extreme equipment protection: IP68 and higher 

Why the IP68 standard is not a guarantee of survival in real conditions

In our practice of servicing industrial facilities, we regularly encounter a situation where equipment marked IP68 fails after three months of operation. Clients come to us with a complaint: “You sold us protection against water, but the engine burned out.” When opening the case, it turns out that water did not actually get inside during a short-term immersion, but condensation formed due to temperature changes destroyed the electronic board. This is a fundamental misconception of the market: extreme equipment protection IP68 and above is often perceived as an absolute shield, when in fact it is only a basic level of resistance to specific physical impacts under strictly defined laboratory conditions.

If you are selecting sensors, actuators or control cabinets for use underwater, in harsh chemical environments or under high pressure, you need to understand the difference between the marketing label and actual engineering protection. The IEC 60529 standard, which defines IP classes, describes protection against the ingress of solid particles and water, but is silent on corrosion, ultraviolet radiation, vibration and thermal shock. In this article, we'll look at why simply buying an IP68-rated device isn't enough, what hidden risks exist when operating in extreme areas, and how to properly specify the requirements to ensure your equipment lasts for years rather than weeks.

Anatomy of a protection class: what is hidden behind the numbers IP68 and IP69K

Let's immediately understand the terminology to avoid confusion during procurement. The abbreviation IP (Ingress Protection) consists of two numbers. The first number (in our case 6) means complete protection from dust. This is critical in mining or cement plants where fine abrasive dust gets everywhere. The second number (8) indicates the possibility of prolonged immersion in water. However, here lies the first pitfall: the IP68 standard does not record the depth and time of immersion as a single value. The manufacturer himself declares these parameters. One device may be rated for 1 meter for 30 minutes, another for 10 meters for a week. Without specifying these details in the technical specifications, you are buying a “pig in a poke.”

For truly extreme conditions, such as high-pressure cleaning of food processing plants or working in hot water areas, IP68 alone is not enough. This is where the IP69K standard comes into play. It provides protection against high temperature water jets (up to +80°C) and high pressure (up to 100 bar). Unlike static immersion pressure (IP68), the dynamic impact of the jet can rupture seals if they are not reinforced. We have seen cases where valves with IP68 instantly failed after the first sanitary treatment in a meat processing plant precisely because the engineers did not take into account the dynamic pressure factor.

In addition, there is the concept of pressure sealing, which is often confused with IP classes. For subsea equipment operating at depths of more than 50 meters, or for instruments in oil and gas wells, the key parameter becomes pressure in bars or atmospheres, and not simply the fact of immersion. Extreme equipment protection IP68 and higher in such cases must be supplemented by an indication of the operating pressure, for example 10 bar or 100 bar. Ignoring this difference leads to the fact that the housing is deformed (“collapses”) under external pressure, even if water does not formally penetrate through the microcracks immediately.

Critical parameters that are more important than the marking itself

• Temperature range:Rubber seals (O-rings), which provide IP68 sealing, lose elasticity at low temperatures and harden. At -40°C, ordinary rubber turns into glass and cracks at the first mechanical impact. Arctic conditions require special silicones or fluoroelastomers (Viton) that maintain properties down to -60°C.
• Case material:ABS plastic, often used in budget solutions, is destroyed by exposure to ultraviolet radiation and some solvents. For chemical aggression, reinforced polycarbonate or AISI 316L stainless steel is required. Regular 304 steel will rust in seawater within one season, disrupting the geometry of the joints.
• Cable entries:The weakest point of any system. Even if the housing is perfect, an incorrectly selected cable gland will become an entry point for moisture. For extreme conditions, metal bushings with double sealing and cable fixation from being pulled out are required.

When creating a technical specification, always request test reports from the supplier, which indicate specific testing conditions: depth, time, water temperature and the presence of chemically active substances. The phrase “complies with IP68” without attaching a certificate is unacceptable in a serious project.

Real failure scenarios: where theory diverges from practice

One of our clients, a large bottled water manufacturer, experienced widespread failure of level gauges in their tanks. The equipment was IP68 certified. The problem arose not due to water getting inside, but due to the “breathing” effect of the housing. During the day, the tank was heated by the sun, the air inside expanded and came out through micropores. At night, the temperature dropped, creating a vacuum that sucked moist air back in. Within a month, enough condensation had accumulated inside the case to cause a short circuit. This is a classic mistake: protection against liquid water (IP68) is not protection against water vapor and pressure changes.

Another incident occurred on an offshore platform in the North Sea. Pressure sensors in stainless steel metal housings have failed due to galvanic corrosion. Engineers used steel bolts to secure the cover, but did not take into account the contact of dissimilar metals in a salty environment. The electrochemical reaction destroyed the thread within six months, and during a storm the cover was torn off by wave pressure. Here, extreme protection was compromised not by the quality of the device itself, but by errors in fastening materials and the lack of dielectric spacers.

Another common problem is mechanical stress. The IP rating tests sealing, but not impact resistance. A device with IP68 can be made in a fragile case. If a heavy object falls on it or a forklift hits it, the crack will break the seal instantly. For areas with a high probability of mechanical stress (IK impact resistance code) must be at least IK08 or IK10. The combination of IP68 and IK10 is the minimum required standard for equipment operating in heavy industrial workshops or outdoor areas.

