8/20/2019 TR Reinert Ritz Turkey Project

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8/20/2019 TR Reinert Ritz Turkey Project

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TECHNICAL REPORT JOINING TECHNOLOGY

Figure 2: Left: completed stub end at Reinert-Ritz right: stub end, complete with steel encapsulation, pipe extension and bracing

months. Three extrusion machines have been operating in

parallel in this purpose-built facility. This system not only achie-

ves cost benefits, but also for many projects, it provides an

assurance factor both desirable and in many cases mandatory.The pipe length results from the fact that PE pipes, due to

their specific gravity of less than 1 g/cm3, would normally

float on the surface of the water. This fact, in combination

with the lower relative density of freshwater compared to

seawater, causes enormous positive buoyancy forces. These

are counteracted by the pipe joining yokes, each consisting of

two flanged connectors and a steel pipe bend to which the

flanged connector is fixed. The steel yokes have an outside

diameter of 1,514 mm, a curvature radius of 8,000 mm with a

bend angle of 30°, and weigh around 10 tonnes without the

connecting elements. Total weight including the two connec-

ting elements is around 13 tonnes. The steels yokes, which alsoact as fixing and anchoring points, are subsequently drawn

down to a depth of 250 m by means of steel cables and then

anchored to the seabed (Figure 1), illustrating even better the

special features of this project.

The specially made flange connectors are welded on to the

long PE pipes on site and bolted to the steel pipe yokes by

means of a steel flange provided specifically for this purpose.

This yoke is then anchored to the seabed by means of steel

Figure 3: Pipe sections waiting for transport 

8/20/2019 TR Reinert Ritz Turkey Project

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JOINING TECHNOLOGY TECHNICAL REPORT

cables to the securing and anchoring point. The challenge

for Reinert-Ritz was that of providing a product to join the

PE pipes and steel yokes durably and securely such order that

even the most adverse conditions encountered underwater

in the Mediterranean could not impair the connection. At a

depth of around 250 m, this design involves the following

technical challenges: buoyancy forces exerted by the PE 100

pipeline; powerful and dynamic sea currents, high shipping

(and submarine) traffic frequency, potential of earthquakes,

and the 7 bar operating pressure.

Decision for high quality and safety

The Nordhorn company is the specialist for semi-finished

products and full pressure rated fittings conforming to the

specified pressure classification for large dimensions up to an

outside diameter of d 2000 mm; hence the right address for

solutions to demanding problems. With over forty years ofexperience in plastics and the company’s pronounced qua-

lity awareness, the definitive arguments are established for

initiating the co-operation between the project planner and

Reinert-Ritz. From the high-quality granulate, used for produc-

tion of the semi-finished products, through to the machining

of the finished stub ends, the company was able, with its

all- encompassing Quality Assurance system, to guarantee

the high production standards vital for the performance and

completion of this demanding project. This high quality con-

sciousness has been shaped, in particular, by work for the gas

industry in Germany, one of the first customers for PE, which

makes use of this material and its high flexural strength in areassubject to mining subsidence. Only then did the safety and

cost benefits result - within just fifty years - in PE‘s leadership

on the supply-systems market.

It is therefore not surprising that ever more positive experience

is being accumulated, with the application of PE pressure-pipe

systems in large-scale industrial fire-extinguishing installations

and power-generation plants, including the nuclear-energy

industry.

There are two production routes for these full pressure- rated

fittings: injection moulding and machining. The hollow bars

and solid rods made by Reinert-Ritz are used in the latter

process. This method assures a product free of voids and

incorporating more than forty years of design and processingexperience.

Solution of the complex flange concept

Production of hollow bars of 1,900/1,400 mm, with a wall

thickness of approx. 250 mm, is the first stage in the fabri-

cation of the special flanged connection. Subsequent machi-

ning takes place on a milling machine capable of processing

material up to sizes of 2,800 x 1,500 x 4,800 mm. A particular

challenge was presented by the large dimensions of the PE

pipeline fitting and the extremely high dimensional accuracy

demanded; tolerances of 0.0 mm and +0.5 mm. On site in

Turkey, the finished PE 100 stub end is enclosed geometri-cally secured in two steel clamping assemblies, into which it

must fit perfectly. The high-precision flanged connectors are

assembled on a special installation ship, with twenty-four

connecting bolts, on both ends of the steel yoke. The yoke is

then anchored to the seabed, to enable the pressure pipeline

to „float“ at an average depth of 250 m.

ConclusionThe precondition for the success of this project was the suc-

cessful evolution for the ultra-demanding innovative flange

design of a PE 100 fitting which would durably join steel and

PE 100. The extreme dynamic loads to which the flanged

connection is exposed in underwater service were, above all,

taken into account in development. Excel- lent communica-

tions and co-operation between Reinert-Ritz and the project

planners achieved successful in-company installation and have

generated an extremely high level of confidence for the long-

term tightness and safety of the flanged connection.

CONTACT: REINERT-RITZ GmbH, Nordhorn, GermanyTel. +49 5921 83470, E-Mail: contact@reinert-ritz.com

www.reinert-ritz.com

B6, 143

Figure 4: A 500 m pipe section in Turkey connecting bolts, on both

ends of the steel yoke. The yoke is then anchored to the seabed, to

enable the pressure pipeline to „float“ at an average depth of 250 m