When Are Telescopic Seals (Teleskopmanschetter) Used?

Below is a clear and complete explanation of when telescopic seals are used, what they do, and in which types of wells and installations they are needed.

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🟩 What Is a Telescopic Seal?

A telescopic seal is a flexible rubber gasket installed around a telescopic riser/neck on a well.
It seals the gap between:

• the well chamber (plastic or concrete)

• the telescopic riser (adjustable neck)

It follows the movement of the riser and prevents soil, surface water, and odors from entering.

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🟦 When Are Telescopic Seals Used?

Telescopic seals are used whenever an adjustable riser (telescopic section) is installed on a well.
Here are the most common situations:

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1️⃣ When the well cover height needs adjustment

Any time you use a telescopic riser, a telescopic seal is required to:

• create a watertight seal

• keep the riser centered

• prevent soil from falling into the well

• prevent infiltration and leakage

👉 Standard on plastic stormwater, drainage, and wastewater wells.

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2️⃣ Where the ground moves (settling, frost heave)

The seal allows the riser to move without:

• cracking the well

• damaging pipe connections

• misaligning the cover

👉 Ideal for residential areas where the ground often shifts.

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3️⃣ When the ground level is changed (paving, asphalt, gravel)

During:

• stone paving

• asphalt resurfacing

• raising ground levels

• cover height adjustment

…the riser can be moved up or down, and the seal maintains a tight fit.

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4️⃣ When the well must be completely sealed

To prevent:

• root intrusion

• surface water infiltration

• odor leakage

• dirt entering drainage or pump systems

👉 Essential in LTA/LPS pump stations.

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5️⃣ When the riser is smaller than the well opening

The telescopic seal acts as a transition and sealing interface.

Examples:

• Well Ø400 → riser Ø315

• Well Ø600 → riser Ø400

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🟥 Where Are Telescopic Seals Used?

✔ Stormwater wells (plastic)

Nearly always required.

✔ Drainage wells

Protects the drainage system from soil and sand.

✔ Wastewater / inspection wells

Used when adjusting the cover height.

✔ LTA/LPS pump stations

Prevents earth, water, and pressure from entering the pump chamber.

✔ Water meter wells

Keeps the well dry and insulated.