Assembling of PVC products
The making of a good cement connection takes more attention than generally is considered. Never the less in most cases a cement connection, which is not optimal, will give a satisfying result for a load lower or normal to the working pressure. However a not optimal cement connection can lead to a decreasing of the working pressure which the tube and fitting can withstand!
When the cement connection is exposed to extreme circumstances (like in test-installations) than it is a must to have an optimal cement connection.
Cement instruction:
Requirements:
· Sanding-paper with structure ¡Ü 80
· Pencil
· Cleaner for PVC-U (like "Tangit Cleaner")
· Polish paper
· Chamfering tool
· Removable tape
· Brush in the right size
· PVC solvent cement attuned to the demanded pressure rating (like "Tangit Klebstoff f¨¹r PVC")
· Stirring spoon
· Cover for pot of solvent cement
Preparation:
· The pipe must be cut off at right angles
· Chamfer the outside edges at approximately 15º
· Mark the jointing length on the pipe
· Make a band on the edge of the jointing length with removable tape
· Check if the cement runs evenly from the stirring spoon. If this is not the case then you must remove the top layer of the cement. Stir the cement properly. PAY ATTENTION: The cement must not be diluted!
· Cover the pot of cement when you are not cementing.
Cleaning:
· Clean the surfaces that are gone be cemented with Cleaner for PVC-U and polish paper. The Cleaner has to be applied sufficiently and with powerful movements on to the surface.
· Due to the use of Cleaner the PVC surface becomes weak. To check if the surface has been cleaned properly you can run your nail over the surface just after the evaporation of the Cleaner. When properly cleaned this will produce a chip of PVC.
· Use the cleaning paper only once!
Cementing:
· The cementing has to be done with a brush in an axial direction (the pressure, which is applied on to the brush, is better then cementing in radial direction).
· Use a brush as subscribed:
|
Nominal diameter |
Brush type / Brush dimensions |
|
¡Ü 32 mm |
Round brush 8 mm |
|
40 - 63 mm |
Flat brush 1" |
|
75 - 160 mm |
Flat brush 2" |
|
225 - 280 mm |
Flat brush 2½" |
|
315 mm |
Flat brush ¡Ý 3" |
· Apply a layer of approximately 0.5-mm of solvent cement on to the fitting. Apply this with a fair amount of pressure on to the brush.
· Place the fittings in a way that the cement will not be polluted.
· Apply the cement in a layer of approximately 1-mm and again with fair amount of pressure on to the pipe.
Note: From diam. 90 mm you have to cement the pipe and the fitting at the same time.
· PVC solvent cement has an "open time" of approximately 4 minutes at 23ºC. Within this time pipe and fitting has to be fitted.
· Slide the pipe and fitting in a linear movement in to each other. During this procedure the pipe and fitting must not be rotated!
Note: From diam. 160 mm we advise you to use an auxiliary mounting tool to fit the pipe and fitting.
· Remove the excess of cement with the polish paper.
· Remove the tape.
Drying time/ Curing time:
· At 23ºC PVC solvent cement has a drying time of approximately 4 minutes. No motion between pipe and fitting may happen within this time. When the temperature is below 10ºC the drying time will be approximately 15 minutes.
· The cemented pipe can be digging in the ground after 10 to 12 ours.
· The curing time of the cemented fittings depends on the appearing pressure and temperature. Take account of the next curing times:
|
Pressure |
Temperature |
Curing time |
|
Working pressure |
¡Ü 23ºC |
1 our per 1 bar working pressure |
|
1.5 x Pn |
¡Ü 23ºC |
24 ours |
|
3,2 x Pn |
20ºC |
20 days |
|
2 x Pn |
40ºC |
30 days |
How to cement bigger size fittings:
The "open time" of PVC solvent cement is approximately minutes.
In favour of big fittings: Pour the cement in the fitting and on to the pipe. Divide the cement radial and the spread evenly in axial direction. The pipe and fitting have to be cemented at the same time. You have two minutes in total for this action. If necessary you can use a solvent cement with a longer "open time (for example Griffon UNI 100-GT)
May the solvent cement be diluted?
The solvent cement may in no way be diluted with PVC-Cleaner. In between the cementing the brush must be placed in the pot of cement and this must be covered in total. The brush can be cleaned in PVC-Cleaner. Before using this cleaned brush, the brush must be dried.
Which fit must the fitting and pipe have?
The fit tolerance of pipe and fitting is based upon a transition fit. To make sure that the cement will not be scraped away the pipe must be chamfered and the pipe and fitting must be slide with a linear movement in to each other.
The PVC solvent cement is suitable for a gap width from -0.2 up to +0.6 mm (Tangit).
Does the surfaces need to be sanded before cementing?
It is not necessary to sand the pipe and fitting before cleaning. When you chose to sand, take sanding-paper with structure ¡Ü 80. Cleaning with PVC-Cleaner will normally be enough.
Why use PVC Cleaner?
Due to the PVC-Cleaner the surface of the pipe and fitting will solute a bit. This allows the cement, which is based on PVC, to penetrate better into the pipe and fitting. The molecule chains will be better strangled which gives a better cementing joint.
To check if the surface has been cleaned properly you can run your nail over the surface just after the evaporation of the Cleaner. When properly cleaned this will produce a chip of PVC.
Catalogue
Lissenveld 1
4941 VK Raamsdonksveer
The Netherlands
Phone: (+31) 162 516000
Fax: (+31) 162 521417
E-mail: info@vdl-fittings.com
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