Pres-Vac sets the standard for the valves of the future
For decades, Pres-Vac has been a major player in advanced valve solutions for tankers and dual-fuel vessels. According to Jens Reimer, the company’s long-serving Head of Regulatory Affairs, the mission is not only to keep up with developments, but to actively shape them through innovation and regulatory collaboration. This work has led to new technologies and opened the door to stricter environmental regulations.
The maritime industry is undergoing a profound transformation, with increasing demands from international authorities for reduced emissions and improved safety. Shipowners and shipyards now face a complex puzzle of technological and regulatory challenges, where short-term decisions on the right solutions can mean the difference between compliance and operational restrictions.
Jens Reimer has spent decades working with both the development and regulation of maritime systems, especially in relation to VOC (Volatile Organic Compounds) emissions from tankers. He participated in the working group of the International Maritime Organization (IMO), which in 2017 introduced a requirement for all ships to document their emissions. The long-term goal was to provide a tool for reducing environmental impact. This heightened focus on emissions from fuel and cargo tanks has also drawn attention to the large amounts of VOCs released through pressure relief valves.
“These are significant quantities. A Norwegian study from years ago, commissioned by the International Association of Independent Tanker Owners (Intertanko), showed that the annual evaporation from cargo and fuel tanks globally – caused by pressure changes during sailing and loading operations, as well as manual venting due to a lack of trust in the valves – equates to the contents of six to eight large tankers,” says Jens Reimer.
This translates into millions of tonnes of oil and VOCs released each year through pressure valves, resulting in financial losses and environmental consequences. As the industry becomes more aware of this problem, spurred by documentation requirements, the demand for more precise and intelligent high-velocity valve solutions is growing.
Innovation, regulation, and the next steps for dual-fuel vessels
“The need to trust valve performance has grown significantly, and this is where we can offer something unique. At Pres-Vac, we have always been early adopters of new technologies that reduce emissions, ensure optimal operational safety, and meet or exceed the latest IMO requirements.”
Pres-Vac has developed a valve solution that combines weight and magnetic control. For more than 20 years, the company has refined this technology to eliminate the compromises of traditional valve types. Jens Reimer explains:
“In short, there are three types of automatic high-velocity valves on the market. Weight-based valves open at a specific pressure but induce overpressure in the tank as they open. They also close slowly, which results in unwanted VOC emissions. Then there are magnetic valves, which avoid overpressure but tend to close too late, again risking emissions. Finally, there are Pres-Vac’s hybrid valves, which combine the benefits of both. The weight ensures robustness and early closure, while the magnetic mechanism prevents overpressure during opening and speeds up the closing process in the final 20–30% of the valve’s movement,” says Jens Reimer.
IMO’s tightening regulations: Pres-Vac stays ahead
Pres-Vac is more than just a valve manufacturer – the company plays an active role in the regulatory work of IMO and ISO. Jens Reimer has for many years participated in the committees responsible for developing future standards.
In April 2025, the IMO adopted a new revision of the test standard IMO/MSC.1/Circ.677, which will directly impact all IMO-classified tankers and dual-fuel-ready vessels. From December 2026, all installed high-velocity pressure/vacuum valves must be tested and certified in accordance with the new standard. Among other things, this means that valves must be tested at the exact pressure setting used in the specific project, and leakage levels must be documented and comply with the requirements of ISO15364:2021 Annex J.
Additionally, fire and flame arrestor tests must be conducted using the actual pipe length on which the valve will be installed, in accordance with ISO16852:2016. For ships under 18,000 DWT, an endurance burn test is also required.
Type approval must include details such as:
- The exact pressure setting
- MESG value (Maximum Experimental Safe Gap)
- Approved pipe diameter and length
- Break-off ICE thickness
“We’re often mentioned in IMO regulations because our technology sets new standards and helps raise the bar for future rules,” says Jens Reimer.
One example is the ongoing revision of IMO/MSC/Circ. 680, where the Norwegian authorities have proposed raising the allowable tank pressure on oil tankers.
“The regulation is expected to be adopted and implemented within the coming year – and Pres-Vac’s valve is one of the few that can already handle it,” explains Jens Reimer.
Certifications, safety, and 220-metre pipelines
Shipowners need solutions that meet both current and anticipated requirements over the next 5–10 years.
“It’s vital that shipowners know exactly how much they emit, and that they have valves that close quickly enough to minimise VOC emissions. This has become even more relevant with dual-fuel vessels,” says Jens Reimer.
The green transition has brought increased focus on methanol as a key alternative fuel for dual-fuel ships. This places stricter demands on valve systems, as methanol gas has the following characteristics:
- Methanol has a lower density than air (1.14 g/l), meaning it rises quickly
- It evaporates at lower temperatures than conventional fuels, requiring precise pressure control to avoid emissions
- It is highly flammable, and valve systems must ensure that flames cannot travel back through the pipe system
Pres-Vac has achieved unique certifications enabling valve installation on methanol-fuelled ships with pipe lengths of up to 220 metres – a certification unmatched by any competitor.
“It’s been a technical challenge to ensure proper ventilation on such long pipelines, but our solutions have been tested to withstand flame transmission and maintain stable gas flow even on some of the world’s largest ships,” says Jens Reimer.
Smaller vessels and the specific challenges of ferries: shorter pipes, higher speeds
While large tankers struggle with long pipelines, ferries and smaller vessels face a different issue: the proximity of emissions to deck areas due to shorter pipes requires that emissions be dispersed quickly and safely.
“For smaller vessels and ferries, there are strict requirements regarding how fast gases must be transported away from air intakes,” explains Jens Reimer. “To meet these new demands, we’ve developed valves capable of handling speeds of at least 60 metres per second at the required flow rate, ensuring emissions are safely dispersed away from the ship.” Methanol gases, when mixed with nitrogen, are the same density – or slightly lighter than–air and can therefore rise quickly. However, this still requires a precisely functioning ventilation system, especially on passenger ferries, where passenger safety is paramount.
Testing tools for large oil tankers: reducing gas leakage
One of the oil industry’s biggest challenges is gas leakage, including NOx and SOx from engines, and methane from cargo. When large oil tankers transit routes like the Panama Canal, they are subject to so-called “gas sniffer” tests that measure how much gas is escaping.
“About 25% of ships fail this test on their first attempt, which causes transport delays and can result in significant financial penalties,” says Jens Reimer.
Pres-Vac has developed a “resilient seal” – a soft seat that works together with the metal seat. This dual solution is certified to today’s standards and ensures tight valve sealing.
Pres-Vac is also developing a new testing tool that will enable onboard valve function checks, without disassembly.
“Once we’re ready with a method that allows vessels to test valves without removing them, shipowners will save time and money, while ensuring compliance with emissions standards,” explains Jens Reimer.
Balancing technology, regulation, and safety
Pres-Vac operates at the intersection of technology and regulation. While the IMO continues tightening requirements, the company is working to develop solutions that not only meet standards but help shape them.
“We participate in regulatory work with the IMO and ISO because we want to ensure that new rules are based on real technology and practical solutions,” says Jens Reimer.
For shipowners and shipyards, this means one thing: investing in Pres-Vac’s solutions is not just a guarantee of today’s compliance – it’s a safeguard for future competitiveness.