Can high pressure water jetting be performed safely in a confined space?

Yes, high pressure water jetting can be performed safely in a confined space, but it requires significantly more planning, equipment, and coordination than open-area jetting. The combination of restricted access, limited ventilation, and the inherent hazards of operating at pressures between 500 and 3000 bar “7,250 and 43,500 PSI” makes confined space jetting one of the most demanding operations in industrial cleaning. The sections below walk through the key hazards, regulations, equipment requirements, and planning steps that make safe confined space jetting possible. If you want to discuss your specific situation, feel free to contact our team directly.

What are the main hazards of water jetting in a confined space?

The main hazards of high pressure water jetting in a confined space include:

• Oxygen deficiency due to displaced air from residues, rust reactions, or biological matter
• Toxic or flammable atmospheres that can develop with little warning when sludge is disturbed
• Restricted movement that significantly increases injection injury risk
• Noise amplification inside enclosed metal structures, causing hearing damage and impairing decision-making
• Difficulty of emergency evacuation if an operator becomes incapacitated

These hazards compound one another, meaning a single equipment malfunction can quickly escalate into a life-threatening situation.

In open environments, many of these risks are manageable through distance and ventilation. Inside a confined space, such as a tank, vessel, pipe, or silo, the dynamics change dramatically. Residues from previous contents, rust reactions, or biological matter can displace oxygen or release toxic vapours, and high pressure jetting can disturb settled sludge and release gases with little warning. At the same time, a water jet operating at even 500 bar “7,250 PSI” can penetrate skin and tissue instantly, and the restricted movement inside a confined space makes it significantly harder for an operator to maintain safe positioning or react quickly if a hose or nozzle shifts unexpectedly.

Hard surfaces in tanks and vessels amplify noise to levels that cause hearing damage over prolonged exposure, and the disorientation this creates can impair safe decision-making at critical moments. Wet surfaces, limited lighting, and awkward working postures compound this by increasing the risk of slips and falls — particularly dangerous when a high pressure lance is in hand. If a hose fitting fails under pressure, the resulting whip in a confined space leaves no room to move clear of the hazard. And should an operator become incapacitated, rescuers face significant delays due to restricted entry and exit points, which is why standby rescue provisions are an absolute requirement, not an optional precaution.

Understanding these hazards is the foundation of every safe confined space jetting plan. No amount of operational experience replaces a thorough hazard assessment before entry.

What safety regulations apply to confined space water jetting?

Confined space water jetting is governed by a combination of national confined space regulations and industry-specific water jetting safety standards. In practice, operators must comply with both sets of requirements simultaneously, and the more stringent rule always applies.

Several organisations publish guidance and standards directly relevant to high pressure safety in confined space jetting operations:

• SIR (Netherlands): The Stichting Inspectie Risicobeheersing provides national guidelines for risk management in industrial operations, including confined space entry and high pressure work.
• EWJI (Europe): The European Water Jetting Institute sets pan-European best practice standards covering equipment, operator competency, and confined space protocols.
• WJA (UK): The Water Jetting Association publishes detailed codes of practice that address confined space jetting specifically, including standby arrangements and permit-to-work requirements.
• WJTA (USA): The WaterJet Technology Association provides recommended practices that are widely referenced internationally.
• DIRV (Germany): The Deutsches Institut für Regelungen und Vorschriften provides the regulatory context for water jetting and confined space work in industrial environments.

Beyond these water jetting bodies, national occupational health and safety legislation in each country typically mandates a formal confined space permit-to-work system, atmospheric testing before and during entry, a trained attendant stationed outside the space at all times, and a documented emergency rescue plan. Operators should always verify which national regulations apply to their specific site and cross-reference them with the relevant water jetting standards.

What equipment is required for safe confined space jetting?

Safe confined space water jetting requires personal protective equipment rated for high pressure exposure, atmospheric monitoring instruments, ventilation equipment, communication systems, and a rescue kit positioned at the entry point. The jetting equipment itself must also include specific safety features suited to confined space use.

Personal protective equipment

Operators entering a confined space for jetting work need full-body waterproof protective suits, high pressure rated gloves, and face protection. Footwear must be non-slip and waterproof. Hearing protection is essential given the amplified noise levels inside enclosed metal structures. Depending on atmospheric conditions, a supplied-air breathing apparatus or self-contained breathing apparatus may be required rather than a simple dust mask.

Jetting equipment and safety features

The jetting unit itself should be fitted with a deadman control, also called an automatic stop valve, that immediately cuts water flow if the operator releases the trigger. This is a critical safety feature in any jetting operation, but it becomes especially important in a confined space where an incapacitated operator cannot be reached quickly. Key requirements for jetting equipment include:

• Hose assemblies rated for the operating pressure, inspected before each use, and secured to prevent whip
• Nozzle selection that accounts for the geometry of the confined space to avoid uncontrolled jet deflection
• Remote-operated tooling for pressures approaching 3000 bar “43,500 PSI”, strongly preferred over hand-held lances

Monitoring and communication

A continuous atmospheric monitor measuring oxygen levels, flammable gases, and toxic vapours must be worn by the operator or mounted at working height inside the space. A reliable two-way communication system between the operator inside and the attendant outside is not optional. If verbal communication is not possible due to noise, a pre-agreed signal system using rope tugs or a radio system designed for noisy environments must be established before entry.

