Wellpoint Dewatering

Sub ground Dewatering or Wellpointing as it is often called is a method of controlling or lowering the level of sub ground water within an aquifer.

When Contractors are faced with having to excavate below the existing sub ground water level into the auquifer the simplest and most cost effective method would be to deploy a Wellpoint system.

In modern practice Wellpointing is considered most suitable for relatively shallow excavations up to 6.5 metres deep in stratified soils, especially where the water table must be lowered very near to an underlying bed of clay or impermeable rock.

Wellpoint systems typically consist of the following

Small diameter pipe known as (riser pipe) fitted with a fine filter (wellpoint filter) this filter prevents fines entering into the system and being removed from the ground in the pumped water.

This riser pipe would be connected above ground to a flexible pipe via a control valve to the header pipe which in turn connects to the suction connection of  a specialist vacuum wellpoint pump.

The discharge side of the wellpoint pump is connected via the discharge pipe to a settlement tank which further collects any fines and then on through the discharge pipe to the discharge point.

Once the pump is switched on it creates vacuum and pulls water out of the ground thus lowering the sub ground water level and pumps the water to the designated discharge point.

The Wellpoints are jetted into the ground using a high pressure water pump (jetting pump) delivering water down a steel tube (jetting tube) to a maximum working depth of 6.5 metres.

The Wellpoint filter and riser pipe are installed along with a granular filter pack to aid drainage and then connected to the the system.

Wellpoint systems are very effective in a wide range of soils from fine silty sand to corse gravels, single stage Wellpoint systems are used to a maximum depth of 6.5 metres, for deeper excavations twin stage Wellpoint systems can be deployed.

The equipment used falls into two categories the above ground equipment which can be re used and is usually hired or rented and the equipment below ground (risers and filters) which are normally regarded as disposable items and as such are sold to the customer.

The pumps that are required for Wellpointing duties are critical to the efficiency of the system and must have excellent air handling and air separation capabilities as such they are regarded as specialised units.

Performance Pump & Equipment are able to supply such Wellpointing pumps for hire throughout the UK and indeed are the preferred supplier of such units to most of the Major Wellpointing Contractors in the UK.

Performance Pump & Equipment can supply the full range of equipment for general Wellpointing operations, equipment such as jetting pumps, fire hose, jetting tubes, header pipes and valves, discharge pipes, settlement tanks, riser pipes and Wellpoint filters.

It is the aim of Performance Pump & Equipment to support its customers with a complete range of pumping equipment and associated services, please contact Performance Pump & Equipment for solutions to your pumping requirements.

 

Performance Pump & Equipment - "We Perform"

 

Back to home page