Representative sampling : The key to safety success & regulation compliance
Sentry Equipment ’ s director of business development , Horacio Salinas , discusses the importance of reliable sampling systems and their many roles in speciality chemical plants
The speciality chemicals industry produces various substances for many applications , including paints and inks , detergents , pharmaceuticals and biocides for agricultural uses . Due to their impact on multiple products within a multitude of industries , there are robust compliance , quality and hazardous material transportation standards that plants must meet to ensure product safety .
Beyond complying with local , national and international regulations , a manufacturer ’ s commitment to quality and safety leads to maintaining the highest industry standards and numerous national and international certifications . With how the standards and rules work to foster customer loyalty , profitability and safety , they could also apply to the sampling method a company might choose .
This is particularly true in the speciality chemical market , where safety and quality are not goals but requirements . By contrast , sampling does not fit neatly into the organisational structure of refineries and petrochemical plants . There are multiple stakeholders with an interest in sampling — from quality lab technicians to operations personnel to safety managers — but no obvious ‘ owner ’ of the sampling programme . This has left many operating without the expertise required to ensure safe , consistent sampling , thus jeopardising product quality and operator safety in the process .
While plant capital assets , like sampling systems , are a significant investment , they are vital to maximising production output and profitability . Technicians should regularly collect , condition and analyse representative samples to obtain a real-time view of the stream condition and assess its impact on processing equipment . Neglecting to monitor the process increases the risk of catastrophic equipment failures , environmental spills and fatal accidents .
What is representative sampling ?
Representative sampling captures a small volume of material from a process stream that accurately reflects the condition of the entire lot , batch or process stream . Operators can sample most process materials , either within a production environment or after storing or transporting them . Engineers then analyse the sample for product quality and process monitoring .
Two primary methods of collecting samples are grab sampling and representative or composite sampling . The former is a manual process in which technicians use a spigot to duct the sample into a bucket or scoop it into a bin . These methods reflect the condition of the process stream at the time the sample was collected .
Representative or composite sampling methods collect multiple individual samples at regular intervals over a defined period using applicationappropriate sampling techniques . Such an approach makes a more customised strategy possible .
Designing the right system
The accuracy of sample analysis is only as good as the condition of the sample material for both external and in-line sample analyses . In addition , it is critical to design the sampling method for the specific process stream type , process conditions , sample type and material properties .
Table 1 shows some of the key parameters . Depending on these , a sampling system can be customised entirely according to specific users ’ needs . The most crucial factor is that many samples may need to be conditioned by bringing the temperature , pressure and flow rate to a state suitable for reliable analysis . Without proper conditioning , the sample analysis results could lead to misguided operational decisions that directly impact customer loyalty , profitability or safety .
Material compatibility is another critical consideration throughout the equipment selection process . In the speciality chemicals industry , everything from the sealing materials to the pressure level and temperature
54 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981