How should a confined space water jetting operation be planned?

A confined space water jetting operation should be planned using a structured permit-to-work process that begins with hazard identification and ends only when the space has been cleared and all personnel are accounted for. Planning is not a formality; it is the primary safety control for this type of work.

The key stages of a confined space jetting plan are:

• Hazard identification and risk assessment: Document all potential hazards specific to the space — including its previous contents, geometry, access points, and proximity to other processes — along with the controls assigned to each hazard before work begins.
• Atmospheric testing: Carried out before any person enters and continued throughout the operation, either continuously via a monitor worn by the operator or at defined intervals.
• Isolation and lockout: All pipework, electrical equipment, and mechanical systems connected to the confined space must be isolated and locked out before entry, covering any system capable of introducing gases, liquids, or energy into the space.
• Permit-to-work: A competent person must issue and sign off the permit, defining the scope of work, the personnel involved, the permitted duration, and the conditions under which work must stop.
• Emergency rescue procedure: A documented plan must be in place before entry begins — including a trained standby attendant outside the space, rescue equipment at the entry point, and a clear escalation path if the attendant cannot retrieve the operator without entering.
• Briefing: Every person involved, including the operator, the attendant, and the equipment operator, must be fully briefed on the plan, the hazards, and the emergency procedure before work starts.

After jetting is complete, the space must be ventilated, re-tested, and formally cleared before any further work or entry takes place.

Can robotic or remote-controlled jetting systems reduce confined space risk?

Yes, robotic and remote-controlled jetting systems can significantly reduce confined space risk by removing operators from the hazardous environment entirely or limiting their time inside. This is one of the most effective risk reduction strategies available for confined space cleaning operations.

When a robotic system handles the jetting work, the operator controls the process from outside the confined space. This eliminates exposure to injection injury, noise, toxic atmospheres, and the physical strain of working in a restricted environment. It also removes the need for a rescue plan focused on extracting an incapacitated person from inside the space, since no person is present during active jetting. Robotic systems are particularly well suited to:

• Tanks and vessels with regular internal geometry
• Long pipe runs cleaned with lance-fed or crawler-based systems
• Operations at pressures above 1000 bar “14,500 PSI” where hand-held operation carries elevated injury risk
• Repetitive cleaning cycles where consistent coverage is critical

Our MagTrack robotic system is one example of how remote-controlled technology is being applied to exactly these challenges. It uses magnetic adhesion to navigate vertical and curved surfaces inside vessels and tanks, keeping operators clear of the jetting zone while maintaining precise cleaning coverage. You can explore our full range of jetting products and systems to see what options are available for your application.

It is worth noting that robotic systems do not eliminate all confined space hazards. The space still needs to be assessed, isolated, and monitored. However, the risk profile is substantially lower when the primary operator remains outside.

What training do operators need for confined space water jetting?

Operators performing high pressure water jetting in confined spaces need two distinct areas of certified training: confined space entry and rescue, and water jetting competency at the relevant pressure range. Both must be current, and neither substitutes for the other.

Confined space training

Confined space training covers hazard recognition, atmospheric testing, use of breathing apparatus, emergency rescue procedures, and the permit-to-work system. In most countries, this training must be delivered by an accredited provider and renewed at defined intervals. The standby attendant also requires training, even though they do not enter the space, because they are responsible for monitoring the operator and initiating rescue if needed.

Water jetting competency

Water jetting training covers safe equipment operation, nozzle selection, hose management, deadman control use, and emergency shutdown procedures. Organisations such as the EWJI, WJA, WJTA, DIRV, and SIR each publish competency frameworks and training standards for water jetting operators. Important points to note:

• Training must be matched to the pressure range the operator will actually work in — an operator trained for work up to 500 bar “7,250 PSI” is not automatically qualified to operate equipment at 2000 bar “29,000 PSI” or above.
• Refresher training and toolbox talks before each confined space jetting operation are strongly recommended even for experienced operators, since conditions vary between sites.
• A pre-job briefing reinforces the specific hazards and controls relevant to that day’s work.

How DERC Salotech supports safe confined space water jetting

We have been engineering high pressure water jetting solutions for over 40 years, and confined space applications are among the most technically demanding challenges our customers face. We understand that safety and operational performance are not competing priorities; the right equipment and preparation deliver both.

Our jetting systems are engineered for the pressure ranges and conditions found in real industrial confined space work, from 500 bar “7,250 PSI” entry-level applications up to 3000 bar “43,500 PSI” for the most demanding cleaning tasks. Here is how we support safe confined space operations:

• Our MagTrack system and other remote tooling options reduce or eliminate the need for operators to be present inside the jetting zone.
• Our range of high pressure nozzles includes options specifically suited to confined space geometry, reducing the risk of uncontrolled jet deflection.
• Our equipment meets both metric and SAE standards, integrating with existing site infrastructure regardless of location.
• Through our subsidiary DERC Adviesgroep, we offer certified training courses aligned with the standards set by SIR, EWJI, WJA, WJTA, and DIRV.
• We work directly with customers to configure equipment that matches their specific confined space geometry, pressure requirements, and safety protocols.

If you are planning a confined space jetting operation and want to discuss the right equipment or training approach for your situation, we are ready to help. Get in touch with our team and we will work with you to find a solution that puts safety and efficiency first.