connections can feel tighter on assembly and the fittings generally do not mate 100%.     

* Check that the threaded connection sizes are compatible.

* When creating threaded connections in a plastic system always ensure that PTFE thread seal tape is used on the threads and not jointing pastes which can attack the plastic base materials.

* A hand tight connection is generally considered sufficient to create a leak free joint. There is generally no requirement to use a spanner or wrench on a plastic threaded joint. Under no circumstances should plastic pressure pipe fittings and pvc threaded fittings be joined to metal threaded fittings.

 

Solvent Weld or Threaded Connection?

If you require a fixed permanent connection with no maintenance then we would recommend solvent weld. Systems joined by solvent welding are generally available in a much larger range of sizes.

If you require a semi-permanent connection which may require disassembling at some point, then we would recommend a threaded connection. Systems joined by threading are only available in a limited range of sizes.

It is important to know the difference between pvc metric and pvc imperial fittings before you begin specifying your project. Visit our PVC pipe Technical Advice Page for more information or give us a call on 0113 2359970 to discuss your exact requirements in detail.