Frequently asked questions and their answers

Yes, either open or closed! Gate valves are service elements, NOT regulating devices. If the valve is not fully open or closed, this can lead to cavitation.

No. Hawle products are designed for medium temperatures between 0°C and 40°C. They cannot be used at temperatures outside this range.

Valves with a manual drive must be able to withstand at least 250 opening and closing operations according to the standard EN 1074. For valves with a motor drive, this figure is 2500 opening and closing operations.

At every high point, on long stretches of pipeline on an incline or decline, after pumps and in every position at risk of negative pressure.

Up to a main line size of DN 250, Hawle combined air release valves can be used without a chamber.

For service valves, the correct extension spindle is 3/4” to 2” and has a thread for ease of assembly in a rigid or telescopic design.

This is intentional. The distance bush deforms when the bolt is tightened, protecting the bare thread against corrosion.

In the System 2000, a support liner must be used with thin-walled PE pipes (≥ SDR 21) and pressure pipelines.
A support liner is also required for Synoflex connections with PE pipes ≥ SDR 17.

When drilling steel, ductile iron, fiber cement, PVC or PE pipes, we recommend drilling machine no. 5800. When drilling steel and ductile iron pipes with cement mortar cladding, we recommendation drilling machine no. 5805 with automatic feed.

The correct bolt must be chosen depending on the working pressure. See the technical ‘Chapter R’ in the Hawle water catalog for more information.

All Hawle hydrants have an independent drainage function and are therefore frost-proof. Drainage time: < 10 minutes. We recommend installing a ‘Sickerpipe’ drainage pipe for hydrants, which guarantees that the drainage function will always work correctly.

An automatic actuator can be fitted onto any E2 or E3 model. The actuator can be retrofitted up to the dimension 200, while larger dimensions can have the actuator installed in the production plant.

Air release valves are not maintenance-free fittings and must therefore be serviced at regular intervals depending on the water quality.

All internal threads on Hawle products are fitted with a corrosion protection ring to prevent corrosion and incrustation. This significantly increases the service life of a threaded connection.

End restraints secure and fix the fitting after its angle and length have been adjusted in order to prevent uncontrolled movements of the pipeline. In the case of fully extended Vario fittings, the end restraints also prevent axial overloading.