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Staying grounded

Published by , Editorial Assistant
World Pipelines,


Essam Arfaj, Bader Jarallah, and Mohanned Tarabzouni, Aramco, Saudi Arabia, weigh in on the debate between installing pipeline valves above-ground, underground, or in a valve box.

Staying grounded

With the advancements in pipeline construction methods and inline inspection tools, end users have found themselves in a debate around optimising pipeline installation methods – such as buried (underground) or above-ground installation. This has also expanded to the selection of valve installation methods, which include the aforementioned buried and above-ground installation, in addition to the boxed installation option. Several factors determine the most appropriate method, such as environmental protection and damage prevention, routing, population density, and safety hazards. While buried pipelines have become the preferred method for most end users, valve installation methods are still a point of debate. This article will shed light on the pros and cons for each, as well as a thorough review of key factors involved in the final decision-making process.

Pipeline installation methods

Installing pipelines is essential for safely transporting fluids and gases in various industries, especially the hydrocarbon industry. For underground pipelines, it is crucial to analyse soil conditions to prevent corrosion and ensure stability. Minimising environmental impact and following local regulations are also important steps, including obtaining the necessary permits. For above-ground pipelines, structural support is key to preventing sagging and maintaining alignment. Pipes need protection from environmental factors like weather and temperature changes and accessibility is crucial for maintenance and inspections.

Overall, understanding the specific challenges and requirements of both underground and above-ground installations is vital for a successful, compliant, and efficient pipeline system. Regular inspections and maintenance protocols are essential to catch potential issues early and ensure long-term operation. Implementing safety measures protects both workers and the environment during the installation and throughout the pipeline’s operation.

The US, for example, houses one of the largest pipeline networks in the world with more than 3 million miles of pipes transporting hydrocarbon products across the country. The majority of these pipelines are buried below ground to safely carry and deliver products to end users.

In Saudi Arabia, this is also the case, as the majority of the over 25 000 km pipeline system is buried below ground, spread across the Kingdom and passing through multiple elevation changes, natural habitats and harsh desert environment.

Valve installation methods

While pipeline methods are generally clear to assess and select, installing valves in pipeline systems is a critical process that ensures the safe and efficient control of fluid flow. Proper installation is crucial, regardless of whether the valves are installed underground, above ground, or within a valve box. This article provides an overview of the considerations and steps involved in each type of installation. Typical methods of valves installation include the following:

Underground valve installation

Underground installation of valves entails completely burying the valve alongside the welded pipeline with extensions of auxiliaries above ground. In most cases, the depth of the valve and extended auxiliaries vary in length and design to accommodate and ensure the operability of the valve. Several design factors must be considered for underground installation, including, but not limited to, the following:

    Soil conditions: ensuring the soil can support the valve without causing corrosion or damage.
    Accessibility: allowing future access to the valve for maintenance, inspection or emergency responses.
    Protection: applying the required protective coatings or wrapping system to safeguard against corrosion.
    Environmental impact: minimising disruptions and protecting the environment.

Above-ground valve installation

    On the other hand, above-ground installation in a fenced or designated location for valves is another potential option. This is a commonly used option among end users, due to the accessibility of the valve and associated components. This option depends on multiple considerations in design and construction, including the following:
    Environmental exposure: protecting the valve from environmental factors such as harsh weather and temperature fluctuations.
    Accessibility: ensuring that the valve is easily accessible for operation and maintenance.
    Security: protecting against vandalism and third-party damage.
    Civil structure: supporting the design to ensure the valve withstands and is aligned with all loads.
    Preparation: flanged connections with potential leak paths, requiring proper torqueing and commissioning.

Valve box installation

The third installation option is installing the valve in a solid box, mainly made of concrete. The box is typically a concrete structure (or pit) equipped with a manhole or other access point that allows easy access to the equipment located within the vault. Access to the box is usually through a ladder, allowing inspection or maintenance on the pipe, valves, meters, or other equipment. The valve body itself is directly buried in the ground or soil.

This means the valve will be in a confined space, which increases the risks of operational hazards and unsafe work conditions when inspecting and maintaining the valve. Several factors must also be considered, such as:

    Material: choosing a durable material for the valve box to withstand environmental conditions.
    Size and fit: ensuring the valve box is appropriately sized to allow easy access to the valve.
    Site preparation: clearing and levelling the area where the valve box will be installed.
    Position: positioning the valve box over the valve to ensure that the valve is easily accessible.
    Security: securing the valve box to prevent movement and protect the valve from external damage.
    Labelling: clearly labelling the valve box for easy identification.

Additionally, CAPEX for valves may be higher with this option compared to the previous two, as it includes requirements similar to both above- and below-ground installation, such as the casing design, associated coating system, confined space restrictions, extended valve operator, and the internal layout of the box.

Regardless of the installation type, regular maintenance and inspection are vital to ensure the longevity and proper functioning of the valves. Depending on the maintenance and inspection strategies, these valves will require proactive approaches to ensure their integrity and readiness during normal and emergency operations.

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Read the article online at: https://www.worldpipelines.com/special-reports/24012025/staying-grounded/

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