PTQ Q4 2023 Issue

lancet point needle can accidentally cut or ‘core’ the sep- tum, which allows fluid to escape. Instead of using a lancet needle, designers should consider using the pencil point needle since it offers less chance of damaging the septum. For gas or volatile liquid sampling systems where cylin- ders are involved, it is important to use cylinders that fea- ture easily operable quick connects that provide efficient and safe connecting and disconnecting from the sampling point. Limiting emissions by preventing the exposure of process fluid to the environment and operators is best handled by well-designed, closed-loop grab sampling systems. Using the right panels can minimise emissions and risks, make it easier to train operators, and reduce the potential for errors. In fact, with ongoing hands-on training and education, operators can eliminate sampling system mistakes before they occur. Such training will help them better anticipate errors and recognise existing problems in installed sam- pling systems. Safer, more efficient ammonia sampling Anhydrous ammonia is commonly used in chemical plants and refineries in the production of fertilisers, plastics, tex - tiles, petroleum, and more. It must be sampled periodically to verify it has a water content of 0.2% to 0.5%, as concen- trations outside this range may lead to product quality con- cerns and the potential for severe stress corrosion cracking to occur on storage tanks. However, during traditional sampling operations, ammonia can be a nuisance source of fugitive emissions, as well as a safety hazard for operators collecting samples. Operators traditionally sample ammonia using standard methods such as CGA G2.2, in which a 100 mL sample of liquid ammonia is dispensed and then allowed to evapo- rate. They can then easily calculate the sample’s water con- tent by measuring the residual water. However, this manual sampling process can be dangerous, as it can expose oper- ators to harmful ammonia liquid and vapours, while also releasing those elements into the atmosphere. There is also an increased potential for inaccurate and inefficient results if any part of the sampling process goes awry. In traditional ammonia sampling processes, operators must wear a significant amount of personal protective equipment (PPE) – including goggles, gloves, respirators, and chemical suits – due to potential exposure to liquid ammonia and vapours. Ammonia can cause severe skin burns and eye irritation, and is toxic if inhaled. Released into the air, it can also negatively impact the environment. A semi-automated, closed-loop sampling system design can eliminate the above issues by minimising hazardous operator exposures, ensuring consistency in the collection process, and producing faster results, which in turn allows facilities to make quicker process adjustments. Closed-loop sampling systems can enhance safety by limiting operator exposure and environmental impact. Such systems feature closed sample fixtures, which prevent liquid or vapours from escaping or flashing into the atmosphere. With limited to no exposure potential, operators can also avoid donning excessive PPE.

low-emission (low-E) valves, which pass rigorous tests designed by the American Petroleum Institute (API) to keep fugitive emissions low, can be used in the sampling sys- tem design to reduce potential leak points. Most systems are constructed with certified low-E valves and leak-tight quality components because emissions regulations have become so strict. Though using high-quality valves and fittings can signif - icantly reduce the number of leaks, it will not necessarily eliminate all potential leak points. Smart system designers are building fluid systems using as few connection points as possible. Fewer connection points mean fewer chances for leaks to occur, and if leaks persist despite the use of high-quality components, the problem may be attributed to poor installation practices. It is important that your grab sampling systems have been assembled and tested by trained specialists so these problems do not arise. Finally, the connection point at which the technician col- lects the sample in a bottle or cylinder provides another chance for the liquid or gas to leak. Several technologies can stop these leaks before they happen. For liquid closed-loop systems where the sample is col- lected in a bottle, a needle typically pierces a rubber sep- tum to allow the liquid to enter. However, using a traditional Figure 4 Transparent glass pipes and collection vessels in a closed-loop ammonia sampling system enable visual confirmation of the sampling process and ensure the capture of consistent sample sizes for testing

PTQ Q4 2023