Advantages Of Electronic Portable Tank Gauging
The International Maritime Organization (IMO) has mandated certain directives concerning the measurements of cargo onboard tank ships, including oil/water interface detection for slop tanks, tank dryness dipping and the percentage of oxygen in the inerted ullage space of cargo tanks.
These mandates offer new challenges for the improved supply of portable electronic tank gauging instruments (ullage, oil/water interface, temperature measurements and oxygen sensing) with associated mechanical cargo sampling and sounding tapes and accessories. Two of the most prestigious petroleum technical associations — the American Petroleum Institute and the Institute of Petroleum Engineers — are continually updated their standards for restricted and closed (gas-tight) gauging, sampling and sounding, providing worldwide industry guidelines for the acceptance of these portable measuring devices.
In addition to the gauging, sampling and sounding standards, the API and IP have updated their oxygen-sensing standards. The advent of restricted and closed (gas-tight) gauging provides a number of significant advantages, including saved time and labor, improved accuracy and repeatability, and reduced atmospheric pollution.
Moreover, the electronic sensing capabilities of these types of portable gauging systems allow gaugers with less training and experience to operate equipment, with more reliable results than in the past.
In order to change from open gauging to restricted or closed gauging, shipowners are required to install at least one vapor lock (vapor control valve) on each cargo and slop tank. This gives operators tank access for electronic tank gauging instruments, along with sampling, sounding and oxygen sensing equipment. This portable combination (UTI gauging tape and vapor lock) achieves two results for independent surveyors hired to verify the quantity of cargo loaded or ready for discharge. The high quality portable gauging equipment available today delivers excellent resolution. The preceding was excerpted from a paper from William Henry, president, MMC International Corp. MMC International is a leading manufacturer of portable gauging equipment. MMC vapor control valves and gauging tapes are in service on thousands of tanker
