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Questions about Drilling Saddles
Choose a question:
Are the drill diameters for PVC pipes limited?
What is the difference between the A11N and TERRA M1 drilling saddle (for steel pipes) and the A52K and TERRA K3 (for PVC pipes)?
All of the drilling saddles are comparable in terms of their area of application. The TERRA programme is the latest range of next generation products and has an integrated auxiliary ball shutoff. The A11N and A52K's drilling saddle's auxiliary shutoff must be created with a laterally connected eccentric auxiliary valve. This auxiliary valve must be fitted and removed before and after each drilling.
Does the coating of a cement-mortar coated pipe have to be removed before drilling? What is the procedure for PE-coated pipes?
This is explained in detail in DVGW Guideline W333 Section 9.2.2:
Cast-iron pipes that are coated with cement-mortar according to DIN 30672-2 have sufficient adherence and smoothness, as well as low mortar porosity. The cement-mortar coating should not be removed in this case.
The cement-mortar coating that is applied to PE coatings, however, must be removed around the tapping valve because it does not seal on the PE surface.
The cement-mortar coating should not be removed from PE pipes that are coated according to DIN 30674-1 for corrosion protection reasons, providing adherence is good
Are the drill diameters for PVC pipes limited?
Yes. As always, the maximum drill diameters specified in DIN 19532 in Section 6.4 must be observed.
PVC pipes up to DN 100 may only be drilled with a maximum drill diameter of 27 mm and pipes up to DN 125 with a maximum drill diameter of 33 mm. From DN 150 onwards, VAG drilling saddles with a maximum drill diameter of 38 mm can be selected.
Does the PE-welding technique always have to be used when drilling PE pipes (TERRA K2, TERRA K4 or TERRA K12) or is it possible to use drilling saddles for PVC pipes (moulded strap clamp) such as TERRA K1 or TERRA K3 and for PE-L?
VAG's TERRA K1 (self-drilling system) and TERRA K3 (for drilling with a drilling tool) drilling saddles can also be used for PE pipes (SDR 11) up to and including DN 150.
Can VAG's brass PE stub fittings be directly connected to the valve without using hemp or seal strip?
Yes! VAG's PE stub fittings have an integrated O-ring that seals the drilling saddle. The PE pipe piece can be connected to the PE house connection pipe by a spigot-socket connection, or the short piece of pipe can be removed and the pipe tightly connected to the stub fitting.