Assembly
Assembly
sockets. The pipe must be inserted into the expansion socket up to the temperature indication point for the then prevailing ambient temperature (measure and mark on the pipe). - The following maximum lengths apply to pipe sections between 2 expansion sockets: "cold" pipework 13.2 metre; "warm" pipework 6.6 metres and "hot" pipework 4.4 to 5 metres (see also flexible installa- tion with expansion sockets 7.2.1).
Welding procedure A user manual describing the welding procedure should accompany every
- The pipe end must be free of burrs. - If a spigot end is very dirty it must first be cleaned with HDPE cleaner. If this is not done the dirt will be ground into the pipe when it is abraded later. - A layer must be removed from the spigot end. This is always required!! HDPE oxidises in air and in light. The oxidised layer must be removed to achieve an optimal weld. The oxidi- sed layer can easily be seen after extended storage in the open air. Extra care will then be required. The outer layer is best removed by abrading with clean emery cloth, grit 40. Remove the abraded particles. The following points are also significant: - Electro-weld sleeves have a short insertion depth, so that a pipe which is not cut square will weld poorly and provides a risk of fire. - Check the fit between sleeve and spigot end. If this is oval refer to "Oval Pipe ends" (8.1.4). - The pipe and fitting must not move during welding and cooling. If necessary fix with clamps. If the pipe or fitting sags or creeps the welding threads in the sleeve may sag inward. This may cause a fire. - With large installations a powerful stream of air may flow through the pipework which can act as a flue. This may cause appreciable cooling to the interior. The pipework should therefore be sealed with a protective cap. - The exterior of the electro-weld socket will become warm only after welding has commenced. The joint may only be loaded after the socket has cooled. - The ends of pipes and fittings must be bone dry. If necessary pre-heat to prevent condensation.
of pipe ends may call for modified processing.
Ambient temperature
Table showing insertion depths for pipe of length 5000 mm
ø63
ø75
ø90
ø110
ø125 ø160 ø200 ø250 ø315
Insertion depth in mm
-10°C
60 60 65 65 75 75 85 85
65 70 75 80 85 90
75 90 100 115 135 85 100 110 125 145 95 110 120 135 155
item of welding equipment. - First connect to the power.
Rubber seals Two types of rubber seal are in use with HDPE waste systems. 1 With a round O-ring: - The O-ring housing and the ring itself must be clean. - The HDPE pipe must be cut square, bevelled off at around 30° and deburred. - Introduce the components to one another, up to the stop. 2 Sealing sleeve connection: - The sleeve and the chamber behind it must be clean. - Apply Wavin lubricant to the sleeve. - Insert the deburred, square cut and bevelled pipe. Expansion sockets Unlike the twin sockets used with PVC, expansion sockets in HDPE are in a single piece into which the pipe is inserted. A rubber sleeve is used as a seal. - Install expansion socket at previously determined locations and use brackets as for a fixed point. - With the socket end facing upwards in vertical pipework. - Attach the HDPE pipe firmly to the spigot end of the expansion socket (using a welded joint). - Align the expansion socket and pipework correctly at both ends. Fit an extra support bracket if required. The pipe end to be inserted must be correctly bevelled (min. 4 mm, 15°). - Apply Wavin lubricant to the rubber ring and the end of the spigot. - Where a stack is to be enclosed in a duct, protect the joint from mate- rials like mortar that might fall in. - Temperature indications appear on the outside of HDPE expansion
0°C
+10°C +20°C
- The "voltage" indicator lamp will illuminate. If the lamp flashes check voltage and connections. - Attach the connector cables to the electro-weld socket. Note: for safety reasons these cables must not be extended. - The "connection" indicator lamp will illuminate. - Press start button. The welding indicator lamp will illuminate. Once welding time is complete this lamp automatically extinguishes and the current supply switches off. - Check the weld indicators. They should have emerged by around 2 mm. Note 1: If the welding indicator lamp
95 100 105 120 130 145 165
Illus. 8.1 Insertion depth for HDPE expansion sockets with "hot pipework" for a range of ambient temperatures.
Illustration 8.1 may also be used to deter- mine the insertion depth.
9. Situations during construction
Fouling, damage and movement of the installed waste removal system must be avoided during construction.
Pressure test pipework before pouring concrete. Prevent grit from roofs entering waste pipework. This can be extremely difficult to flush out and can give rise to problems especially with rubber seals. Lead rainwater out of the building as quickly as possible (illustration 9.1).
flashes the welding process has been interrupted for one
Possible measures include:
Closing off pipework with protective caps. Use caps that fit over the pipe wherever possible so that they are not accidentally left in place. When using caps that fit within pipes, this should be clearly indicated. Seal off spigot ends that are still to be connected (by insertion, welding or cement). Expansion socket sleeves in vertical pipework should be protected from materials such as mortar that might get into the sleeve. Protect around 20 mm of pipe ends emerging vertically from concrete floors by sealing with plastic foam or similar prior to pouring concrete. This often prevents damage when the floor is worked on later. Ensure adequate anchoring to prevent flotation or bending of pipes during concrete pouring. Check direction and height of pipework before ceilings or ducts are installed.
reason or another. Identify and rectify the cause, allow the joint to cool completely (1 hour) and repeat the entire procedure. Note 2: The welding process may
only be interrupted by switching off the supply.
If the use of an isolating transformer is required for safety reasons, say in a damp area, then this may be done without problems. Extensive testing has shown that this does not affect the weld quality.
Use of non-standard pipe Electro-weld sockets are designed for use with HDPE waste pipes from KOMO series I and II (see table in Illustration 7.14). Pipes with thicker walls may also be welded using the electro-weld socket. Liaison with the supplier would then be recommended, since varying tolerances and greater rigidity
34
35
Illus. 9.1 Temporary situation during construction.
Made with FlippingBook Annual report