The Ultimate Drydock Checklist: What to Replace Before You Relaunch

A successful drydock is rarely defined by what happens in the yard. It is defined by what does not go wrong after the vessel relaunches.

Picture this. The drydock wraps up on schedule. The vessel is back in service. Everything looks good. Until weeks or months later, a small leak appears. Then a compliance issue. Then a system failure that forces the vessel back out of operation.

What felt like a successful drydock quickly turns into unplanned downtime.

In many cases, the root cause is not poor workmanship. It is critical flow components that were left in place because they looked acceptable at the time or were difficult to access once the schedule tightened.

This checklist is designed to help shipowners, operators, and shipyard teams focus on the flow components that deserve attention while access is available, so relaunch is smooth, compliant, and predictable.

Why Flow Components Deserve Early Attention

Flow systems work quietly until they do not. During drydock, access to piping systems, tanks, and machinery spaces creates a rare opportunity to address components that are difficult or costly to service while afloat.

Common post relaunch issues often trace back to components that were left in place because they looked acceptable at first glance or were deferred to save time.

The reality is simple. If it is aging, difficult to access, or critical to system integrity, drydock is the moment to act.

The Drydock Flow Readiness Checklist

Use this checklist as a starting point when planning inspections and replacements.

Valves

Valves regulate flow, pressure, and safety across nearly every onboard system. During drydock, valves should be evaluated for both mechanical condition and operational performance.

Inspect or replace if you see:

• Stiff operation or seized stems
• Internal corrosion or pitting
• Leakage at the seat or packing
• Outdated designs that no longer meet efficiency or balancing requirements

For improved efficiency, smart balancing and control solutions such as Frese valves automatically regulate flow, reduce energy loss, and minimize post relaunch adjustments, delivering cost savings.

Vent Heads and Tank Ventilation

Vent heads are often overlooked because they sit quietly until they fail. However, improper ventilation can create serious safety and compliance risks.

Inspect or replace if you see:

• Corrosion on housings or internal floats
• Blocked or restricted airflow
• Evidence of water ingress into tanks
• Older vent designs without reliable float mechanisms

Pipe Couplings and Flexible Connections

Pipe couplings are used to join pipe sections while allowing for limited movement, vibration, and thermal expansion in operating systems. Over time, wear and fatigue can reduce their ability to maintain a secure, leak free connection.

Inspect or replace pipe couplings if you notice:

• Cracks, hardening, or deterioration in sealing elements
• Signs of stress from pipe misalignment
• Excessive noise or vibration during operation
• Couplings that would require hot work to repair or replace

Press Fittings and Pipe Connection Points

Press and mechanical pipe fittings create permanent, leak free connections in critical onboard piping systems. While small in size, failures at these connection points can shut down entire systems.

Inspect or replace press or mechanical fittings if you see:

• Corrosion at threaded or pressed connections
• Evidence of past leaks or temporary repairs
• Mixed standards or aging materials
• Areas where future access would be limited

Ship Checks: Plan Before the Dock Date

Ship Checks are designed to solve this problem before it starts.

This consultative service takes place ahead of drydock and focuses on identifying exactly which valves, vent heads, couplings, and fittings should be addressed while access is available.

Ship Checks help:

1. Identify aging or high risk components early
2. Reduce scope creep during drydock
3. Prevent last minute sourcing and substitutions
4. Ensure correct specifications and approvals
5. Support smoother, faster relaunches

Instead of reacting to issues during drydock, Ship Checks allow teams to plan proactively and execute with confidence.

Plan Once. Relaunch Once.

Drydock success is not just about what gets done. It is about what does not have to be revisited after the vessel is back in service.

By addressing critical flow components upfront and leveraging expert guidance before the dock date, shipowners and operators can avoid costly surprises and keep operations moving forward.