AMPP SP21472 : 2026

Scope and Rationale

Scope

This standard describes the AMPP recommendations for water treatment to prevent internal corrosion of pipelines, risers, and subsea equipment during hydrotesting or when the infrastructure is filled with water and there is a need to prevent corrosion and biological growth onshore and offshore; commonly referred to as wet lay-up, wet parking, or wet storage. This SP is intended to provide requirements and educate the user on the important considerations associated with these activities.

The primary purposes of the hydrotest/lay-up water treatment are the mitigation of internal corrosion and the maintenance of asset integrity over the asset service life. While proper disposal of treated water can be costly, improper disposal of such water can be environmentally hazardous, and perhaps even more costly. The owner/user should recognize the overall benefits of achieving full or extended service life when planning hydrotests or wet lay-up operations.

This standard is divided into information on water quality supporting the reasoning why instructions are provided, general guidance that applies to onshore and offshore hydrotesting or wet lay-up, and information that is specific to hydrotesting or wet lay-up for onshore or offshore. General guidance is to be followed in all instances, supplemented by the onshore or offshore guidance based on the specific location.

Rationale

As part of hydrotesting operations, situations arise where the selected hydrotest water can remain in the subject lines for prolonged periods of time. This could potentially cause issues that impact the long-term integrity and service life of the lines. The proper selection of hydrotest water, the right methodology of treatment to mitigate fouling, corrosion (both general and microbiologically induced), and other detrimental issues that could impact the long-term integrity of the equipment are critical. This standard practice is designed to aid in setting organizational requirements for the selection, treatment, and disposal of hydrotest water for long-term wet lay-up of onshore and offshore pipelines, risers, and subsea equipment.