Installation of Rubber Pipe on Pipeways
Rubber pipes are normally designed such that they can be installed on pipe routes with the same support intervals as those used in installation of steel pipes. The minimum permissible interval between supports is dependent on the pipe’s nominal diameter.
Clamps or other support components used with steel pipe are also suited for use with rubber pipe. In this regard keep in mind that the outer diameter of rubber pipes is normally larger than that of steel pipe of equal nominal (inner) diameter. When installing rubber pipelines in existing pipeline systems and on existing pipeways, adaptation or replacement of supporting elements may be required.
GUR rubber pipelines are self-compensating. Their special steel reinforcement system ensures that thermal expansion at elevated temperatures is alleviated by transformation to elastic strain within the rubber pipe segment. This provides users significant advantages by eliminating the need for compensators in the pipeline. In effect, the pipeline itself is the compensator.
As a result of this technology, GUR rubber pipelines can be installed by simply bolting in place. Support systems of the simplest designs can be used to support the line. Loose supports, sliding supports and/or horseshoe bends are not required in GUR pipelines.
GUR is specifically designed for installation capability in normal pipe supports as used with steel pipe. Additional support over the length of the pipe e.g. by a half shell or other system is not required. The rubber pipe reliably supports itself as well as its contents over the intervals between the support points. When installing, take care not to damage the outer rubber surface of the pipe as it serves to protect the reinforcement system within against corrosion.
Connecting Rubber Pipe Segments Together or to Other Types of Pipe
Rubber pipes are bolted together without requiring insertion of seals between individual segments. The “O” rings integrated in the rubber sealing surfaces of the pipe segments ensure a dependable pressure-proof seal of the connection. GUR pipes are supplied with FL flanges as standard equipment, GUR components are also available with flange type FR. The installation information provided is valid for both flange types.
The tightening torque required for a secure and pressure-tight connection is 70 Nm up to DN 300 and 120 Nm up to DN 500. Required tightening torques for larger diameters can be provided on request.
In general, when installing GUR pipe, take care not to damage the rubber sealing surfaces by excessive tightening torque. Do not compress the rubber seals by more than 20 % of their original thickness. When installing large diameter GUR pipe, use a feeler gauge to avoid exceeding this maximum permissible compression.
When bolting rubber pipes follow generally accepted technical practice, e.g. bolt up gradually and evenly at opposite sides (12 o’clock, 6 o’clock, 9 o’clock, 3 o’clock, etc.) and avoid tilting of the flange.
Connect GUR components to steel or plastic pipes using the same procedure. When connecting to pipe made of these materials, do not use additional seals other than those already integrated in the GUR pipe segments. Specifically do not use rigid seals between GUR flanges and steel flanges as they impair the sealing integrity of the connection.
note for GUR KR Compensating Reducers:
When installing GUR KR compensating reducers and GUR K compensators connect the pump side first, complying with the specified tightening torques. When installing on the suction (i.e. horizontal) side, be certain that the component is exactly horizontal and suitably supported on its free end to ensure distortion-free installation.
Then assemble the pipeline, conforming with the specified clearance gaps to the rubber pipe components. These clearance gaps are required to ensure proper functioning of the compensators. A gap of 6 mm is required for diameters up to DN 500, for larger diameters up to DN 1200, a gap of 10 mm is required. After the pipeline is assembled in this manner, tighten the flanges only enough to close the gaps. Then tighten the bolts fully with the specified tightening torque.
Rubber Pipelines on Buoyant Pontoons
An important application sector for our Series 1 rubber pipes is hydraulic transport pipelines for gravel and sand mined by dredging barges. The transport pipeline between the barge and the transfer station on land is normally supported by buoyant pontoons. GUR rubber pipes can be used with the same pontoons as those used with steel pipe. In general avoid installing rubber pipe with excessive overhang over the pontoons. The overhang should not exceed 2 meters.
When installing it is expedient to first place and fix the rubber pipes on the pontoons before then installing the completed pipe/pontoon units into the pipeline.
Should the need arise to install a single rubber pipe segment or individual pipe segments in a long steel pipeline, we strongly recommend to include tube segments between the rubber and steel pipelines. Rubber pipe alone is not capable of withstanding the flexing angles encountered occasionally in the course of installation work.
When building mixed pipelines, take into account the differences between rubber and steel in terms of their flexural properties. Since rubber pipe is more flexible than steel pipe, pipeline flexing caused by high winds will be found almost exclusively in the rubber pipeline. In other words, high winds will cause much greater bending in the rubber part of the line as compared to the steel part. This is not critical unless the rubber pipe completely kinks. To prevent this, do not connect steel pipes and rubber pipes in a directly adjacent configuration. Install a flexible tube in between which can substantially alleviate the flexing forces.
If the rubber part of the pipeline makes up more than 75 % of the overall pipeline length, it will be able to withstand the flexing without need for an intermediate tube segment. GUR pipelines exhibit outstanding tensile strength and high resistance to wind pressure. A particular advantage they offer over steel pipelines is that they return to their original shape when the wind pressure subsides. They are not subject to permanent deformation following exposure to high winds as can occur with steel pipes.
GUR rubber pipe segments are normally supplied with loose flanges on both ends. The loose flanges are essential for ease of connection – even over water – as they permit simple alignment of the bolt holes. The fact that no additional seals are required further facilitates installation.