Restoring Fire Main Integrity with Triple7 EnviroScale

At first glance…

Maintaining seawater system integrity is critical to platform safety and operational readiness within the Royal Australian Navy fleet.

Envirofluid recently supported a Fire Main system flush onboard an Australian Navy vessel as part of a scheduled maintenance cycle. The system, seawater-filled and uncleaned for approximately five years, had developed heavy fouling from algae, calcium, and organic deposits.

By introducing Triple7 EnviroScale, a certified bio-based, non-corrosive descaling chemistry, Envirofluid delivered a controlled, compliant, and risk-free cleaning outcome—proving a viable replacement for HAZMAT-classified, corrosive, and Dangerous Goods (DG) products traditionally used in these operations.

Here’s the story…

Fire Main networks are essential shipborne systems that ensure rapid firefighting capability and cooling water circulation. Over time, seawater exposure causes significant scaling, corrosion, and biological growth—particularly within dead legs, where stagnant fluid leads to sediment and biofilm accumulation.

Past system cleans using corrosive acids have resulted in asset damage and safety incidents across the naval fleet.
An Australian Navy Executive Summary Paper on scale removers documented several such events:

• Electrical room flooding due to corroded Fire Main pipework
• Damage to critical documentation stores
• Personnel exposure incidents caused by acid leaks
• Corrosion of “dead legs” from residual acid
• Extensive pump damage and asset degradation

A separate Defence contractor report also linked aggressive acid descalers to corrosion of 316 stainless steel, aluminium framing, and plastic valves—confirming the need for a safer, non-corrosive alternative that maintains operational effectiveness without compromising material integrity.

Approach: The Solution

Envirofluid implemented its Triple7 EnviroScale system-flushing protocol, delivering a compliant, non-DG process tailored to Defence maintenance and environmental requirements.

Supplies and Equipment

Triple7 EnviroScale

• Certified bio-based, non-corrosive descaler for metal and composite systems
• Effectively removes calcium, rust, and marine biofilm
• Compatible with aluminium, copper, brass, and stainless substrates
• Non-toxic, VOC-free, and fully biodegradable

Support Equipment

• Controlled recirculation pump array for uniform flow
• Inline filtration to verify effluent clarity and debris capture
• Sampling points for SPO verification and analysis

Execution

Procedure Overview

• The Fire Main zone was isolated and prepared for closed-loop circulation.
• Triple7 EnviroScale was introduced to dissolve scale, algae, and organic build-up throughout the network, including dead-leg sections.
• The system was flushed and neutralised through multiple rinse cycles until effluent met conductivity and clarity parameters.
• A Systems Program Office (SPO) hold-point inspection validated that all operational and material acceptance criteria were achieved.

Performance Observations

• Complete removal of marine growth and inorganic fouling
• Improved hydraulic flow and system efficiency
• No evidence of material degradation or surface etching
• Reduced downtime through rapid inspection approval

Safety and Environmental Compliance

The operation achieved Defence-level compliance while significantly reducing risk:

• Non-Toxic and Non-Corrosive: Eliminated personnel and asset hazards.
• Certified Bio-Based Chemistry: Aligned with Defence sustainability and net-zero targets.
• No DG Classification: Simplified onboard logistics, transport, and disposal.
• Low Odour, VOC-Free: Improved working environment within confined compartments.

“The flush achieved outstanding results—system flow restored, surfaces clean, and no residual acid detected. EnviroScale demonstrated that effective maintenance doesn’t have to compromise safety.”

– Defence Maintenance Engineer

Operational Outcome

The Fire Main restoration reinstated the system’s full design capability and validated Envirofluid’s method as a compliant, repeatable, and scalable maintenance process for Defence maritime platforms.

Operational benefits included:

• Restored System Integrity: Removal of corrosion products and fouling without structural impact.
• Reduced Maintenance Risk: No DG handling, neutralisation, or waste-treatment hazards.
• Extended Asset Life: Prevention of metal loss and sealing degradation common with acidic descalers.
• Optimised Availability: Shorter maintenance duration and faster recommissioning.

This outcome demonstrates how bio-based chemistries can enhance platform sustainment by combining technical performance with occupational and environmental safety.

Advancing Defence Capability Sustainment

Building on this success, Envirofluid is developing a System Flushing Work Pack in collaboration with Defence industry partners, including Babcock. This program aims to standardise non-hazardous flushing methodologies across multiple shipboard systems—Fire Main, HVAC, ballast, and auxiliary cooling—delivering measurable value for money (VFM), consistent compliance, and improved through-life asset performance.

Envirofluid continues to support the Australian Defence Force with sovereign, sustainable maintenance solutions—keeping platforms mission-ready while protecting personnel, infrastructure, and the environment.

Need a safer, compliant alternative for your Fire Main or seawater systems?

Envirofluid’s Triple7 EnviroScale offers a certified bio-based, non-corrosive solution proven across Australian Navy maintenance programs.

Connect with our Defence Support Team to discuss integration of the System Flushing Work Pack into your platform sustainment plan.