Hydraulische afsluiter enkel en dubbel

Available dimensions: Ø 28, Ø30, Ø42, Ø56, Ø170

Each single packer from Ø 28mm to Ø 170mm can easily be transformed into a double packer assembly by adding a specific element: the central element CE. Just unscrew the sliding end from the single packer and replace it with the CE element. Complete the installation by screwing a standard inflatable element S (sleeve) and a plug PL on the lower part of the packer.

The perforated CE central element from Ø 56mm to Ø 170mm consists of a compact and perforated tube, with a diameter identical to the whole packer assembly. This design makes the double packer ZI extremely robust and the external flush O.D. is particularly well adapted to micropiles grouting and water pressure tests.

With Ø 28,30 and 42mm packers, the narrow space between the two packer elements does not allow to use the same tubular design.

Here, the CE element consists of 4 pipes, two of which are used for inflation of the lower packer.

As standard, the central element can be extended except the 42mm one which is on request only.

A special characteristic of these packers is that the injection zone (IZ) length remains constant after inflation.

Use recommandations.

The ZI double packers Ø 28, 30 and 42 mm are specially designed for "tubes a manchettes" grouting use; the injection zone length (IZ) remains constant regardless of the diameter of the "tube a manchettes".

The bottom element of the packer is flexible making it easy to introduce into and retrieve from the "tube a manchettes" .

The choice of which packer to use depends on the "tube a manchettes" inner diameter. Please refer to the selection chart shown on the left.

EK Extension Kit ( s6-17Omm)

For the double packers Ø 56 to Ø 170mm, some applications may require a longer injection zone than the standard one determined by the CE central element length.

In this case, an EK extension kit is available to facilitate extension between the two inflatable elements.

The 3 elements of the EK kit are:

• The JF junction end
• The ER extension pipe
• The FE fixed end

These elements are easily screwed together to form a complete assembly.

Thanks to their modular design, Geopro packers can be adapted in a flexible and economical way to suit the various demands of each job, wherever the worksite.

For some hydrological applications at low or medium pressure, Geopro proposes a specific double packer, the "TZ" which is available from 56 up to 170 mm diameters.

In this configuration, the two packers fixed ends are put into the test zone "IZ". In this way, after inflation, the "IZ" length stays constant.

Basic components of a double packer "TZ" are:

• Two standard packers, one of which is mounted on top with the specific sliding end SSE which has two inflation ports.
• In the center, an extensible perforated tube CPP closed at the bottom. These tubes CPP are standard pipes with BSP threads.
• An inflation line CI into the test zone with reinforced inflation hose mounted with swaged couplings.
• Others configurations (for the positioning of the sliding and fixed ends) are available on request.

Different parameters determine the use of inflatable packers.

These must be clearly identified in order to define the most suitable procedure for the planned application in each case.

One of these parameters is the diameter of the bore-hole: the greater the diameter of the bore-hole, the smaller the maximum operating pressure for the same packer.

Another parameter is the depth of use and the water level in the bore-hole.

As well as this, it is advisable to check the static water level (SWL) before and after placing the packer into the bore-hole.

The choice of inflating fluid (water or gas) depends mainly on the difference between the depth of use and the hydrostatic level in the bore-hole (SWL).

1) when inflating with gas, the pressure applied from the surface (pressure gauge) must correspond to the desired inflation pressure, to which shall be added the pressure from the water-column ( one bar per 10 metres of water-column) on the packer.

For example, an packer is placed 100 m below the water level (SWL) and must be effectively inflated to 20 bar. In this case, gauge pressure must be 30 bar: 100 metres of water-column is approximately 10 bar plus the 20 bar of pressure for inflating the packer.

2) Water inflation. In this case, the pressure to be applied from the surface (pressure gauge) must correspond to the desired inflation pressure, which will be decreased by the pressure from the height of the water (A) contained in the inflation hose between the surface and the static water level (SWL).

Using the same example for a height A of 5O metres, the pressure read on the surface pressure gauge must be 15 bar, i.e. 20 bar less 5 bar (50 metres).

Water inflation also has several other advantages such as its low cost, availability and ease of transport.

N.B.Sometimes the pressure resulting from the height of the water A in the inflation hose is sufficiently high to make it impossible to deflate the packer (see expansion curves). Geopro has a deflation device which makes it possible to use water as the inflation fluid in most applications.