G/C-Open (Open Disposable / Single-use packer)

Open low-pressure packers with C/G check-valve (tip) for injection pressures up to approx. 65 Bar (depending on packer dimensions, possible injection pressure decreases with increased diameter). 

G/C-Open packer is equipped with 3 or 5 locking washers. These lock washers are sized to withstand the maximum specified injection pressure after the injection pipe is dismantled. However, consideration of the packer's friction against the rock must be observed when removing injection pipes.

Suitable injection tubes are "Mechanical Low Pressure Tubes 1/2" or "Manual 1/2" Tubes"

Notably, the so-called G/C check-valve (tip) requires some back pressure to seal after grouting. At very low injection pressures, a GX model of packer may be preferred.

The table below shows: GMA's part number, GMA's model designation, What drillhole diameter the packer is intended for, What diameter the packer has before tensioning, What work span (sealing aperture) the packer has, What connection it is on the thread  on the packer tube and tube dimension on ditto, Which approximately tightening torque required and approximate Maximum injection pressure*, #.

If more information is desired, we refer to the Technical data sheet (TDS) which is available as a PDF file to read/download.

* NOTE: Consideration must be given to rock type and hole direction to finalize maximum injection pressure. The table only shows what the packer itself can handle.

# Packer over diameter 70mm can be equipped with an extra HD lock washer (high pressure washer) if requested by the customer. However, doing that requires HD type injection tubing and should not be confound (mixed up) with HD packers (it is still a Low Pressure Packer).

Export model of Open High-pressure packers with C-check-valve (tip) for injection pressure up to approx. 100 Bar for hole sizes between 48mm up to 66mm. CS-Open packers for hole diameters greater than 66mm are not, according to GMA's definition, intended for high injection pressures, see table below.

CS-Open High-pressure packers are equipped with 5 std. lock washers and an extra high-pressure washer (HD washer). These lock washers are sized to withstand the maximum specified injection pressure after the injection pipe is dismantled. In addition to internal development and testing of high-pressure packers, tests have also been made of GMA's HD packers at 3rd party (DNV Norway).

Notably, when storing CS-Open packs for more than 12 months, additional back pressure may be required for the non-return valve to close tightly.

GMA's high-pressure packers require adapted injection pipes, so-called "HD-Injection pipes for mechanical mounting" which are adapted not to damage the HD lock washer during tightening and equipped with a rotating safety hook and ball valve for high pressures.

The table below shows: GMA's part number, GMA's model designation, What drillhole diameter the packer is intended for, What diameter the packer has before tensioning, What work span (sealing aperture) the packer has, What connection it is on the thread  on the packer tube and tube dimension on ditto, Which approximately tightening torque required and approximate Maximum injection pressure*, #.

If more information is desired, we refer to the Technical data sheet (TDS) which is available as a PDF file to read/download.

* NOTE: Consideration must be given to rock type and hole direction to finalize maximum injection pressure. The table only shows what the packer itself can handle. In cases where there is bad rock, high pressure packers with mechanical locking are also available, see section "Special packers high pressure flow"

# CS- packers are supplied for drill holes between 48mm up to 66mm. This is based on the size of the HD washer and performed tests. In the event that injection tubes are not removed immediately after injection, other injection pressures and larger diameters can be used if necessary, but then do not fall within GMA's definition for an HD packer.