We have also seen failures due to improper installation. Installers often overtighten the cover screws, deforming the O-ring. Instead of pressing evenly, the rubber is squeezed to the side, forming a channel for moisture penetration. Or vice versa - they don’t tighten the fasteners enough, hoping for “self-tightening” under water pressure. Both approaches are fatal. Operation requires compliance with the tightening torque specified by the manufacturer and the use of a torque wrench.

Comparative analysis of materials and technologies for extreme environments

The choice of housing material determines 80% of the success in ensuring durability. Below is a comparison of the main solutions used to achieve IP68 and higher protection levels. This analysis is based on our experience supplying industries ranging from food processing to deep sea mining.

Pay attention to the "Recommended Area" column. A common mistake is using aluminum enclosures in areas with constant humidity and salt fog. As soon as a chip appears on the coating (and it will inevitably appear), pitting corrosion begins, which quickly eats through the metal. In such cases, savings at the procurement stage result in replacement of the entire equipment fleet within a year. For the food industry, where frequent washing with aggressive alkalis is important, plastic often outperforms metal, since it does not react with chemicals and does not require painting, which can chip.

System integration: cable routes and connection points

The most secure system is only as strong as its weakest link. In 90% of cases, a leak occurs not in the device body, but at the cable entry point. Extreme equipment protection IP68 and above requires a comprehensive approach to the cabling infrastructure. The use of ordinary household seals is unacceptable. You need cable glands that are certified to the same standard as the main equipment.

The key point is that the diameter of the cable matches the diameter of the sealing ring of the gland. If the cable is thinner than the gland rating, even strong tightening will not ensure a tight seal; the rubber will simply crumple, but will not crimp the cable evenly. The solution is to use oil seals with several stages of sealing or special reducing inserts. It is also critical to secure the cable inside the housing. In the event of an accidental jerk, the cable should not be pulled out along with the seal, opening the way for water.

For connections under water or in flooded areas, conventional junction boxes are not suitable. Here, sealed couplings filled with a compound (gel) are used. The gel displaces water and air, preventing oxidation of contacts and the formation of condensation. Such connections are considered maintenance-free and can remain under water for years. We recommend using two-component polyurethane gels, which remain flexible over a wide range of temperatures, as opposed to cheap silicone alternatives that dry out and crack over time.

Another aspect is shielding. In industrial environments with high-power frequency converters and welding equipment, the cable must be shielded and the screen must be grounded along its entire length. Violation of the shield at the input point due to the use of a plastic seal without a metal cage results in signal interference. There are special EMC seals that provide both IP68 sealing and screen continuity. Ignoring this aspect leads to false alarms, which in extreme conditions can cost lives or lead to accidents.

Standards and certification: how to verify the authenticity of protection

The market is saturated with products that boast IP68, but the reality is far from what is stated. To weed out low-quality goods, it is necessary to require confirmation of compliance with international standards. The main document is IEC 60529. However, there are additional requirements for specific industries. For example, for equipment used in hazardous areas (oil and gas, chemical), IP68 protection must be part of the general Ex certificate (ATEX, IECEx). An explosion-proof enclosure must withstand an internal explosion without destruction and prevent the spread of flame outward.

In Russia and the EAEU countries, an important quality marker is the EAC (Eurasian Conformity) mark. The presence of the declaration TR CU 004/2011 “On the safety of low-voltage equipment” is mandatory. But for extreme conditions, one declaration is not enough. Look for test reports from accredited laboratories. The document must clearly state: “The product has passed the test of immersion in water to a depth of X meters for Y hours.” If the protocol contains the general phrase “meets the requirements,” this is a reason for doubt.

It is also worth paying attention to MIL-STD standards (US military standards), which are often used as a standard of reliability even in the civilian sector. MIL-STD-810G vibration, thermal shock and salt spray tests provide much more information about the actual survivability of equipment than a dry immersion test. Products that have passed such tests usually cost more, but their fault tolerance is many times higher. For critical infrastructure, such as hydroelectric power plants or wastewater treatment systems, overpaying for certified reliability is insurance against multimillion-dollar downtime losses.

We recommend carrying out incoming inspection of a batch of equipment. Select 2-3 samples at random and perform a simplified leak test (e.g. placing in a container of pressurized water if possible, or visually inspecting the quality of the castings and seals). The presence of burrs on the body, unevenness of the sealant layer or the smell of cheap rubber are sure signs of counterfeit or low-grade products.

Business case: why a cheap solution is expensive

When purchasing industrial equipment, managers often focus on the initial price (CAPEX). However, in the extreme protection segment, the rule applies: “The miser pays three times.” A cheap device labeled IP68, purchased from an unverified supplier, has hidden Costs of Ownership (TCO). Let's do the math. The cost of replacing a sensor at a depth of 10 meters or in an operating reactor includes not only the price of a new device, but also the cost of stopping production, the work of divers or special equipment, and a downtime line.

