Section Navigation

STOPAQ® Products » Application: Coating of Underground Flanges

Underground flanges can be rapidly, effectively and simply protected against corrosion with the STOPAQ® System.

Safety and technical data sheets for the material to be applied

Preparations

  1. The pipe-piece to be coated must be excavated sufficiently so that it can be handled on all sides.
  2. Excavate 0.3m under the lowest pipe part.
  3. The working area must be kept dry during application.
  4. Check regularly whether the pipe stays above dew point by means of a dew point gauge.
  5. Drain (if necessary).
  6. Keep free from rain, but provide sufficient ventilation with regard to dew point.

Base surface quality

The part of the pipe where the coating all around has to be removed, is the length of the flange rim + 150mm (L1 + 150mm).

Clean the space between the flanges with compressed air and dry.

The old damaged coating must be removed all around from the flange faces and the pipe. Clean as thoroughly as possible. The surface to be coated must be clean and dry and free of loose parts. This can be achieved by brushing to St 2, and when persistently dirty it must be grit-blasted to Sa 2.5.

To prevent damage to the seal during grit-blasting, apply a temporary rubber string between the flange faces.

At the point of connection to the bitumen/PE, this must be bevelled under an angle of 30°. The bitumen between the two connecting spots must be removed entirely. The bitumen coating, where the final layer is applied, should be dry-burned carefully with a non-soothing burner. The base surface must be dry and clean. Should irregularities be found on the pipe around the repair spot, then management must be consulted.

If the coating consists of asbestos bitumen, the applicable regulations for removal must be followed.

Application of STOPAQ® Wrappingband CZ (H) on the pipe part

If applied properly STOPAQ® Wrappingband CZ (H) provides long-lasting corrosion protection to the adjacent pipe. STOPAQ® Wrappingband CZ(H) must be at a temperature between 15°C and 25°C, for optimal application of the product.

If there are any sharp pieces on the weld and/or redundant weld pieces, STOPAQ B.V. recommend to grinding it and/or applying extra tape over the welds.

The first wrapping must be applied tightly to the existing coating on the brushed base surface. Wrap with minimum 10mm overlap tightly to the flange face. An extra wrapping is then applied on the transition of the existing coating, and in such a way that it is overlapped by 5cm.

Application of STOPAQ® FN 4100 on the flanges

To optimally apply the STOPAQ® FN 4100 this must have a temperature between 15°C and 25°C. Fill up spaces between the flange faces with STOPAQ® FN 4100 as good as possible. Remove redundant STOPAQ® FN 4100 with a putty knife to a smooth whole. Apply the STOPAQ® FN 4100 under an angle of approx. 45° on the outside of the flange and pipe. Ensure the bolt ends are fully covered. The bolts and nuts are under a layer of STOPAQ® FN 4100. Spread the STOPAQ® FN 4100 bulb-shaped and clean the outer flange rims as good as possible.

Application STOPAQ® Wrappingband CZ (H) on the outer flange rim

Further, apply minimum 2 wrappings STOPAQ® Wrappingband CZ (H) on the outside of the flange in such a way that the bolts- and nuts ends (which are covered with a layer of STOPAQ® FN 4100) are extra protected by the STOPAQ® Wrappingband CZ (H). The last coating is overlapped by 100mm. Then spark with 15 kV or 20 kV.

Application STOPAQ® Geotextile over the STOPAQ® FN 4100

Achievement of extra mechanical strength is done by wrapping it all with the STOPAQ® Geotextile and its covering foil. The STOPAQ® Geotextile is cut to size.

Length: 3.2 x flange diameter. Width: bulb + (2 x 50mm). Fold the STOPAQ® Geotextile around the STOPAQ® FN 4100 to the bulb shape. The STOPAQ® Geotextile must overlap itself minimum 50mm. The STOPAQ® Geotextile must cover 50mm of the adjoining STOPAQ® Wrappingband CZ (H). Fasten the STOPAQ® Geotextile to the STOPAQ® Wrappingband CZ (H).

Application STOPAQ® Covering tape over the STOPAQ® Geotextile

The STOPAQ® Geotextile covered flange is further completely wrapped by cross layers of STOPAQ® Covering tape. The STOPAQ® Geotextile is now fully covered.

Application STOPAQ® Covering tape over the STOPAQ® Wrappingband CZ (H)

The remaining part of the pipe, which is only covered by STOPAQ® Wrappingband CZ (H), must be finished with STOPAQ® Covering tape, starting at the pipe side with a clearance of 3mm STOPAQ® Wrappingband CZ (H). For this purpose STOPAQ® Covering tape is used. The overlap is 50%. 30mm is wrapped around the applied STOPAQ® Covering tape.

See Also

Login Status

You are not currently logged-in. Please Register & Log-in to download documentation.