SylShield Pipe Weld & Protection Wrap protects a natural gas pipeline in Czech Republic before it underwent trenchless installation via horizontal directional drilling

Czech Republic Natural Gas Pipeline Protection Before Trenchless Pipe Installation

A 150mm diameter steel natural gas pipeline is given protection against impact damage and scarring before being rerouted beneath a river and road via trenchless pipe installation as part of a project to improve energy security in the Czech Republic.

Case Study Overview

Site Natural gas pipeline
Location Czech Republic
Pipe Type 150mm diameter stainless steel
Repair Type Pipe weld and pipeline protection
Products SylShield Pipe Weld & Protection Wrap

A natural gas pipeline in Czechia undergoes pipe weld protection ahead of horizontal directional drilling using SylShield

Pipe Defect

The natural gas pipeline in the south of the Czech Republic was being rerouted to improve energy security for the country. Its new path ran beneath a river and a road, meaning that trenchless pipe installation was required to reduce surface disruption.

It was decided to use horizontal directional drilling. This involved welding numerous separate sections of the pipe together above ground. The completed line is then pulled through a borehole, installing it below the river and road without the need to dig any trenches.

Horizontal directional drilling is an intense process which can cause impact damage and scarring to pipes as they are dragged underground. Pipes which are installed via this method therefore require significant levels of protection.

An epoxy coating and a 3mm thick fibreglass composite were applied to the various sections of 150mm diameter steel pipe before they were welded together. Shielding the welded joints was far more challenging as these could not be covered with any type of factory applied protection.

A steel natural gas pipeline in Czech Republic before undergoing protection with SylShield followed by trenchless pipe installation
The pipeline arrived at site as separate sections to be welded together
An epoxy coating and fibreglass composite were added. However, these could not be used to protect the welded joints (black section)

SylWrap Solution

The company installing the line were a long-time client of Sylmasta. They enquired about a SylWrap solution for protecting the welded joints, in addition to the heat shrink sleeves used as standard.

SylShield Pipe & Weld Protection Wrap has been specifically designed for the protection of pipelines during trenchless installation. SylShield is three times the thickness of standard SylWrap Bandage, making it the toughest, most robust composite wrap produced by Sylmasta.

Working to a very tight deadline, the number of SylShield Wraps required for the project were manufactured at Sylmasta’s production facility in the UK on the Thursday.

By Monday morning, they had been shipped and were ready for collection by the installation team from a DHL depot in the Czech Republic.

Each welded joint and heat shrink sleeve was overwrapped with SylShield. The resin was activated with water and SylShield smoothed and wrapped around the pipe. Shrink wrap was applied over the top, securing SylShield to the pipe and improving lamination.

The shrink wrap was spiked, ensuring that gas released during the curing of SylShield could escape rather than being trapped. Within 30 minutes, SylShield had cured to form a rock hard, ultra robust shell encompassing the pipe.

A natural gas pipeline given protection ahead of undergoing trenchless pipe installation via horizontal directional digging
Once the joins had been protected, the pipe was ready to be pulled through the ground and installed via horizontal directional drilling


By Monday evening, the natural gas line had been welded together, protected with SylShield and pulled through the borehole under the road and river.

The trenchless installation had been a success and the pipe needed no repairs after pull back, as can often be the case with horizontal directional digging.

Follow Up

After the repair, the project manager emailed to say: “The installation was a success and we particularly appreciated the timely delivery of the SylShield Wraps. Big thanks to Sylmasta for meeting the tight deadline, which even we thought would be unrealistic.”

Products Used

Toughened composite wrap for protecting pipes undergoing intense installation processes

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