Posted on 16th August 2019
Exposure to excessive amounts of toxic substances or to an environment that is deficient of oxygen can cause crew serious harm or even death. Combustible gas explosions can also be incredibly hazardous and, in addition to putting the lives of crew in danger, may destroy cargo and equipment as well as damaging the vessel itself.
Regular tests using gas detection equipment are intended to protect crew and vessels from unknown hazards onboard. Tests are typically used to check and maintain safe levels of oxygen in enclosed spaces, monitor levels of oxygen in inert gas and inside tanks, measure the flammability of hydrocarbon gas, measure levels of hydrocarbon gas prior to entering pump rooms and other enclosed spaces and to locate and measure other potentially toxic gases within a ship.
In the continuing drive to improve maritime safety, the regulatory bodies of the maritime industry are constantly trying to improve gas detection and measurement by introducing new guidelines. The latest regulation from the International Convention for the Safety of Life at Sea (SOLAS) which came into force in July 2016, made it mandatory for all applicable vessels to carry portable gas detectors onboard.
According to Regulation XI-1/7, every ship is to carry at least one appropriate portable atmosphere testing instrument. As a minimum, this must be capable of measuring concentrations of oxygen, flammable gases or vapours, hydrogen sulphide and carbon monoxide, prior to entry into enclosed or confined spaces.
As stated in Regulation MSC.1/Circ.1477: ‘It should be noted that, given a ship’s specific characteristics and operations, additional atmospheric hazards in enclosed spaces may be present that may not be detected by the instrument recommended to be selected by these Guidelines, and in such cases, if known, additional appropriate instruments should be carried.’
Most modern portable gas detectors are designed to monitor multiple gases. To be able to carry out tasks effectively there is a wide range of instruments, both fixed and portable, that are suitable for use on ships. Each unit is usually calibrated for a specific gas and some have dual functions, such as combustible gas and oxygen.
It’s important to understand the limitations of the instruments, as well as their function and method of use. That’s why handbooks from the manufacturer should always be consulted for full information on the instrument before use. The need for gas detection and measurement equipment and therefore, the need for calibration is growing.
In simple terms, calibration means checking an instrument or piece of equipment to meet a defined specification. It involves measuring the accuracy by comparing it with a set standard and, if necessary, making adjustments to bring it to the correct alignment.
Gas detection and analysing equipment will only give accurate readings if calibration is carried out using the correct calibration gases in accordance with the instructions of the manufacturer. Instruments must always be checked and spanned when necessary as well as zeroed using pure gases such as nitrogen (99.999% N2).
To ensure accurate readings and to maintain reliability, it’s essential that all gas detection instruments undergo a regular schedule of calibration and testing. All equipment, both fixed and portable, must be adequately checked before use and records kept of these checks – including details of any faults that may have been found.
Calibration gases – also known as span gases – are gas mixtures which are used as referencing tools. They act as a comparative standard in the calibration of analytical instruments, such as gas analysers or detectors. Exposing an instrument to a verified concentration of test substance will gauge whether the sensors respond accurately to that gas. Given their use, calibration gases must therefore be exact and traceable to a national or international standard.
There are many different mixtures and pure gases available. Marine industry calibration gases typically comprise of:
– hydrocarbons and air mixtures
– hydrocarbons and nitrogen mixtures
– carbon monoxide or hydrogen sulphide mixtures
– oxygen and nitrogen mixtures
– pure gases such as nitrogen (99.999% N2) and methane (100% CH4).
Reputable calibration gas suppliers will provide a wide range of mixed gases as well as a large range of regulator flow rates, typically ranging between 0.5 and 3 litres per minute (LPM).
Martek Marine provides a range of quad gases for the accurate calibration and testing of portable multi-gas detectors, such as: 20ppm H2S, 60ppm CO, 1.45% CH4, 15% O2/N2 and 25ppm H2S, 100ppm CO, 1.1% C3H8, 19% O2/N2. We also supply high quality cylinders for fixed gas detectors.
The Chief Officer is responsible for identifying, monitoring, calibrating and adjusting all portable and fixed gas measuring instruments.
In addition to ensuring that an adequate amount of the correct grade of gas is readily available, equipment should always be marked with the due date of the next calibration and should not be used if this is overdue. Certain instruments may even need to be calibrated ashore.
Buying calibration gas has traditionally been quite challenging. It usually involves chasing quotes, being charged too much and dealing with administrative nightmares. However, Martek is offering a fresh approach to calibration gas supply which allows you to focus on keeping your vessels safe rather than getting tied up with the hassle of keeping them supplied.
FastCalGas is a fully managed service – a one-stop-shop for calibration/span and quad gas. Martek know when your gas is about to run out and will send an alert in good time to make sure that your equipment never misses its calibration. Customers can purchase quickly and easily online, anytime and anywhere in world and we will deliver directly to your vessel just when you need it. We’re the only calibration gas supplier that offers this unique service.
98% of gas orders are shipped within just 24 hours. Unlike many gas companies, Martek is fully immersed in the marine industry so we know the challenges related to working on and around ships. We’ve combined this experience with our specialist knowledge of calibration gas and the transportation of hazardous goods.
We’ve been in the gas supply business for many years, so we know how to ship gas quickly using lean order processing and an extensive global supply chain.
Martek has been supplying gas to the key OEM’s in gas detection for over thirteen years and we’re already the gas supplier of choice for the major oil and gas companies worldwide.
By using the best, high-quality materials, our gases have a 27-month shelf life – the highest shelf life in the industry. We’re also quality assured to international standards which is backed up by our ISO9001:2008 certification.
When it comes to disposing cylinders after use, you could send your empty cylinders to a scrap metal agent where they might be worth up to $2 each. However, all gas cylinders are potentially recyclable. We supply a low cost, simple recycling tool that creates a defect in the valve and makes the cylinder unusable.
We have stocks of gases in key markets including the UK, UAE, Singapore, the USA, Netherlands and China. Global stockholding enables us to keep our prices low and our supply fast. We will even hold gas stock on your behalf at any of our global gas hubs.
To help with your cash flow, after a successful credit check we can also offer a 30-day credit terms on gas orders up to £4,000.
We know that changing supplier can be a risky business and that’s why we’ve introduced our ‘Lifetime Happiness Guarantee.’ If you’re not happy with any aspect of our service or support, then we will give you your money back, PLUS an additional 10% for the inconvenience. We’ve made the process of changing supplier financially risk-free.
Contact us to find out more.