In one of our projects, replacing a cheap level gauge cost the customer 15 times its original cost due to the need to drain the tank and clean out sediment before installing a new one. Reliable equipment with honest IP68/IP69K lasts 10-15 years without intervention. A cheap analogue requires replacement every 2 years. Over the next 10 years, you buy 5 units of cheap equipment versus 1 unit of premium equipment, plus you incur enormous service costs.

In addition, reliability affects personnel safety. Equipment failure under extreme conditions can result in toxic release, fire, or electrical shock. Regulatory fines and reputational losses in this case are not comparable to the savings on procurement. Therefore, when choosing a supplier, we recommend that you evaluate not only the price per piece, but also warranty obligations, the availability of a service network and the history of failures of similar models under similar conditions.

An investment in high-quality extreme protection is an investment in the predictability of business processes. When you know the sensor will not fail during a rainstorm or acid wash, you can plan production without the risk of unplanned shutdowns. This confidence is worth the money.

The role of specialized production in ensuring reliability

Theoretical knowledge about standards is important, but it is worthless without the ability to physically implement it. This is where specialized manufacturers come into the picture, capable of turning extreme protection requirements into working equipment. A striking example of this approach is the companyWuxi Kaisheng Electric Power and Petrochemical Equipment Co.,Ltd" Specializing in the design and manufacture of complex heat transfer and petrochemical equipment, the company demonstrates how the right choice of materials and strict adherence to standards create products that can survive the harshest conditions.

From titanium shell-and-tube heat exchangers to high-pressure ASME heat exchangers, Wuxi Kaisheng's products are designed to withstand the same factors we discussed above: corrosion, high pressure and extreme temperatures. The use of C46400 marine brass, C70600 copper-nickel alloys and N06625 nickel alloys allows their equipment to operate in harsh environments such as seawater desalination or oil refining, where conventional metal would quickly fail. Certification according to PED and ASME standards confirms that the declared characteristics are not just words, but the result of rigorous testing.

The experience of such manufacturers shows that true protection of IP68 and above is achieved not only by sealants, but also by an integral approach: from the choice of tube sheet alloy (for example, 321 stainless steel) to the design of air coolers and recovery boilers. When selecting a supplier for mission-critical applications, look for partners who, like Wuxi Kaisheng, offer customized solutions and have proven experience in global energy and shipbuilding projects. Their ability to deliver consistent equipment around the world means that their products are tested by reality, not just laboratory tests.

Frequently Asked Questions

Can IP68 equipment be used in seawater?

Only if the case is made of AISI 316L stainless steel or titanium, and all screws and fasteners also have an anti-corrosion coating. Standard IP68 on a plastic or aluminum case in seawater will quickly lose its seal due to corrosion of metal parts and degradation of plastic under the influence of salt and UV radiation. Be sure to check with the manufacturer about the resistance of your specific model to salt spray (Salt Spray Test).

What is the difference between IP68 and IP69K, and can they be interchanged?

No, they cannot be interchanged. IP68 guarantees protection against prolonged immersion in water under static pressure. IP69K guarantees protection against high pressure hot water jets (washing). An IP68 unit may not be able to withstand the water hammer of a high pressure washer, which would rupture the seals. Conversely, a device with IP69K usually has immersion protection, but this needs to be checked in the documentation. IP69K is required for food production.

How often do you need to check the tightness of equipment in extreme conditions?

The recommended visual inspection interval is every 6 months. A complete check of the tightening torque of the terminals and the condition of the seals - once a year or after each extreme event (storm, water hammer, chemical attack). If equipment operates under constant vibration conditions, fasteners should be inspected quarterly, as vibration loosens connections the fastest.

What to do if condensation appears inside the IP68 housing?

This is a signal of a temperature imbalance or microdamage to the seal. Disconnect the device immediately. Blow through the housing with dry compressed nitrogen (not air, so as not to introduce moisture again). Install a breather valve with a Gore-Tex membrane, which equalizes pressure but does not allow water to pass through. If condensation recurs, replace the O-rings; most likely, they have lost their elasticity.

Conclusion and next steps

Extreme equipment protection IP68 and higher is not just a number in a catalog, but a complex engineering system, including the choice of materials, correct design of sealing units and competent installation. Errors at any of these stages will negate all the benefits of even the most expensive device. The market offers many solutions, but only a few manufacturers are ready to confirm their claims with real test reports under conditions close to combat.

We analyzed dozens of cases of failures and successes to formulate the main conclusion: do not skimp on the protection class where the cost of an error is measured by stopping production or human safety. Choose suppliers who speak to you in technical terms rather than marketing slogans. Check certifications, ask for test samples, and don't be afraid to ask tough questions about operating limits.

If your project requires deployment of equipment in hostile environments, underwater areas, or extreme temperature conditions, do not take risks by relying on general descriptions. Our team is ready to audit your current technical assignments and offer solutions that actually work in the field, and not just in the laboratory.Contact us todayfor consultation with an expert engineer on sealing and protection of industrial electronics. We will help you choose a configuration that will ensure uninterrupted operation of your enterprise for decades to come.